Preface
This is not meant to be contentious article but it will probably result in the wrath of many. It’s for this reason that I would like to make the following clear:
What it is not:
• It’s not intended to be an APSC vs Full Frame argument from the perspective of trying to prove that APSC is better than Full Frame. Many may see it this as the purpose of the article, but it’s not. When looking at Medium Format vs Full Frame vs APSC, the argument of “what is better” comes down to a number of requirements including purpose and budget. In the absence of budget, one could argue that having all 3 would be the right outcome, but very few people have live in an environment where budget is not a constraint.
What it is:
• It is an article to show what the gap is between full frame and APSC and how small it is.
• It is intended to show that the argument that APSC is amateur only is one that is only dictated by some manufacturers.
• It’s intended to show that full frame is no longer the required long term progression that it once was.
• It is intended to show that very few “non-professional” photographers “need” full frame, it’s important to differentiate between “want” and “need”.

Introduction
The whole APSC vs Full Frame debate can get fairly heated. I’ve seen more than a fair share of topics shut down on forums as a result. A lot of the discussions between APSC and Full Frame tend to stem from a mirrorless vs DSLR debate where the story goes a little like this:
1. The mirrorless vs DSLR debate starts on a random forum in a galaxy far far away
2. Both sides goes through various arguments that I won’t bother going through because they are largely pointless and repetitive.
3. Eventually the argument of camera size will come up, whereupon the DSLR fans state that mirrorless isn’t that small because glass is the same size if they both full frame.
4. Someone comments that many mirrorless systems offer professional outcomes with APSC and then vast majority of full frame users spend the next 500,000 posts coming up with every conceivable reason why they and every other photographer on the planet needs full frame and why none of them could ever live without full frame.
Sound familiar?
Now, in their defence they might feel they “need” all of that, but I believe in most cases, that need is based on a false perception created by the primary DSLR vendors, namely Canikon. You “need” a car to get to work if there is no public transport. You may need want a luxury car so your family is comfortable and safe, but you don’t “need” a Bentley SUV when a BMW X5 or even a Range Rover will give you the same outcome at considerably less.
Let’s be clear, there are many good photographers who are not constrained by APSC. They are far better than me, better than most full frame users, and better than 95% of the users on forums who feel that APSC is such a hindrance that they could not survive in a world of only APSC. I don’t believe what these good APSC photographers are doing is magical. They are extremely talented, but I also believe that if these talented photographers have reached this point without being constrained by APSC, there are very few people these days who can claim they are actually “constrained” by APSC. APSC image quality is well beyond the image quality of previously generation full frame cameras and professionals then weren’t constrained, but somehow every amateur photographer feels they are constrained by the image quality of APSC.
These anally retentive IQ hunters spend hours examining their images at 100% and making sure they have the sharpest possible camera and lens combinations, without realising that there is a limit to what you need to create a good photo. Very few photos are blown up to a size where IQ becomes relevant. Obviously no one is arguing that every user should go out and buy a $200 kit lens, but the reality is not every photographer “needs” $7000 sharpness of a top of the range Zeiss to create really great photos.

The history
I blame the current need to move to full frame on the propaganda machine from big DSLR manufacturers. Thanks to them, we’ve grown up our entire (digital) lives believing that good photographers “need” full frame cameras and only amateurs use APSC. It might have been valid at some point, but they’ve done a good enough job to keep the propaganda where it is today. This approach is reflected in their glass and their bodies. As a general rule, all the APSC glass is cheaper non-professional glass and all the more expensive glass is full frame. Yes, you can use the full frame glass on APSC, an argument we hear time and time again, but the cost of using full frame glass on an APSC camera means that you are paying for something you don’t fully benefit from.
Too many amateurs are tied to chasing the technology behind cameras rather than taking photos. It’s the mistaken belief that their gear is hindering them more than their lack of skill. If they spent as much time taking photographs or studying techniques as they did on forums, the impact on their photography would be greater. That aside, ignoring the issues with manufacturers, let’s go back to some of the major differences between APSC and Full Frame. I’ve tried to use the metrics from the same manufacturers to avoid issues of people complaining about which ISO standards have been used.

Low light
As it stands right now, I would estimate the “real” difference between comparably priced camera sensors is about 0.5 to 1.5 stops at any given point in time. Depending on the age of the camera and the purpose of the sensor this may be different, and it may change as new sensors come out, but that is roughly where I see it. Fortunately someone has already provided the facilities to do some comparisons so I pulled off some examples to show the differences. To make a fair comparison, I have pulled off two images from the same manufacturer because it removes the issue (or argument) of ISO methods used, sensor noise reduction etc.
The following is a comparison using the comparison tool at DPreviewshowing one stop difference between the sensors.

