Confusing Concepts - Diffraction

OF THE 3 different concepts in this 3-part series, this one is probably the most technical, the most difficult to understand, and the most difficult for sure to explain. Sensor resolution, we saw, was really just a matter of the relative size of the "container" (the sensor size), the size of the individual photo sites (pixels), and the number of photo sites within a given sensor dimension. We also said, however, that these things don't work in a vacuum. A sharp, detailed (resolution) image is affected by not only the pixel number and size, but also by diffraction. The creation and presentation of a digital photographic image is not a precise science. In fact, I am going to introduce a term that will be central to the final post about image sharpness: "appearance." We probably really ought to refer to image sharpness in a digital photo as "apparent sharpness." The reality is that there is no absolute sharpness - only apparent sharpness). What do I mean by that? Stay tuned for the third and final installment of this series: "Confusing Concepts - Image Sharpness."

The creation and presentation of a digital photographic image is not a precise science

THE EFFECT of diffraction on a digital image is a strongly related concept, however. To make a photographic image with virtually any camera and/or medium, we must focus rays of light through a lens. We mentioned in the previous installment that almost all lenses are circular. A primary reason for this is that the circular coverage provides the most consistent coverage of the rays of light smoothly from side to center. The round lens, however, "bends" the light rays, which generally requires a series of glass elements to - if you will - "unbend" them. 

WHY DOES any of this matter? Diffraction occurs during the process of  "bending" the light through the lens. What causes diffraction is the light waves that diverge from parallel. As a general rule, diffraction is effected by the size of the opening that the light waves pass through, and the length of the light wave. Let's address opening size first. There are going to be two mechanical factors: First, the  physical size of the lens circle at its widest aperture (which is what brings relevance to the above "coverage" discussion) is constrained by design. It follows that we should experience less diffraction from the larger openings of lenses designed to cover larger sensors. Confoundingly, as our apertures get larger, the depth of field of an image gets more shallow, so from front to back the apparent sharpness of the image seems less. Somewhere, "the twain shall meet," creating the "sweet spot" I talk about below.

THE OTHER mechanical factor is lens aperture (within a given system). Generally, the smaller the aperture (for the same reasons as the size of the physical lens circle matters), the more diffraction, and vice versa. Note that I have referenced lens "size," and lens "aperture." I did not say f-stop number. Why? Because a given f-stop varies in physical size between different lenses. This is true both in terms of focal length within system, and different system lenses (i.e., an M4/3 lens f8 will be physically smaller than a "full frame" lens at f8).

ANOTHER THING that effects diffraction is the length of the light waves. Again, as a general proposition, shorter waves diffract much sooner than longer waves do. Think about the spectrum of light. Blue light waves are among the very shortest (those who understand polarizing filters are probably familiar with this). This explains what certain light conditions demonstrate the effects of diffraction more than others.

Every Lens has its own "sweet spot"

EVERY LENS has what we sometimes refer to as its "sweet spot." That is where it is at its absolute sharpest performance. Most of us have an awareness that  many lenses are not sharp across the frame at their most wide open apertures. We also have a general awareness that as we stop down the aperture, we tend to get increasingly (apparently) sharp images. Some of us have been aware, over the years, though, that there is a point of no return, where not only does the lens no longer render an increasingly sharp image, but the image might even degrade some. This degradation is due to diffraction. Recall above that we said diffraction increases as the lens opening gets smaller. This is why it is important to keep that "sweet spot" in mind. Generally, a "full frame" (35mm equivalent) lens will be at its sharpest at f8 - maybe f11. An M4/3 lens will probably be at somewhere between f4 and f5.6. We will talk about why there is a difference shortly. All of this is, of course, also limited by lens design and overall quality. So-called "cheap glass," or zoom lenses trying to encompass too much zoom range, will mechanically and optically also negatively effect image quality, sometimes introducing optical and color aberation, and lack of contrast.

THERE IS another factor in the diffraction discussion other than lenses. Perhaps the most significant factor is sensor and pixel size. Once again, smaller pixels will be more susceptible to the effects of diffraction. That is the primary reason we find that "sweet spot" in M4/3 lenses to be at a wider aperture (f4- 5.6).

