Why I Am Staying with APS-C

After a many year hiatus, I returned to photography as an avocation. In years past, I had been a semi-pro, using primarily Leica gear and film, of course at full frame. In those days the only significant half frame camera was the Olympus, which in spite of the smaller but more useful format gave a good account of itself. It did not hurt that Olympus glass was at that time some of the best coming from Japan, especially for snappy contrast.

In any case, I got burned out. I was working in the photographic hardware manufacturing industry and got to the point that enough was enough, and I put aside the cameras.

Fast forward 35 years… Four years ago, I had a smallish but decent point-and-shoot camera with a 6X zoom lens and an optical viewfinder. Now largely retired, my wife and I took a tour of Scotland, especially the Highlands and the Western Isles. The incredible scenery renewed my interest in scenic landscapes, and I took a lot of pictures. The images looked great in the viewfinder and I could not wait to see them once I got home.

I was bitterly disappointed. Many of the pictures were fine, but some, particularly at wider angles, simply were not sharp, especially into the corners. I had been counting on that in framing the shots, but it simply wasn’t there. In retrospect, I most certainly should have known better, having had a lot of experience in lenses back in the day.

Long story short, my interest in photography as an avocation was renewed again, and I started looking for better equipment. There was no question I would go digital; chemical darkroom work in my earlier days was never something I enjoyed. I wanted interchangeable lenses. I wanted a fairly compact camera. I was planning to get my feet wet so I did not want to spend a fortune getting started. I looked at mirrorless — that seemed ideal for me.

At the time I bought my APS-C camera, full frame mirrorless cameras were also available. I have always been a sharpness freak, and the Sony a7R III really caught my eye in particular. But I quickly figured out that I would be looking at well north of $4,000 in a big hurry for a usable set-up. That did not quite meet my definition of getting my feet wet.

After a lot of study, I ordered the Sony A6000 and two additional lenses (a 30mm and a 60mm Sigma). The results from the new package really blew me away. The sharpness and picture quality were clearly far superior to my pictures from yesteryear. I was — and remain — delighted with the capability of these new tools.

Note: This article is NOT about Sony cameras, though I will readily confess to being something of a Sony fanboy. What this is about my decision to stay with the APS-C format and why I do not plan to migrate to full frame or even to medium format. Also, please note, this is not an argument in favor of mirrorless cameras — my comments here apply equally to DSLR and MILCs.

In any case, I soon discovered that having escaped the chemical darkroom, for best results I would need to upgrade my computer package, which I did. Also, I collected several different software packages, some of which are today unused while others are important tools for me. Some were free; others were not.

I took a course at the local junior college, “An Introduction to Digital Photography,” which turned out to be a real help in many ways. I joined the local camera club. My wife and I took several trips which offered me new vistas for photographs. I was definitely hooked again.

My primary interests were and are landscapes, cloudscapes, and travel shots. I don’t do people, except for family. I do not video at all. I don’t do sports photography and only incidental wildlife. Street shots or low light shots are not my thing. Although I did get a few of my shots printed and framed, the majority of those I want others to see go on my 50″ TV, or are sent over the internet, or even mailed compact disks where bandwidth is an issue.

I was slowly upgrading my capabilities and skills on many fronts. My pictures were getting better. I read magazine articles, I watched YouTube videos. It should be of little surprise that I began to consider a full frame camera.

What would I gain by “upgrading” to a full-frame camera? The benefits usually promoted are better sharpness and resolution, improved low light performance, and less noise at elevated ISOs. Additionally, most newer full frame cameras offer in-camera image stabilization, though that is also available on some APS-C cameras. Certainly there are other benefits, such as video with no overheating. But, far and away, though often not stated, the biggest real benefit of full frame is significantly better bokeh. More on this later.

So how do these aspects affect me? OK. I don’t do video at all. So nothing for me there. And interestingly, all except a few of the top line full frame cameras offer resolution very close to the 24 megapixels my A6000 offers. That being the case, it is hard for me to imagine that 20×30″ prints would be significantly better from a full frame camera unless I went to the rather expensive high-end FF machines, with which I could reasonably hope for about a 20-25% improvement in sharpness; certainly discernible in close inspection but for most uses barely noticeable. And this improvement can only fully realized if the lenses used are capable of supporting the resolution of the sensor. Also, there are recently available serious software tools that will improve the results of my system or any system. More on that later, too.

A consideration of lenses was another subject I gave some serious thought to. I love lenses and have tried a lot of them. For the same angle of view, a FF lens needs to be 50% longer in focal length compared to a lens for APS-C. So, for example, a 30mm lens for an APS-C camera will give the same image as a 45mm lens on a FF camera.

I own three lenses that are my “go to” glass. These are all lenses designed for APS-C, all are autofocus, and all of them give me excellent results. They are a Sigma 30mm f/1.4 DC DN lens, a Sigma 60mm f/2.8 EX DN, and a Sony 18-135mm f/3.5-5.6 zoom, designed for APS-C. None of these lenses have adequate coverage for FF.

Lenses designed to cover an APS-C format, can, again all things being equal, offer resolution every bit as good as an equivalent lens (adjusted for focal length correction) for full frame, and almost always at a rather lower cost. The lens designer has fewer trade-offs to deal with for the APS-C lens. Covering the smaller format is technically easier, especially with shorter focal length lenses, and again for the larger aperture lenses. Further, it is possible to make excellent zooms with greater focal length zoom ratios for the smaller format, such as the excellent Sony 18-135mm or the Sigma 18-300 zoom for Sony APS-C.

