Full Frame vs. DX Cameras
Why I’m sticking with DX (for the moment)…
Which camera to use? Every photographer faces that question at some point, and generally we try to buy the best gear we can afford. I’ve gone through numerous digital cameras, and at present own ten different cameras of all shapes and sizes. Each has its own advantages and disadvantages, but I have fun with all of them. But when it comes to my “signature” style of saturated color night photography and light painting, I only use one camera. At the time I bought it, my Nikon D300 provided me with the best balance of features and image quality that I could afford. I prefer shooting digital over film for night work for several reasons (which I will reserve for a different post), but suffice to say the flexibility in white balance/color correction, exposure latitude, and not having to be stuck with an entire roll of one type of film keeps me shooting digital at night.
Now, with the introduction of the D700, it has become financially viable for me to buy into a full-frame (35mm sensor) DSLR system. I (like most digital SLR owners) have been using a “cropped sensor” or DX camera. The D300 has, for all intents and purposes, the same body as the D700. It has the same number of megapixels. But the D700 offers those inherent full-frame advantages that people are willing to pay so much for: lower noise at high ISOs, shallower depth of field, a larger viewfinder, wider angle lenses… I must admit, it’s extremely tempting.
However, I’ve decided to hold off at least until we see the hypothetical “D700x”, a full frame camera that packs 24+ megapixels like the new D3X. It’s not a purely financial decision, either. Upon careful consideration I found that for my style of shooting, the benefits of FX are less applicable, and sometimes even counter-productive, for my specific type of shooting.
Less Noise at High ISOs
Now, you’d think a guy who spends most of his time shooting at night would place a high premium on a camera with great low light sensitivity, right? Well, for my kind of work, it’s a moot point - I only shoot at the “native” ISO of the camera I am using. With the D300 and D700, that’s ISO 200. Having the ability to shoot relatively clean files at ISO 6400 might be nice, but I would NEVER use a high ISO for the specific style of night work that I do. I want files that print 20"x30" with no visible noise. It may be true that the D700 gives slightly cleaner results at 200 as well, I have no idea. But the files from my D300 appear totally noiseless in 20x30 prints, so it is of no practical value to me at all.
100% crop of a D300 shot at ISO 200
Larger Viewfinder
The D700 gets a big point in my book for having a larger viewfinder than the D300. Framing compositions at night is challenging, and generally the bigger and brighter the viewfinder, the better. My ability to get compositions right without cropping went up steeply after upgrading from a D70, with a tiny, dark finder to my D300. However, the D700 has a hidden disadvantage here as well - while the finder is a bit bigger, the accuracy takes a hit. The D300 finder has higher magnification and 100% coverage - that is, what you see is exactly what you get. The D700, however, has only 96% coverage and slightly lower magnification. That means I risk having to crop more to “fix” compositions that are slightly off due to the inaccuracies of the finder. On balance, not a true benefit for the way I work.
D300, Nikkor 85mm f/1.8D lens
Wider Angle Lenses
It’s a fact that landscape photographers love wide angle. And on FX, a lens of a given focal length “acts” wider. For instance, a 17mm lens on FX is really effing wide, but on a DX crop camera it is only medium wide. Also, wider angles are possible with FX - there is no DX equivalent of the Nikon 14-24mm f/2.8, or the Sigma 12mm zoom. You would need an 8mm rectilinear lens to equal the 12mm field of view on DX, and such a beast sadly doesn’t exist. However, for my style of working, a 12mm DX lens (which would be similar in angle of view to an 18mm lens on FX) is plenty wide enough. I’ve actually found myself using longer lenses more and more lately - much of my new work has been shot using a Nikkor 85mm lens. I’m in the market for a longer prime as well, probably a 135mm Nikkor AIS lens. On FX these lenses would lose some of their effective reach, and I would have to step up to longer, more expensive glass to make up the difference.