THE CONTRIBUTORS to diffraction mean that there is an aperture on each lens that is that "sweet spot." While we have generalized, each lens has its own "spot" and you may need to do some empirical testing of each of your lenses to arrive at that spot. It is important to acknowledge that there will always be some diffraction at every lens aperture. That point where it becomes visibly deleterious to image qualilty is referred to as the point where the lens is "diffraction-limited." My definition here is, of course, overly simplified. The simplest "technical" definition I could find was: "The diffraction limit is the maximum resolution possible for a theoretically perfect, or ideal, optical system." Think back to our discussion of "resolution." They are interdependent, and this "technical" definition feels awfully circular to me. The ultimate conclusion for me is that diffraction is one of the primary factors which effect image quality (without regard to the quality of the equipment being used), along with resolution and sharpness.

We shouldn't let all this technical jargon get in the way of our creativity

DOES THIS all mean that you should always and only shoot at the "sweet spot" aperture of your lens? Of course not. As I am fond of saying here, all of photography is a compromise. The artistic part of composition means that we must work with the limitations of the tools. Sometimes we want very shallow depth of field. Sometimes we want the image to be crisp from front to back (one of the ways photographers have been dealing with this issue in still photographs, by the way, is a phenom called "focus stacking"). But we shouldn't let all this technical (sometimes pixel peeping) jargon get in the way of our creativity. It is just useful to know the limits of our equipment when applying it to our craft. Next time we will address that third factor: Image Sharpness.

Confusing Concepts - Resolution

VOLUMES UPON volumes have been written about this topic. I am not for a moment trying to convince you that I am either an expert or the proverbial "last word." In recent weeks, I have read a few comments here, and online in other blogs (mostly in the discussion and comments) that seems to me to underscore a lack of complete understanding of the terminology. What motivates this blog (and a couple more to follow) is the thought the maybe I can shed some - albeit elementary - light on these topics. This is the first of a 3-part series.

PART OF the confusion probably stems from the fact that there are actually different kinds of "resolution" when we apply it to photography. It is a rather broad term, which is often used imprecisely. The making of a photographic image involves a lens, a medium - these days mostly a digital sensor and resulting file, and a manner of display. Each of these components applies a different "spin" on the word, "resolution." Consequently, when we are addressing resolution, we need to understand what kind of resolution we mean.

Sensor Size Comparison

THE RESOLUTION of a particular camera lens (or its "resolving power), simply refers to its ability to resolve detail. There are numerous factors that effect this ability, including lens design, size and quality of the glass elements, coatings, etc., 

IN THE case of digital cameras, resolution refers to the sensor used to record the digital image. This component of the optical "system" is perhaps the most difficult to get one's arms around. Sensors are intricate mechanisms. On a rudimentary level, they seem simple enough. They are just a collection of electronic recording sites (known as photo sites) grouped together on the camera sensor surface. They are, of course, microscopic in size. A more in-depth look at sensors leads us to realize that things aren't as simple as that sounds. Two significant factors are the size and number of individual photo sites. It seems evident enough that a smaller sensor will not be able to hold as many of the same-sized photo sites (or photo cells) as a larger sensor. Sensor size is functionally related to the lens circle. Smaller lenses will only "cover" a smaller sensor area. As the sensor gets larger, in order to cover the sensor area, lenses must be designed with larger circles. The reason lenses are circular is really beyond the scope of this article (and my expertise, 😰), but it is a matter of physics, and the desire to balance the light being directed by the lens. If you use an image sensor that is larger than the image circle, the image will show up framed as a circle encompassed by a black area outside the circle. As a general rule (we will see as we go on, that these things don't work independently), smaller photo sites will have less "resolving" power than larger ones. Coupled with the concept of an optical occurrence known as diffraction (stay tuned), conventional wisdom has it that smaller sensor - based cameras will generally have less resolving power than larger ones. While not precisely correct, it is a valid consideration when using such equipment. I have only recently empirically tested (and concluded) that this applies to my m4/3 camera setup as compared to my "full frame" sensor gear. The rationale for this line of thinking is that it is difficult to match photo sites in terms of both number and size on a smaller sensor. My Olympus m4/3 sensor is nearly 1/4 the size of my Sony a7Rii "full (35mm equivalent) frame" sensor. At only 20 megapixels (a measure of the number of photo sites on the sensor), it is the largest m4/3 sensor available, to the best of my knowledge. My Sony, on the other hand, is 46 megapixels (and the newest iteration - the a7Rv - is 61 mp). Not only are there from 2 -3 times the sites, but each individual photo site is also significantly physically larger. That phenomenon creates conditions for increased sensor resolution.

