I completely agree with you on this. It's what I've read and experimented. But I'm not going to do and post tests just to prove my point on this matter.
Fx vs Dx Comparisons
- Thread starter Rick M
- Start date
I completely agree with you on this. It's what I've read and experimented. But I'm not going to do and post tests just to prove my point on this matter.
This is one of those things than can be debated till' the cows come home...
No blanket statement can be made either way.
In general, lenses become sharper closed down 1 or 2 stops and it depends on the lens.
There are plenty of exceptions I'm sure.
You can find the "sweet spot" for a lens/body combination here:DxOMark - DxOMark by DxO Labs
No blanket statement can be made either way.
In general, lenses become sharper closed down 1 or 2 stops and it depends on the lens.
There are plenty of exceptions I'm sure.
You can find the "sweet spot" for a lens/body combination here:DxOMark - DxOMark by DxO Labs
Yes... but as good as it is you will see its still better even though not by much when stopped down to F8.
There maybe a specialest design lens out there that has a big aprature and performs best wide open but Ive
yet to see it. More to the point, it would certainly be the exception to the rule.
The Nikkor 28/2.8 AIS is good example of what you all are talking about...it displays a tiny bit of coma at 2.8, one stop down F4 the coma is gone and the lens is at it's peak, second stop down F5.6 the lens is already diffraction limited...so the sweet spot is one stop down from wide open...
The Noct Nikkor is different than the rest...it is as sharp at 1.2 as it is at 5.6 or 8 or even 11...because there absolutely zero spherical abberation in the middle at 1.2...it is completely coma free even at 1.2...it's way more contrasty than any other Nikkor ever made...the trade off is softness in the corners plus some barrel distortion...light fall off is the only thing that is improved when you stop a Noct Nikkor down...
The Noct Nikkor is different than the rest...it is as sharp at 1.2 as it is at 5.6 or 8 or even 11...because there absolutely zero spherical abberation in the middle at 1.2...it is completely coma free even at 1.2...it's way more contrasty than any other Nikkor ever made...the trade off is softness in the corners plus some barrel distortion...light fall off is the only thing that is improved when you stop a Noct Nikkor down...
Not according to this guy or anyone else. It still performs better stopped down.
Its a truly remarkable lens but its still no different to any other lens. It gets sharper on stopping down 2 or three stops.
The only lens I know of that is a exception to this is a mirror lens with a single fixed aprature lol
http://www.kenrockwell.com/nikon/50mm-f12-sharpness.htm
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Yeah this is all good and well with all this talk about sharpness and FX and DX...personally I think sharpness is over frigging rated...that is why I don't give a rat's @ss about megapixels really either.
BTW probably eight times out of ten I shoot at about a stop or two down from wide open...the other two times I shoot at f8!
BTW probably eight times out of ten I shoot at about a stop or two down from wide open...the other two times I shoot at f8!
Dr Daniels
Senior Member
My cheap opinion on the subject is that for portraits and landscape, the FX format is better than DX. Some call it a myth, but the Dof is generally better on a FX frame. Having a bigger sensor size is better for that alone. Just look at photographs taken on Medium Format digital backs at the same aperture to a 35mm frame, the dof is a lot more better on Medium format because of that large sensor.
So armed with a couple of very fast primes such as 85mm f/1.4, 135mm f/2 and the feel of your portrait images from a FX frame will have a better feel than on the DX frame. Some people disagree with that though!
So armed with a couple of very fast primes such as 85mm f/1.4, 135mm f/2 and the feel of your portrait images from a FX frame will have a better feel than on the DX frame. Some people disagree with that though!
DOF is obviously wider on DX and wider still on four thirds than FF. You are obviously talking about FF giving a more narrow DOF.
Its pretty easy to obtain good narrow DOF with APSC and not that difficult even with four thirds.
The bigger the format the more easy it is to obtain out of focus backgrounds. I wouldnt say its better in any way shape or form though in reality.
The quality of the bokeh genraly rests on the lens in use rather than any other consideration. As for landscape work, people are genrally after more doff, not less. Ive tried and used all four formats. All formats have there pros and cons.
AperturePriority
New member
What you don't get is I was talking about sharpness vs DoF of the lens Jeff. Pro photographers talking about "sweetpoint" of a lens including those factors like ligh fall off, spherical abberation, softness at the coners, distortion,... That is right. But that doesn't mean the sharpness of a lens is best at its "sweetpoint".
Take any of your lens and test and you gona see that. Even with a 50mm serier E f/1.8, pictures taken at 1.8 have sharpness at center better than those taken at its sweetpoint 5.6.
The more you gain DoF in stopping down your lens, the more you loose your lens sharpness. Nothing is free.
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AperturePriority
New member
I agree with you in the landscape pictures, FX or Medium formats are better because they get less distortion. With the same FoV in same landscape photo, your FF lens focal 48mm gives less distortion than my 32mm focal lens on a DX camera.
But for portraits, it goes all the way around. And also, since DX format only get part of FoV compare to FF; using the same lens (85mm f/1.4 for example) the DX format can avoid distortion better than FF at wide open apertures.
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