D300, Nikkor 85mm f/1.8D lens
Less Depth of Field
This is the big one for me. FX cameras have less depth of field for a given viewing angle and f/stop. This can be a great thing when you want to isolate detail, for instance in portraiture or food photography. But for landscape, more DOF is almost always better. The practical result of a switch to full frame for me would be that I would have to use smaller f/stops to get the entire scene in acceptable focus. Probably up to a whole stop smaller. That means instead of shooting 5 minutes at f/8, I’d be shooting 10 minutes at f/16 f/11. Not a huge deal, but then add on in-camera noise reduction, which doubles the exposure, and I’ll be spending 20 minutes per shot. That would cut my productivity for any given time spent shooting in half. True, working slowly can help you make better, more considered decisions, but trust me, night shooting is slow enough as it is ;)
Almost infinite depth of field at f/6.7
The one thing that full frame cameras could provide me with that I really do want is higher pixel counts. I like to print LARGE - I’ve got a trio of 20"x30" prints going up in a gallery in Brooklyn next month, and had a 24"x36" print in my last show. I am one of those users who really can use all the resolution they can get. The 24mp sensor in the D3X would give me a solid, real-world benefit that would be applicable to my style of shooting - but sadly $8k for a camera is a bit out of my reach at the moment. So I’ll wait for the hypothetical “D700x” or “D800” and enjoy my very nice professional tools in the meantime.
Hey Toby
Interesting piece. As a night photographer who has recently upgraded to the D700 (from the D200) let me give you my 2c worth.
First of all, I wouldn’t disagree with your conclusion at all. If I had a D300, I probably would wait. My upgrade strategy has been to leap frog upgrades (thats why I stuck with the D200 and didn’t go to the D300).
However now that I have made the leap from DX to FX format I do love it.
Specifically for night photography the low ISO is more important that I would have thought for a couple of reasons
1) Extend your night shooting - It means that instead of just waiting for really bright moonlit nights, I can go out on half moon or even cresent moon lighting conditions and not spend eternitys getting exposures.
2) Sometimes the effect you want relies on you not exposing for 3, 4 or 6 minutes. If the wind is howling and the clouds are low, perhaps 1 min of exposure is the optimum to create just the right cloud streaking look etc. By being able to dial up to 400 or 800 iso without any significant noise impact, I now have more exposure latitude. (I would NEVER shoot off iso200 on my D200… but it’s nice to have the choice)
The artificial horizon is nice to assist with night composition, but I do agree with your comment about 96% crop vf.
If I had a D300… I’d probably keep it (unless I was rolling in dough).... however now that I have the D700… I love it.
Brent
Brent Pearson on Feb 26 at 10:04 PM
That’s pretty much how I think about it. I would have held off on the D300 if I had seen the D700 coming, but I definitely didn’t expect it, at least not so soon ;)
I agree with your point about the value of flexibility thanks to the high ISO capability, but as for my personal shooting, I’ve never run into a situation where I needed a shorter exposure than I could get without bumping the ISO. Which is very different than saying if I had the capability, I wouldn’t find ways of using it!
Anyway, this is just my cost/benefit analysis, and I will definitely be going full frame once it offers a little more bang for the buck.
burnblue on Feb 26 at 10:43 PM
BTW, you broke my comment design! Now I have to make the background graphic taller! ;)
burnblue on Feb 26 at 10:45 PM
Toby
Sorry I broke your comment design. I will keep comments to a minimum in future.
;-)
BP
Brent on Feb 28 at 03:28 AM
Har har ;)
I needed an excuse to fix it, now I just need a few free minutes!
Toby on Mar 08 at 10:46 PM
Hi, I would just like to correct you on one point in your write-up.....
DOF is dependent on 3 factors with sensor size NOT being one of them.
The three factors that determine your DOF are;
-F stop
-Lens length (mm)
-Distance to object (or distance focused at to object)
The only thing that DOES change amonst formats (DX to FX) is FOV or your field of view, meaning you will have a wider frame.
Here’s a simple way to demonstrate this.....
Take a full frame or FX lens and sticking it on a DX body. Keep the focal length the same, f stop and distance focused/distance to object the same and crop your FX image to match the FOV of your DX image......
You will find that the DOF is identical, the only thing that will lead you to believe otherwise is if you do not crop the full frame image and were to judge by eye....
Here is where perceived DOF comes into play when shooting on a larger sensor. A number of attributes can play into this “perceived shallower dof” mainly being a larger area that is out of focus behind your subject, and FX format lens may have a more contrasty coating than a DX lens thus adding to that perception as well.
Thanks for the write up. =)
Alexander Nikishin on Apr 04 at 09:20 PM
Alexander,
You are correct in your points above, but it is irrelevant. This sentence demonstrates my point: “You will find that the DOF is identical, the only thing that will lead you to believe otherwise is if you do not crop the full frame image and were to judge by eye.... “
See, after shelling out the cash for an FX system, I wouldn’t crop the full frame image and I would definitely judge by eye.