Bayer Color Filter Array

THERE IS more to the sensor story than photo sites and sizes though. Diffraction plays a significant part in this equation, too. I will cover diffraction all by itself in the next post. During the early years of digital sensors, one of the concerns that designers (and users, of course) had was the phenoma of "aliasing." As we have discussed here in the past, the basis of a digital image is the "lego-like" stacking of rectangular pixels to produce the shapes found in images. Because of these individual pixels, there are always straight line transitions between pixels (to continue the analogy, each lego block). At some level - particularly in lower "resolution" (in this case meaning smaller and less megapixels) images will have the appearance of jagged edges (or "jaggies"). In order to address this concern, camera manufacturers put an anti-aliasing filter in front of the sensor (known as a "low pass" filter), that was designed to introduce a bit of blur. Obviously, my explanation is hopelessly oversimplified and the process is/was complex, if not consistent. As they added megapixels (my first Nikon D100 was a 6mp camera), and processing software (especially raw conversion engines) got better and better, the aliasing issue has become less important. Indeed, I have personally looked for camera specifications that do not have the low pass filter, reasoning that I don't want anything I don't absolutely need to introduce softness. On the contrary, I am looking for the maximum sharpness I can get. In my view, the presence of an AA filter - though perhaps only very marginally - effects resolution. Neither of my current cameras (Sony a7rii and Olympus EM10iv) have AA filters on their sensor.

Why are the pictures square if the lens is round? - (Steven Wright)

 A SECOND filter (or filter array) known as a "Bayer Color Filter Array" is placed in front of the almost every digital sensor. Through a process called digital sampling, the sensor creates the digital image. The Bayer filter involves additional color sampling, which produces the colors in our images, using primary colors of red, green and blue. The sharp observer will note that there are (many) more green sensors than red or blue (see the illustration above). This is because our visual system is the most sensitive to the green light spectrum, which is where the sun emits the largest amount of light. Green light contributes much more to our perception of luminance. Color filter arrays are designed to capture twice as much green light as either of the other two colors. The takeaway here is that the Bayer filter is yet another path of interference between the light rays and the sensor sites. This introduces softness and therefore, effects resolution. This also explains why most raw processing software has a "default" amount of sharpening (often referred to as "capture sharpening") that is applied automatically to a raw digital file. Most software (Adobe ACR does) allows the user to adjust, or even eliminate, that default sharpening.

all of these individual measures of resolution work together to create the end product

THE LAST of my three resolution considerations is the manner of display. For many years, the primary method of display was the print, on a photographic fiber medium. This involved some kind of pigmentation process from being embedded into the medium (traditional photographic darkroom printing) to printing press ink printing methods to the more modern digital inkjet printing. By the time of the latter, we were also commonly projecting images onto a cathode ray type tube (CRT), and eventually, LCD screens. Prior to the emergence of digital, another method of displaying images was through what was called a color-transparency system (or simply slides). Each of these presentation methods react differently in terms of resolution. The medium itself has its own "resolution," which - once an image is put in the form of the presentation, becomes the predominant factor. With the ascendancy of social media, smart phones and tablets, it is probably safe to say that digital projection is the most common manner of presentation today. Resolution in the context of presentation media, has begotten perhaps one of the most confusing terminology puzzles in the realm of resolution. Resolution of an image when projected on a CRT/LCD screen is purely electronic and is often measured as pixels per inch (PPI), a measure of the size and density of the displayed image. When we speak of an inkjet print however, the printer uses colored pigments to create a microscopic dot-based pattern on the medium. The correct resolution terminology here is "dots per inch" (DPI). DPI is also used for traditional printing-press type media presentations. The two (PPI/DPI) are often - confusingly - interchanged.

AS I said earlier all of these individual measures of resolution work together to create the end product. When choosing and using camera gear, an understanding of these factors will make more sense out of your choices. When the hype from the seller, or the specifications from one of the testers out there emphasizes the particular component's "resolution," or "resolving power," it is important to think about the other components. The highest quality (think Leica or Zeiss) lens, with a "medium - format" sensor (or larger) camera (and yes, confoundingly, in the digital world, MF is bigger than "Full Frame"), that is going to be only seen on your FB or Instagram page is extreme overkill. The final digital resting spot for the image cannot begin to match the resolution of the other two components.

Resolution in the context of presentation media, has begotten perhaps one of the most confusing terminology puzzles in the realm of resolution

I  AM not saying you shouldn't have high quality or high resolution equipment. I am saying that an understanding of resolution and its significant variability will help put your photography - and your gear needs/wants in perspective. "Pixel peeping" is a (sometimes pejorative) description that is given to a lot of photographers these days who tend to place an over-emphasis on technical factors, like resolution, noise (see, What's All the Noise about Noise), and diffraction (another term I will cover in an upcoming blog), over the more artistic part of photography. To be sure, some fundamental skills and reasonably good quality equipment are required to make sure the image is going to be viewable as intended. But beyond that, in many cases, the technical issues tend to be overblown, in my opinion.