If you start moving to the high end DSLRS like the 1D and D5, that may improve, but I think that has more to do with the amount spent on the sensor development than the sensor size. I.e. By nature of the amount invested in the sensor development and the cost of the sensor, the sensor found in a $7000 full frame should be far better than one found in a $2000 APSC camera and the only fair comparison would be to compare a $7000 full frame with a $7000 APSC, if one existed. How important that one stop is, is a different story.
Given there are a multitude of professional photographers who feel they don’t need to upgrade the moment a new camera comes out, and the multitude of amateurs who feel they do, I would argue 10% of photographers “need” it, most of which reside in the professional camp, not the enthusiast/amateur camp. We want it, we would like it, but we don’t need it. It’s not the showstopper people make it out to be because we aren’t printing A0 prints at ISO12800. What I also believe is that low light capability steers amateurs away from the things they should be learning to make themselves better photographers.
I’ve only seen a handful of really spectacular photos shot at ISO12,800 where APSC might have been a problem, but I have seen many photographs shot with off camera flash that look spectacular in environments where ISO12800 would have looked terrible. This is because shooting at f/5.6 or f8 which results in much sharper photos, catch lights in the eyes and you can make the backgrounds look far less distracting by taking them out of the equation completely. Rather than focussing on 1 stop of low light and spending an extra $2000 on glass, you’d probably be better off getting a decent strobe and softbox (with a battery) and learning to shoot with lights. Worried about a child? Get your flash off camera with a small softbox and again your results will be far better.

DOF (Depth of Field)
This is one that comes up time and time again. I need shallow DOF, DOF is critical, if I don’t have DOF I’m going to die, the solution to world peace is about shallow camera DOF. So, yes, I get they need DOF. But do they need more DOF than offered in APSC currently? And more so, how many of these photographers actually know how to use DOF? And not just opening the aperture up and shoot everything wide open, like someone who just bought a new 1.4 portrait lens and spends the first week shooting everything at 1.4. How often do you see someone who uses a 70-200 where you’d be mistake for thinking their camera had been locked in aperture priority at f/2.8 it’s entire life because they haven’t learnt to shoot anything except a landscape at beyond f/2.8, unless they suddenly find themselves at a point where the camera is over exposing on a bright day because the shutter can’t go high enough?
Don’t get me wrong, I’ve seen incredible photos shot at f/1.4 and f/2.8 by some very good photographers. I’ve seen beautiful shots looking down orchards with a shallow DOF on a 105 f/1.4, and I have no doubt that there are a lot of photographers that do legitimately need and know how to use shallow DOF, but they are minority rather than the majority, the balance lug around 70-200 f/2.8’s and 85 f/1.4’s hoping it’s somehow going to make them a better photographer. And let’s be realistic. The opportunity to take photos down an line of trees with a strobe, child or a beautiful model are fairly limited. People would like to believe they have those, but the amount of times they actually get to do them would be close on zero.
The second issue is whether you need wide open apertures on a zoom permanently. There are two reasons to shoot at f/2.8 zoom, low light and DOF, and I suspect the majority of people are using it for light rather than DOF. Does your 70-200 zoom need to be shot at f/2.8 permanently for shallow DOF through the entire range? Not likely, it creates an environment where you photos become boring because they have the same look. In most cases a good prime will be better quality, sharper and provide less distortion than a zoom so whilst the 70-200 might be convenient, it’s not the best and a good prime will often do a better job.
Aside from what I have mentioned, you also have the clan who “need” full frame for shallow DOF, but can’t actually afford to buy decent lenses so they buy a full frame, and load it up with 70-200 f/4’s and 24-120 f/4’s? This is very little value for you to be there other than future proofing (which is a legacy of the marketing of the DSLR maufacturers), but ultimately more than half of the buyers never end up buying the expensive stuff because it continues to be outside of their budget.
Now, before you complain, if you’re a professional photographer, be wedding, portrait or whatever speciality you do, I get that you really do need shallow DOF and I get that you know how to use DOF, but conversely, I also know of incredible wedding and portrait photographers who use only primes. What I don’t get is how amateurs feel they need it when they don’t know how to use it.
I will say there is also a negative to DOF. If you are shooting in low light with a full frame, using too wide an aperture can also have a negative effect, the DOF can be too shallow and you can’t shoot at a narrow aperture because the light doesn’t allow for it.