Many of the FF cameras do offer in-camera image stabilization. Now, this is something that really could be useful to me. At my age, I simply can not hold a camera really steady anywhere close to what I used to be capable of. I have to confess I had real doubts about how well image stabilization would work. But I do own one lens with built-in “OSS” — Sony’s acronym for “Optical Steady Shot” — or image stabilization, which they claim is good for a 5 stop improvement in shutter speed for a given exposure. The results with that lens surely chased away my doubts — I found myself getting sharp handheld pictures at a 15th of a second! Admittedly, that was at the short end of the lens zoom range.

But I have no other lenses that offer image stabilization. So having it built into the camera would surely be a benefit.

System resolution has always been the major criterion driving my equipment goals. To this end, there are essentially two positive components: sensor resolution and lens resolution. The precise mathematics of the relationship elude me, but suffice to say that doubling the resolution of the sensor does NOT double the system resolution, but it will give it a nice leg up; something approaching a 50% gain — again, IF the lens is capable of supporting the increased sensor resolution.

Doubling of sensor resolution is a feat of technological prowess, but seems to be something being achieved by several major manufacturers. It certainly seems ultimate limits have not been reached. Doubling the resolution of a lens is hardly a trivial achievement — it is very difficult. Lenses have benefited greatly over the years from new glasses becoming available, ever improved computer design programs and, significantly, the ability to manufacture optical-quality aspheric lenses in quantity. That said, a 10% improvement in the resolution of a flagship lens would be cause for celebration for the designer, let alone doubling resolution.

In any case, while I have no definitive numbers to back this up, my feeling is that the practical system resolution of photographic systems available to the general public has improved by a factor of 3 to 4 over the last 50 years. Of course, this is a simplistic statement, in that it ignores major improvements in other areas, such as improved color, post-processing capabilities (even including very real sharpening using AI), quality zoom lenses, video, lens stabilization, etc, not to mention astounding increases in usable ISO.

While we generally do everything we reasonably can to improve the sharpness of our pictures, there are plenty of things that will drag system resolution down. Focus accuracy is a biggy, as is camera shake. Lens filters and dirty lenses are of no help.

OK. I accept as a given that a FF camera, all else being equal, is going to be “better” than an APS-C camera. But, with a well-designed quality APS-C lens and good technique, it will be very hard to discern a difference even in a large print or on-screen magnification to the pixel level.

The FF camera will certainly generate “more bokeh”, or out-of-focus backgrounds. At the same aperture and with the lens focal lengths corrected (lengthened) to maintain the same field of view, the FF setup will always have rather less depth of field. For many photographers, this is the over-riding reason for going to FF. But not for me!

(A tip here for APS-C mirrorless users: if you do want a capability for portraiture with bokeh, look for a 58mm f/1.4 lens from the film days, add the appropriate adapter, and you have the equivalent of an 85 mm lens for FF. Yes, you have to manually focus, but you will get good separation from the background. You should be able to get a decent one for $50 or less on eBay or Craigslist, plus $10 to $15 for the adapter for your camera.)

I mentioned earlier that software can enhance the apparent resolution and sharpness of an APS-C camera, which it certainly can, but of course, it can also do the same for FF cameras. Here I am not talking about the sharpening tools of conventional post-processing programs, but instead some rather revolutionary AI programs from Topaz Labs. These programs are strictly for still photographers unless you have time available on a super-computer.

I strongly urge you to take a look at this video:

The presentation is a little slow at first, but then the creator really gets into nuts and bolts that will make your jaw drop.

So. Time for the executive summary:

What are the advantages of APS-C?

Cost: It is very possible to get an excellent outfit for well under $1,000, buying new. A significant improvement in terms of sharpness by going to high-resolution full frame will easily reach and exceed $5,000.

Weight: The APS-C outfit will be significantly lighter than a comparable full frame outfit; little more than half in most cases.

Quality: Careful selection of equipment and software will give a package of making excellent 20X30″ (50X75 cm) prints or images that are extremely sharp on a 50″ (1.27 meters) TV screen. All else being equal, the FF equivalent will indeed be better, but only by a small margin.

What are the advantages of upgrading to a full frame outfit?

Low Light: Significantly improved low light performance at high ISO.

Bokeh: Better bokeh.

Technical: Much reduced heating issues in videography.

Image Quality: Present high-end cameras offer a gain in resolution and sharpness.

Lenses: A larger selection of lenses available for most cameras.

Full confession here: I did upgrade! I went to a Sony a6500. It’s APS-C but with weather sealing and image stabilization. I still don’t plan to go FF.


About the author: Bob Locher certainly makes no claim to being a great photographer; rather, he considers himself to not be a very good one. He is not much of a speaker either, and does not have his own YouTube Channel, nor does he do Photographic Tours. But, he has been in the photographic hardware industry most of his life, fancies himself as something of a writer, has opinions and is not afraid to express them. He loves photography, values technical quality and is indeed a pixel-peeper. The opinions expressed in this article are solely those of the author. Locher has written over 50 magazine articles as well as two books. You can find more of his work and writing on his website.

Discussion