WE STILL haven't told the whole story though! Stay tuned for upcoming blogs on Diffraction and Image Sharpness.

GEAR WARS: The Sensor Strikes Back

THE STAR Wars story couldn't be a better example of the age-old plot: the good guys against the bad guys. The white hats against the black hats. Canon against Nikon. Ironically enough, back in those days, most of the Canon lenses were white and the Nikons were black. If you are old like me, you probably shot 35mm Single Lens Reflex (SLR) cameras. During those years, I used to see arguments about "which one is better" all the time. Many of them were good natured, but sometimes it got down into the trenches. Then: grab some popcorn and sit back for the show. Almost always a dark comedy. 😏

I SHOT both over the years (though mostly Nikon). I never looked at them with a "one-is-better-than-the-other" attitude. In my toolbox, I have two hammers. One is the Estwing brand and the other is Stanley. I kind of favor the look and feel of my Estwing - but really, both have the identical function. They drive (and pull) nails. And both work just fine for the task. Perhaps an overly simplistic comparison, but I have done so purposely - hopefully to make a point. Probably the two "best seller" hammers. There are many others, though, that perform equally well.

There ain't no good guy; there ain't no bad guy . . . 

THESE DAYS the "Gear Wars," are no longer between best sellers Canon and Nikon (in the mirrorless camera world the two best sellers are now Sony and Canon). Today the war has moved to a different battlefield: sensors. Still just as much a waste of time in my book, internet camera sites, blogs and social media pages/groups are often mired in arguments about whether certain M4/3 systems are as good or better than the so-called "full frame" (FF = 35mm equivalent) systems. There are, of course, other sensors that are smaller (1" and below - as in P&S cameras and smartphones), larger (so-called "medium format" which is - nonsensically - larger than "full frame"), and in between (the very popular APS-C sensors). The two major camps in the skirmish, though, appear to be the M4/3 against the FF.

TRYING TO keep my multiple metaphors under control, 😓 I want to repeat what I have harped on here before: (Dave Mason said it better than I can): There ain't no good guy; there ain't no bad guy, there's only you and me and we just disgree. As they always have been and always will be, these things are just tools!

The operative word here is compromise

THE RIGHT tool for the job, was something my dad and grandfather (both consummate craftsmen and engineers) repeated time and again to me over my youthful years (think of that time when you grabbed a butter knife from the kitchen to unscrew something). Sometimes there is more than one tool for the job. Sometimes there is only one. Surely there are poorly-made copies and brands out there, but when we are talking about the primary camera market, for the most part they are of equivalent quality manufacture. Because of that, the brand of screwdriver doesn't  matter as much as some of us might think it does. They aren't "better or worse." They are just different.

The two major camps in the skirmish . . . appear to be the M4/3 against the FF

I AM not for a moment saying there aren't differences, or that those differences are useless and unimportant. I am saying that we place an inordinantly heavy emphasis on them. Let me stay with the tool example for a bit. Same toolbox, different drawer. I have two full sets of ratchet drive socket wrenches (full disclosure: I actually have several more sets). One is 1/4 inch drive and one is 1/2 inch drive. There are many of the same size sockets for both drives. In that way, they both work (mostly) equally well for the job of tightening or loosening hex-head nuts and bolts. They are tools. There are also some larger sockets that are only 1/2 inch drive and some much smaller ones that are 1/4 inch drive. There are times when you need the larger one for more leverage and torque and times when the smaller one fits the space better. 

FOR THOSE not as into tools, you will probably have only one set. Much like choosing a single camera system, there are going to be compromises. As you can see from the above, sometimes one system will do things the other won't. The choice of a single system is going to be a compromise -something I also harp on here (for the tool-confused, there is also a 3/8 inch drive ratchet setup which is probably going to be the best compromise in most cases).