FOV (Field of view)
Field of view is not a problem with APSC, the manufacturers are. What I mean by this is good APSC wide angle lenses exist, and correct zoom ranges exist, the issue is that some manufacturers have chosen to demarcate APSC as amateur, and in doing so the have also imposed restrictions on APSC glass. Fuji make APSC zoom ranges, so do Sigma. Canikon don’t.
IQ (Image Quality)
IQ is an interesting one, because in theory they are right. I say in theory, because IQ comes at a cost, and I don’t believe it’s a cost that everyone can afford if they knew the real cost. It’s also a question of why this level of IQ is important and where the limit of suitable IQ is. It’s a little like comparing an $2000 APSC camera to a to a $15,000 MF camera. If you want to compare apples with apples, you have to at least work with some constraints, namely cost because inevitably, budget is not an open constraint for most people.
For example, if you compare a X-T2 with a 16-55 to a D750 and a 24-70 f/2.8, the D750 will win on IQ. Will you notice on a picture blown up to smaller than A1, probably not. But even so, that isn’t exactly a fair comparison, because the Nikon 24-70 is nearly twice the price of the Fuji 16-55, so if you do a closer comparison of the D750 with a 24-120 which is comparatively priced, the Fuji is likely to win for a couple of reasons:
1. The sharpness of a good APSC lens is likely to be better than the sharpness of a mediocre full frame lens.
2. The f4 on the 24-120 means you have lost you one stop of light advantage you had over the APSC camera so that isn’t relevant.
3. The DOF is exactly the same.
4. The construction on a premium APSC lens is likely to be better than a mediocre full frame lens, because it’s premium vs non-premium and APSC has a lower cost to manufacture.
If you took the best of both worlds, the full frame would win, but then you could also need to consider that every time you increase the budget, the APSC would allow for an additional lens. I.e. For the cost of an a 70-200, you could have the 50-140 and a prime like a 56 f/1.2 or 90 f/2. If you factor in the 24-70, you could have a 16-55 and a 10-24 so you could buy the trifecta and a good portrait prime for the cost of the 24-70 and 70-200 and have a range from 15-200 covered with pro glass. Add the cost of the 14-24 and sudden you can add the trinity of Fujicrons (23/35/50) along with a macro and have some change left over. And conversely, for the cost of a D750, 24-70 and 70-200, you would only be able to buy a Fujifilm GFX with no lenses. Cost is a always a factor and the question is where does the compromise sit? Now that may seem like a simple question of “get the best that you can afford” but sometimes the answer is not that simple. The question you also have to ask is “Will the GFX allow you to take better photos than you could with Full Frame or APSC” and for most photographers, I would say the answer is no.
The next thing you have to consider is whether you will actually see the difference. Are you worrying about IQ for the sake of it, it will it realistically impact your photos if you took the same photo at the same focal length? I challenge someone to show me two photos where you can see the IQ difference when printed to a reasonable size. Yes, you can see the difference between cheap glass and pro glass, but pro APSC vs pro Full Frame is a different story. If you printed two images to an A4 size, would you actually be able to see the difference? Even if you print to A0, it’s unlikely you would see the difference unless you walked about close which is hardly the way people view images.

Summary
I’ve tried to cover everything I can so if I missed anything, feel free to let me know.
So in summary, what is the difference? To do that you have to ask yourself a couple of questions:
1. Can I afford the cost of good ($2,000+) full frame glass and am I prepared to pay that on an ongoing basis? If you can’t, or you are buying f4 lenses, you’re wasting your time on full frame. You would have better quality glass with better image outcomes with APSC.
2. Is 1-1.5 stops of light worth double the price of my lenses? I.e. if you want to spend $5,000 on camera gear, would you spend $10,000 for an extra stop and a half (worst case) of low light? If not, you would be better off with APSC.
3. Do you need paper thin DOF on an entire zoom range and is it worth paying twice the price rather than using a prime for the odd occasion you need shallower DOF? Again, consider the comparison of 2 lenses vs 4, or 4 lenses vs 8.
4. Do you actually know how to take advantage of the DOF of your full frame lenses? I can’t answer that question but this is one where you probably need to leave your ego at home and think realistically?
5. And finally, probably the hardest question to ask is whether your gear really the limiting factor to your photography? Or whether the difference would be better invested in some photography workshops.
This article was really helpful for me as I decide which camera system to move towards. Thank you so much.
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Thanks. Glad it helped. 🙂
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Thank you for this article! Im currently trying to decide which mirrorless should I buy, and now I probably know I dont need full-frame :)) Cheers!
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After reading this I’m switching to full frame from apsc
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