I’m going to make a claim that will have at least a few people wanting immediately tell me I’m wrong. They’ll cut and paste some physics stuff they found on the internet to prove it. They’ll quote thisor that popular knuclehead to prove the consensus of the illuminate are against my observations. A few will do just about anything to convince me — actually themseleves — that all it takes for a smaller format capture medium to look exactly like a larger capture medium is that oft quoted rule of thumb that ”the look” is one stop different between full-frame and APS-C (half frame).
In some circumstances that might be about right. In other situations it might not matter at all. That rule of thumb just doesn’t seem to hold up in my observations. At least not where it matters to me.
Let’s shelve the part where it does matter to me for a moment and get where it does prove about right out of the way. First up is where you might have or want lots of DOF. The extreme case of crazy wide views at relatively small apertures with your focus distance and most of the frame at long-ish distances. Yep it certainly isn’t really noticeable, everything looks about the same. The other case where it’s hard to tell is the opposite end of the spectrum where there is extremely shallow DOF where backgrounds are almost completely blended up into oblivion. Long lenses, close focus distances, wide-open huge apertures. You get the idea. In both of these extremes capture medium sizes with similar field of views and subject distances feel about the same.
How about where I happen to live my photographic life? Moderate fields of view at large to moderate aperture’s between 2 to 5 feet away. I happen to see what amounts to a huge disconnect with that one stop rule. Why is this? I have no definitive answer. I’m positive there are a lot of factors at play beyond the perfect world apples to apples math. Maybe the math is at work too. Who cares. Maybe I’m picky about it. Maybe it doesn’t really matter all that much (it really doesn’t) but I can if it bothers you or there’s just some je nes sais quoi factor you’re not getting. In any case I’ve attached a few images with similar subject to background distances. Some images from the Ricoh GR and some from the Nikon Df w/ 28mm. Do they look similar to you in terms of DOF rendering characteristics? I tried to pick them so that they did look similar without looking at any of the shooting metrics as to be as unbiased as I could.
Wait for it, here’s the punchline… All of the GR images were shot wide-open at f/2.8. I knew this going in. The blind part of this clinical study was the Df images. Guess what aperture they all turned out to be. If you guessed f/4 you are way off. They are all f/8. If anything they look like they have less DOF even at 3 stops difference.
Okay, enough images to clog up the internet for now. Which is which? All of the images of Keira (dark hair/black dress w/ white trim) are the GR. The others are the Df. They’re all pretty big if you want to open them in a new window and evaluate them with a closer view. You decide.
Ps. Sorry for this next bit of stuff but hey… I could win a free camera.