The right tool for the job

I ACKNOWLEDGE that we are talking about a sophisticated camera system costing thousands of dollars and not a mostly single purpose simple wrench or hammer. The oversimplification is my attempt to make a stark point. When it comes to a camera system, there are, of course, multiple functions that must be addressed. They vary from camera to camera, and it is the manufacturers, and not us, who decide which model has which features (I have often thought about how nice the now-ancient Gateway Computer model would be for cameras; where we pick our base model and then add or delete features we want or do not, ala carte). Unfortunately, that is not even slightly feasible. Instead the operative word here is compromise. When we look at the M4/3 system against the FF system, each is going to do things the other will not. I have talked in some detail about these differences in my series about image quality (Resolution, Diffraction, and Image Sharpness). I won't publish another "comparison" laundry list here. My primary point is that we buy camera systems for a variety of reasons. Some of them are well thought out and some aren't. I suggest we all look more toward the "well thought out" approach. What kind of photography will we be doing? Where will we be doing it (will airline or other baggage-dependent travel be in the mix)? What kinds of technology will we need? What will we be doing with the images once recorded (do we want to make/sell large, detailed prints, or sell our digital images to commercial third parties)? How much does size and weight matter to us?

FOR SOME of us, we just couldn't make the one-system compromise work for us. If you know me, or have read the "What's In My Bag," page here, you know that I shoot both FF and M4/3 systems, depending on some of the factors mentioned above. For travel that is not dedicated to photography, I carry and use the M4/3 system 99% of the time. For outings dedicated to photography (especially landscape stuff), I use the FF gear 99% of the time. I have a good friend and talented photographer in his own right, who has FF gear for shooting wildlife and "Medium Format" system for landscape. That is how we deal with too narrow a compromise. The key is that we have chosen these systems for thought out reasons, and do not care a bit that anyone else thinks their gear is "better." It's not. Its just different.

Changing of The Guard

Buckingham Palace - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

WHEN MANY of us hear: "changing of the guard," we think of our own infantry soldiers at "The Tomb of The Unknown Soldier" at Arlington National Cemetery in Virginia. Ironically, I don't have any photos from there. There are, of course, similar places in other countries around the world where there are guards and the shift changes are an impressive ceremony. As well, there are colorful guards, and changing-of-the-guard ceremonies around the world.

The changing of the guard at Buckingham Palace is more like a complete parade

Tomb of the Unknown Soldier - Athens, Greece - Copyright Andy Richards 2015 - All Rights Reserved

PROBABLY THE first of these that I photographed were during our second trip to the Mediterranean in 2015, in Athens. The changing of the guard ceremony at the Athens "Tomb of the Unknown Soldier" is very entertaining, with the Greek Soldier's unique uniform dress and high-stepping marching. 

Tomb of the Unknown Soldier - Athens, Greece - Copyright Andy Richards 2015 - All Rights Reserved

The Acropolis - Athens, Greece - Copyright Andy Richards 2015 - All Rights Reserved

WHILE THE ceremonies might be impressive, the soldiers are not mere ceremonial actors. For the most part, they are active-duty soldiers who rotate in and out of these roles, which having other potentially more serious military duties. And some of the facilities guards are more modernly dressed, like this group who paraded through the Acropolis, just as we entered. 

Guards at The Vatican - Rome, Italy - Copyright Andy Richards 2015 - All Rights Reserved

LATER DURING that same trip, we visited The Vatican. We did not see any ceremony or guard change, but the Vatican Guards certainly were colorful and photogenic. 

Buckingham Palace - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

WE SAW the greatest variety of guards, though, during our recent 2021 trip to England. It seems like there was a castle or palace everywhere we turned, and they all had guards, starting with the perhaps grandest of them all: Buckingham Palace. The changing of the guard at Buckingham Palace is more like a complete parade, with guards coming on horseback from the Horseguards Headquarters, from perhaps a half mile up the road - fittingly called The Mall -  from the palace.

Buckingham Palace - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

THERE ARE always guards on post at the palace gates, and at Buckingham, they are always adorned with the tall, black bearskin hats. 

Horse Guards Headquarters - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

THE QUEEN's horseback guards have a huge quartering and staging facility including a large yard, where the guards stage up for any ceremony or changing of the guard. They then proceed down the Mall to and from the Palace. The Horse Guards Facility is pretty impressive. I consider it a "must see" if you visit Westminster while in London - and you simply must visit Westminster. 😊

Horse Guards - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

WATCHING THE changing ceremony for the guard posts for the Horse Guards facility itself, is equally entertaining.

Horse Guards - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

 

Horse Guards - Westminster, England - Copyright Andy Richards 2021 - All Rights Reserved

 IN LONDON's Tower of London (once the primary castle for the monarchy built under William the Conqueror) had its own guards, who were correspondingly colorful and photogenic. As might be expected, there were guards posted at every gate, and around the grounds.

Tower of London - London, England - Copyright Andy Richards 2021 - All Rights Reserved

 I WAS particularly drawn to the guards around the building housing The Crown Jewels.