Photographers select a lens for the angle of view it gives. I wouldn’t try to shoot ultrawide landscapes on DX with an 18mm lens, even though that 18mm lens would be ultrawide on FX. I would select a 12mm lens instead. This means shooting a given angle of view will yield more depth of field on DX than FX.
Look at it this way - like you said, “the three factors determining DOF are
-F stop
-Lens length (mm)
-Distance to object (or distance focused at to object)”
However, the three factors photographers consider are
-F stop
-Angle of view
-Distance to object (or distance focused at to object)
Thus for all practical purposes, shooting FX results in less DOF than DX.
Toby on Apr 06 at 03:22 PM
You guys just helped me figure out a lot of things with your comments and the original post. The 12mm vs. 18mm bit is key. I ran some calculations on this amazing DoF calculator:
http://www.cambridgeincolour.com/tutorials/DOF-calculator.htm
I ran the numbers with a D300 (FLM of 1.5) vs. a D700 (FLM of 1). If I set print dimensions to 20” viewing to default, vision to default, F-stop to F/8, and focus to 2M: I then changed the following:
To simulate a D300:
Actual lens focal length: 18mm
CF: 1.5
Resulting total DoF is 3.032m
Then I simulate a D700:
Actual lens focal length: 18mm
CF set to 35mm
Resulting total DoF is 9.282m
If I swap the D300 numbers to 12mm to match an 18mm equivalent I get a total DoF of Infinite.
I’ll still probably go to the D700, just means getting that 14-24mm lens becomes pretty key.
Sean on May 02 at 11:55 PM
Nice article, both format has its own pros and cons.
However, you’re computation from 5 minutes with F8 to 10 minutes with F16 aperture is slightly off. F8 to F16 is actually two stops.
It should have been:
5min at F8 = 10min at F11
one stop in shutter speed then one stop in aperture to cancel out any change in exposure.
Carl on May 04 at 08:29 PM
You are right, Carl - I’ve changed the post to reflect that change. I sometimes screw up the f/stops, assuming f/8 is twice f/16… pesky apertures.
Toby on May 07 at 04:37 PM
Interesting post - thanks for this. I have read that the DX lenses can also be used on the full frame bodies. But my question is, if the total megapixels are the same of full frame (say 12 MP), does that mean that the resolution of the DX-size image on the full-frame will actually be much less (say equivalent to a 5-6 MP) and make for a noisier/grainier image, especially when cropping?
LA-Dub on Aug 01 at 01:44 PM
Exactly, LA-Dub. Attaching a DX lens to an FX Nikon body will trigger a cropped “DX Mode” which comes out to about 6mp or so. It results in a noisier image than shooting full frame on the same camera, but not necessarily noisier than a DX camera.
Toby on Sep 16 at 10:53 PM
Superb site Toby and an interesting article.
To follow up some of the earlier points on angle of view, perspective etc, this page is interesting (and I love the avenue of trees):
http://www.petercox.ie/perspective.php
Celidh on Sep 17 at 02:53 PM
The DOF concern may be misguided. You can stop down the full-frame sensor more to achieve the same DOF and boost the ISO to get the same exposure. Theoretically, the full-frame sensor should come out ahead in this (after changing both variables, the noise should be less). I don’t know if reality matches the theory, but it probably does.
John on Oct 02 at 11:55 PM
Nice post, thanks for the information. Just wondering if you will consider the new D7000 as it is still DX, gives us more pixels and wider ISO range with low noise rather than waiting for the D700x which still isn’t here.
Jim on Oct 17 at 10:03 AM
John: I could certainly be convinced if I saw prints to compare real-world results. I will certainly try the experiment once I do move to full frame.
Jim: from what I’ve seen, the D7000 offers some evolutionary improvements over the D300: a little extra resolution and less noise. The differences aren’t enough (for me) to warrant the purchase. I’m still happy with the prints from the D300, and will upgrade when I can get a significant boost in resolution. For me, that’s likely to be around the 20+ megapixel zone.
That’s one of the cool things about the current state of the photo industry… the gear we have is already so good that the itch to upgrade is much less urgent than it was in, say, the early 2000’s.
Toby on Oct 18 at 12:00 PM