I have read how to choose f/stop at the following link,(http://www.largeformatphotography.info/fstop.html) but I have the impression you need to stop down further with LF lenses.
If I would normally use f/1.4 or f/2.0 with my D700, what would give a similar bokeh effect with my 210mm f/5.6 Sironar? Do I need to always try for f/22, f/32, f/45 etc?
Sorry, but I have not hooked up with any local LF KC user yet that can address my newbie questions.
If you're using f1.4 or f2 you're clearly not looking to get a deep depth of field. If you're looking for a sharp plane of focus with a lot of oof areas then shooting the 210 Sironar at 5.6 would do that. Or even at f8.
ETA: the 'bokeh' effect you're referring to is not just a function of f-stop, but also number of aperture blades, optics of the lens, film format, and any number of other reasons I don't know about yet.
"but I have the impression you need to stop down further with LF lenses."Originally Posted by timberline12k
Well, it is possible to stop down further to gain depth of field, due to less enlargement. Consider how many times you have to enlarge from tiny (35mm) sized digitial or film "negative" to print 16x20, vs enlarging a 4x5 or 8x10 negative to 16x20 print size. You just don't see the diffraction effects of lenses stopped down to f22-f32-f45 with 8x10 enlarging to this size, and most 4x5 users stay around f22 or less when trying to make sharp images with enough depth of focus even with swings/tilts etc
With modern LF lenses, most of us don't spend much time looking for good bokeh with the lens wide open (and you certainly won't gain it by stopping down to F22-f32-f45).
However, if you are looking for interesting out of focus effects, do a search in this forum for pictures posted by Jim Galli and others in these threads. They often make use of older lenses, including petzvel's, that were commonly used by pictorialists to achieve remarkable effects in the out of focus regions. Some of the Ross lenses and Pinkham lenses are especially desireable for these effects. All these lenses are used wide open (and often with additional softening controls on the lenses). Unfortunately most of these lenses don't have shutters (which means an additional primitive Packard shutter) or they have a primitive Studio shutter. (And some of these older lenses have Iris blades that are quite different than modern irises -- for instance a verito in my collection has some strange ends on the studio shutter that are only in play while partially wide open -- and the number of blades and the shape clearly impacts the bokeh effects )
YMMV. Bottom line - I don't think you'll be happy with the bokeh of even a wide open 210/5.6 Sironar....
Large format lenses are longer than their 35mm counterparts... A 210mm lens on a view camera will give you similiar depth of field as a 210mm lens in 35mm. Pretty shallow DOF when wide open. A 210mm lens on a 4x5 is slightly longer than normal whereas a 210mm lens on a 35mm is considered a long lens (or telephoto)
Many large format photographers are trying to get maximum depth of field so we use a combination of stopping the lens down and adjusting the plane of focus to get everything sharp. A 28mm lens for 35mm has a fair amount of natural depth of field wide open, but in order to get a similar angle of view, a 4x5 shooter has to opt for a 90mm lens which has way less DOF wide open than the 28mm.... so you stop down to compensate (and/or tilt)
I'm not sure if f5.6 on your 210mm lens will will have the same DOF as f1.4 on a 50mm lens... I would think it would be close, but I don't really shoot wide open.
Robert Oliver
I now think I understand that I am not limited to the high f/stops, i.e. f/22, f/32, f/45 etc. and that I can use f/5.6, f/8 etc. if I want. I will try to study the photos to learn how the DOF is different with a 210mm on a 4X5 vs a 60mm on a 35mm even though the perspective may be similar.
You are, however, limited by lens coverage, which varies from one lens to the next and is one reason that you may have to stop down to a smaller aperture. Not sure what your 210 Caltar coverage is wide open, but if it covers 4x5, it probably only barely covers.
The Caltar is the same as the 90mm Rodenstock Grandagon N f/4.5.
Image circle @ f/22 is 236
4X5 excess coverage is 82.3
4X5 excess coverage % is 34.87%
According to the charts on this site. I think that means I have the ability to make some tilt, rise and swing adjustments.
I don't know how to determine image circle at f/5.6
As others have mentioned, coverage is part of the factor, check for stats on your lens to be sure, but as an example,
Nikon lists the image circle of a 210mm at 243mm at f 5.6. But it increases to 295mm at f 22.
Either way you are fine with a 210 on a 4x5 but it may be an issue with a 150mm lens where the coverage is only 174mm at 5.6 and yet a comfortable 210mm at f 22.
For your 90mm, Nikon lists the coverage at 154mm wide open and 235mm at f 16 on the 4.5 version of the lens and 235mm at f 22 on the f 8 version.
I don't have stats for your brand, but I hope that is of some help.
Much better than looking at photos would be to check it mathematically with the appropriate DOF equations. You will then compare and know it exactly and for all your needs.
Or, go toMuch better than looking at photos would be to check it mathematically with the appropriate DOF equations. You will then compare and know it exactly and for all your needs.
www.dofmaster.com
and download a handy tool. You can play around.
But the depth of field of a 35mm system 50mm lens at 1.4 is much much narrower than the depth of field of a 210 on 4x5 (or the more correct "normal" field of view 150mm lens on 4x5).
Give it a try - it works well.
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