Tower of London - London, England - Copyright Andy Richards 2021 - All Rights Reserved

OUR VISIT to nearby Windsor, and Windsor Castle did not disappoint either. As the Queen's primary residence when not in Westminster, the guard presence was more subtle, but nonetheless very real.

Windsor Castle - Windsor, England - Copyright Andy Richards 2021 - All Rights Reserved

 I AM always impressed by their total focus when on duty.

Windsor Castle - Windsor, England - Copyright Andy Richards 2021 - All Rights Reserved

Windsor Castle -Windsor, England - Copyright Andy Richards 2021 - All Rights Reserved

 I KNOW that over the years, we will see many more guards and perhaps several more changing ceremonies as we continue to travel the world. Whenever possible, I will continue to photograph them.

Changing of The Guard Ceremony - Buckingham Palace - Westminster, England
Copyright Andy Richards 2021 - All Rights Reserved

Make Your Social Media Photos "Better"

THIS IS a topic I have discussed in the past. The original nature of the blog was to try to "help" new and less experienced photographers improve their approach. I still see these issues commonly, and there will always be new shooters, so I thought it was still a "fit." In the past I have blogged about some things to do to make your photos better ("better" of course, being subjective), especially for posting on social media. I have also blogged about some common things I see that make posted images just not work. I suppose I am mostly addressing more "serious" photographers here, often those who are participants in one of the many photography-oriented pages that seem to proliferate Facebook these days. I have downloaded several random images that have come up on my Facebook feed. I don't know any of the photographers, and it really doesn't matter. I will simply make some subjective observations about what I think makes a photo work, and what makes it not work. Maybe somebody will get something out of it. This is not in any way an attempt to assert a superior grasp, ability or vision on my part. None of the examples here are what I would characterize as "bad" photos. I do think, however, there are some thoughts and principles that could apply to improve them. More importantly, maybe some thoughts and principles that will help improve our future images.

Example 1

THE FIRST image here is something we see frequently on social media - surprisingly often on photo-dedicated pages. More often than not, these images are made with modern "smart phones." This is a nicely composed image, with pleasing, natural, contrasting colors and textures. That being said, there is nothing in the image in sharp focus. It has long been a truism that an out-of-focus image cannot be fixed after the fact (though I am less confident of that statement as each day goes by, given the advancement of digital processing). This is probably a better example than any I used in my prior blog, illustrating this weakness. At least I think it is a weakness. My eye needs to see something in the image in sharp focus. I constantly say that photography is art, and in that spirit, I will certainly allow for the possibility (though I doubt it) that the maker here may have purposely left the entire image out of focus. That may work for her/him. To me though, it just doesn't work. I could envision this photo with just parts of it in sharp focus (traditionally, probably the flowers in the foreground, leaving the barn out of focus - but the opposite might be an approach too. Or - maybe just the two tulips. A small aperture and wide-angle lens could also possibly allow for a fully sharp image from front to back, bringing the textures in the barn into the mix. Probably not my personal vision, but there are a lot of potential approaches to this image. But something has to be the focal point, and to do that, it must be in sharp focus.

Something has to be in focus

HOW DO we fix this? In my opinion, it can only be "fixed" in the camera with the original image. It is not something that any amount of post processing can remedy. Part of it is the photographer's "vision." When you make an image like this, I think it is important to think about what you are trying to show. In other words, "visualize" the final result. Then, this is an instance where photographic technique comes into play. My own visualization of this shot (at first blush, at least) would be to render the foreground flowers in as sharp focus as I possibly could. That means a couple things. Sharp focus, especially on close objects will be mostly a function of aperture and focal length. Knowing how those factors interact will be important to the outcome. A wide-angle lens will (generally) focus closer than a longer lens will. It will also produce a much deeper depth of field (how much of the image is sharp front to back, when correctly focused). A smaller aperture will produce similar results (greater depth of field). Either way, it is very important to understand your point of focus and how the camera and lens assists you with that. Before smart phone photographs became so ubiquitous, most of our cameras had some kind of focus point indicator (today, it is usually a square or rectangular bracket showing up on the viewing screen - and often turning a color - usually green or red - when focus has been achieved. It is possible on most modern smart phones to have this same indicator. That is critical, because all it is telling you is that the point in the image where you have the indicator is in focus. It doesn't guarantee other parts will be in focus. Cameras (and their operators) can be fooled about this. Sometimes the sensor will record the image, even though nothing is in focus.

