mark fewtrell
Member
I think its safe to say we know the fx slr rule. Inverse of the focal length minimum. What are we looking at with the above lenses and backs. Is it fx equivalents? Is the shutter being in the lens relevant? I'm asking because there are suggestions that the minimum is less than say fx equivalent.
Spanik
Well-known
The 1/length guideline is independent of format. The shutter being in the lens is more or less relevant as this kind of shutter gives less vibrations. But at the same time, the big heavy mass of the camera dampens movement and vibrations a lot. OTOH I do move a lot more with the shutter release on the left hand side.
mark fewtrell
Member
Thanks Spanik.
Roger Hicks
Veteran
Sorry, but unless I am misunderstanding you, you have got this completely wrong. It is totally dependent on format, because it is totally dependent on magnification. This is how users of 4x5 inch press cameras with 135mm lenses (about 38mm equivalent on 35mm) could get away with shutter speeds of 1/10 if they slouched against a wall. They certainly didn't use 1/125 or faster most of the time.
Smaller formats require higher speeds -- an 18x27mm format will need 1/150 where 24x36 requires 1/100, for example -- whereas larger formats allow longer ones: with 56x84mm (6x9cm nominal) 1/100 on full frame 35 would translate to about 1/50 or even 1/40.
In other words, with a 105mm lens on 6x9 cm (about 45mm equivalent on 24x36) you'd need 1/45, the 35mm equivalent.
Also, it's a fairly useless guideline anyway, even with full frame. With wide-angles you can often get away with much longer shutter speeds -- 1/8 with a 15mm lens on 24x36, for example -- whereas with long lenses you often need to go faster: with a 200mm lens you certainly need 1/250 most of the time and often 1/500 will be sharper.
On top of that, there's a question of how steady you can hold the camera -- and, as you point out, the ergonomics and smoothness of the shutter release matter too. A 38mm Biogon on a hand-held Alpa gives a great deal more resolution than the same lens on a Hasselblad SWC because the Alpa is much easier to hold steady and the release is smoother.
Cheers,
R.
besk
Well-known
Well said. Since magnification of larger formats is less ---to obtain a given
printed size it stands to reason the degradation due to movement would have less effect.
Wish the same was true with depth of field for a given f stop for different formats.
printed size it stands to reason the degradation due to movement would have less effect.
Wish the same was true with depth of field for a given f stop for different formats.
retinax
Well-known
Hello all, although I've been a lurker for quite a while, this is my first post, and I'm not sure if it's a smart move to question an authority like you, Roger, in my first post... anyway I'll outline my thoughts, may it just be to find out where I'm erring:
Although I have no experience with formats larger than 35 mm, my reasoning leads me to think that the only variable the matters, mass of the camera etc. aside, should be the angle of view. Because most blur is induced by "turning" the camera a little, rather than shifting it in a linear fashion (except at short distances), the proportion of the image that gets smeared is the same, regardless of the negative size. If I'm not overlooking anything so far and the issue is proportional to image size, the enlargement shouldn't matter.
I believe the OP's line of thinking holds if you want to the best use of the resolution out of your negative, i.e. print the larger negative larger than the smaller one. Than you would need faster shutter speeds if you're using a higher resulution camera, that could also be a small format one though.
In other words, it depends on how big you want to print.
Hope my wording is comprehensible, I'm not writing in my native tongue. Please correct me where I'm wrong!
J.
Roger Hicks
Veteran
Turn it around.
We've all seen (and most of us have taken) 35mm pics that are fine at 4x6 inches/10x15 cm, but which, on greater enlargement, aren't sharp. In other words, enlarge both the subject and the blur by 3x and you won't see the blur. Enlarge both by (say) 10x and the blur may become very clear indeed. Use a larger format and you enlarge it less.
A 12x15 inch shot off 35mm is just under 12x. Off 6x9cm it's about 5x. Off 4x5 inch it's about 3x.
Cheers,
R.
Spanik
Well-known
You're right if you consider the final enlargement and circle of confusion. My tought however is that you use larger formats to print larger, not the same size with less enlergament. But the amount of smearing will only depend on the focal length.
Or am I seeing this wrong as well?
Or am I seeing this wrong as well?
Roger Hicks
Veteran
Fair enough, but I doubt most people do. I never have and I don't think many others do either. If the aim is (say) a 12x16 inch print, you can use longer exposures on the larger formats.
Cheers,
R.
oftheherd
Veteran
Everything written by Mr. Hicks is correct (of course 
). With regards to the Super 23, there is no mirror slap, the mass of the camera, lens, and back, means there should be less shaking during shutter release; the in-lens shutter does not move across the film plane so the whole film gets the light at one time, not different portions at a time; using the shutter-handle should lessen camera shake.
Best way to know, since it will also depend one your strength and steadiness, is to go out with some film and experiment. Keep good notes.
). With regards to the Super 23, there is no mirror slap, the mass of the camera, lens, and back, means there should be less shaking during shutter release; the in-lens shutter does not move across the film plane so the whole film gets the light at one time, not different portions at a time; using the shutter-handle should lessen camera shake.Best way to know, since it will also depend one your strength and steadiness, is to go out with some film and experiment. Keep good notes.