THERE IS another factor, though, that often results in an out of focus image: movement. In a still image, any movement of either the camera or the subject will result in a blurry result. I think an image like this urges the use of a tripod. A solid base of support (usually a tripod) will take one of the most common factors yielding blurry results out of the equation. In my view, it is nearly impossible to record an image like this hand-held and have it be sharp. This is especially true with smart phones, because they are making some "average" calculations about exposure here. Subject movement (the other potential culprit) can generally only be dealt with by using very fast shutter speeds. Because exposure is a function of aperture and shutter speed, this isn't always possible. But usually, it can be accomplished with a good tripod and some patience.

Example 2

IN MY second example I see a couple things that could - in my view - improve this already nice image. The elements of a nice landscape composition are present. Nice colors and contrasts. As noted in my above comments, I might pay a bit more attention to the sharpness of the foreground. I have made images in the past where I have purposely blurred a foreground like this. It rarely works for me. In this case, it looks to me like the shooter was trying for a sharp image from front to back. In that case, I think the foreground lacks the critical sharpness I would like to see. In my view, the way to "fix" that is to shoot it at a smaller aperture in this case. And that likely means that we will need a tripod in order to get that result. Again, I find this type of scene (even with the rather bright light we see here) difficult to impossible to accomplish handheld. Unfortunately (yes, I am a tripod evangelist 😁) too many photographers today, too often take what I see as the lazy photographer's approach and shoot primarily handheld. I think the hype from certain quarters about stabilization built into cameras and lenses contributes to this failing. While that technology has certainly come lightyears forward, it is still not a substitute for a tripod when such use is possible. It appears to me a tripod would be possible here. I don't have camera info on any of these images - it is possible that they are made with smart phones, but based on the pages I see them on, I doubt it.

I am a tripod evangelist

ANOTHER THING that jumps out at me right away is that this image could benefit from some perspective correction. This as an issue with many (maybe most) images I see that are shot from a wider perspective (even from some very accomplished photographers). Looking very carefully at this image, it appears to me that the building is leaning slightly back off the hill. Some of this can be addressed in the initial shot. In this case, the higher the camera position, the less the perspective issue will show up. Easier said than done, especially given that it looks to me like the camera position was slightly downhill. To the extent possible, however, I would raise the camera up and try to tilt it down some. I shoot a lot of wider stuff in my travels and I find that most of the time, I still need to do some perspective correction in post-processing. Again, I have blogged about this specific issue in the past. My own experience tells me that the best tools for this process are found in the full version of Photoshop. Lightroom, ACR, and some of the other processing programs have tools that will work, but for real critical work, they seem too rudimentary to me. Nonetheless, if that is what you have, you should be able to make it work. In the case of this image, perspective correction was the first thing I worked on. It was mostly a combination of leveling and rotating the image. This can virtually all be done with the Light Room/ACR type tools. You can see the (albeit subtle) result here.

Example 2 - perspective corrected

A  SECOND thought I have about this image is the abundance of "dead space" in the top half of the image. Any substiantial expanse of plain sky or water is potentially a composition-killer. In this case the empty blue sky in the image takes up nearly 50% of the image. And it is essentially nothingness (If it were full of puffy white textured clouds, it might be an entirely different thing).  I might have tried to "crop" this image in the field, but altogether too often we are working with the given aspect ratio of the sensor, and the characteristics of the lens being used. That is one of the reasons I like to have more megapixels when I can. It gives me more digital "headroom" to crop without losing image quality. These days, I often shoot keeping in mind that I am likely to crop (and perspective correct) in post-processing. Both mean leaving "space" in the image for such adjustments (and being aware of what the adjustments will do with the image in question). Sometimes I mess up. I recently made an image of an ancient Japanese Castle gate and didn't leave enough room in the image at the corners of the roof. Today's tool set is amazing. Though not the preferred way, I used the new AI-generate in Photoshop to create some space and the corner of the roof. It worked (mostly). Another "AI" thing you can do (and this one has really been around for years, but more recently, the software processing improvements have made it much easier) replace the plain blue sky with a more pleasing sky. I do that sometimes. More often, though, I crop. My suggested crop is shown below. There is no "right or wrong" crop here.

Example 2 - cropped sky

Example 2 - digitally "sharpened"

AS I said above, You cannot really make an unsharp image sharp. Sometimes you can employ digital techniques to increase the appearance of sharpness. In the final example 2 image below, I did that using a combination of contrast, brightness and a third-party (NIK Viveza2) adjustment called "structure" (a bit like "texture" in ACR). It cannot begin to replace what a smaller aperture, tripod supported shot would have done with the foreground. But maybe it suggests how that might look and why it is appealing.

Example 3

THE CHURCH (or meeting hall) is interesting. It has many elements of a nice image. One of the great things about our art is that we can have different approaches to all the various aspects of it. In this image, I will suggest a couple things I would personally do differently. That doesn't make them right. Nor does it imply that the photographer's original image is in any way "wrong." It is just a matter of how we approach things. Before we do that, however, there is one glaring issue that I think very much detracts from the photo. Anyone else see it? The tree-blocked steeple means for me that this otherwise nice image just doesn't work. We have this huge, bare tree in front of the church (or meeting house). Maybe if it was in full foliage, the dynamics would change (especially colorful fall foliage). But here my mind just keeps going to the fact that the steeple is essentially completely blocked out by that big, dead tree. In the field, I would have looked for a viewpoint where I could get the complete building in the photo. It may be a wide-angle lens (realizing that there would be significant perspective issues there). Maybe it would be a different angle to shoot the building. Along that same line of thought, the subject comes awfully close to being a dead-center composition. While still subjective, one of my early lessons in critiques of my work was to avoid what I now call the "bullseye" composition. It is pretty natural if you think about it. Most lens focusing points and composition aids start centered in the frame and kind of subconsciously lead us to positioning our subject right in that center. In many instances that creates a much less dynamic composition. For simplicity's sake, I usually suggest looking at all landscape shots with the "rule of thirds" in mind, placing objects of interest in a point in the image that makes a more dynamic (and therefore interesting) composition. I don't know for sure, buy maybe trying to find an angle that frees the steeple from the tree might give us that result.

the tree-blocked steeple means for me that this otherwise nice image just doesn't work

ASSUMING WE are able to find a better angle, there are a few subjective items I would address. There is really a lot going on here in the scene. Maybe trying to highlight some of them would actually detract from the building and the nice light falling on it. I don't know. I just know I would try some different thoughts here. I think there is a lot of potential to bring out details in this image that might make it more interesting. It is important, I think, to reiterate that this is my own subjective viewpoint. As you do bring out details surrounding the main subject, you run the risk of detracting from that main subject (and its importance). Shadow and darkness can make an awfully good cloak for undesired details. On the other hand, I like the flowers surrounding the church. I don't think they will detract. I also think that bringing up the shadows in the trees will add a touch of depth and realism to the image. In the old days of film, trying to cover contrast between the shadows and the relatively bright sky was very much a compromise. Today, the substantially increased latitude digital recording and the ability to work with areas within the photograph gives us is a really nice luxury, allowing much more "playing" with exposures. The sharp observer will notice one other change I made. I didn't like the strip of asphalt at the bottom of the image. While it migh have been left there to suggest the road in front of the scene, I don't think it worked. I think it is distracting. My "take" has it cropped completely out of the frame.

Example 3 - my adjustments

THIS LAST one is an example of an already really spectacular image. Everything comes together here: right time, right place. So why do I feature it? It is an example of "I like it, but I would do it differently."

Example 4

WHEN I saw this image, I immediately hit the "like" button. One of the comments was: "all the right parameters." I don't know why, but the comment struck me. I disagreed. As much as I like the image - and I really do - I wanted to dig into those shadow areas and see just a little bit of detail in there. My adjustment is ever-so-slight, but to my eye (and I once again emphasize, it is my subjective eye) it small improvement. Unlike some of the other highlighted images, this one is purely subjective on my part.

Example 4 - my adjustments

HOPEFULLY, THIS post will be read and accepted in the spirit offered. I still (always will) remember my very first photography mentor. He is still shooting today and we have not only reconnected, but have remained friends over the many years since I was first inspired to pick up the camera. Extremely proud of one of my early "successes," I took it to him for his commentary (probably seeking approval more than anything). What he said to me has resonated to this day: "do you want me to say nice things about it, or do you want an honest critique?" It doesn't take a genius of inductive reasoning to realize that he didn't say: "wow, perfect photo!" 😁 He complimented me on getting certain things right, like focus and exposure. He even liked the overall composition. But the photograph lacked a certain "something" (in this case, a well-defined and interesting subject) that would differentiate it from a good photo to just a nice picture. The point here, really, is that good photographs need to be thought about, in many cases planned (though the planning is often done in seconds and over time becomes reflexive) and requires a thorough knowledge of optics, exposure and your gear. That takes homework. And practice. My takeaway from that day and from this post is that there is always something we can improve upon.