Another way of looking at this is that our sense of compression is determined by distance from the subject. Our choice of lens merely allows us to fill the frame accordingly.
The above image was shot with a 150mm lens. It doesn't feel compressed.
This image was made from the same location and has a greater sense of compression.
Was it shot with a 240mm lens or is it simply a crop of the above image ? Resolution aside, is there any way to tell ?
Angle of view is a crop
DOF is real
Bellows flare?
Well, not for your sample shot, but perhaps we can see it very well in the DOF vs OOF roll off.Originally Posted by Ken Lee
At /5.6 and 3m dist portrait the 150mm has 4x more DOF than the 300mm, 0.43m vs 0.1m.
If we stop the 300 to /22 then we have simlar 0.41m DOF.
Then we can compare the crop from the 150 at /5.6 and the entire sheet with the 300mm at f/22, both having same DOF, but... is OOF blur to roll off in the same way ? will CoC grow in the same way beyond DOF range ?
The poster's question was about compression. If he likes to experiment, he can easily simulate various focal lengths before making a lens purchase. If cropping is acceptable, he can... crop.Well, not for your sample shot, but perhaps we can see it very well in the DOF vs OOF roll off.
At /5.6 and 3m dist portrait the 150mm has 4x more DOF than the 300mm, 0.43m vs 0.1m.
If we stop the 300 to /22 then we have simlar 0.41m DOF.
Then we can compare the crop from the 150 at /5.6 and the entire sheet with the 300mm at f/22, both having same DOF, but... is OOF blur to roll off in the same way ? will CoC grow in the same way beyond DOF range ?
Yes, Ken, compression it's the same, but your question was "Resolution aside, is there any way to tell ?"
The OP sample shots show very different DOF, IMHO regarding Depth there is much more in the DOF management and shading than in the compression, at least in portraiture...
of course OP has the choice to shot the 150 at the 210 distance and later cropping to frame like if it was the 210.
Here are examples of portraits shot at various focal lengths on a full frame DSLR.
https://mcpactions.com/2010/07/21/th...rs-experiment/
As you can see, the longer the lens, the more compression there is. A 150mm lens on 4x5 would be similar to a 50mm lens on the full frame DSLR. A 300mm would be similar to a 100mm.
There is no right or wrong answer with which focal length is best but a longer lens will slim the face more and a shorter lens will round the face. Some portrait photographers try to match the focal length to the shape of the face. Everyone wants to look good!
Except a 180 is the normal lens for 57.
Good control of lighting will mold the face to flatter and reduce or eliminate unwanted shapes and details. It takes more then a lens and distance for portraiture.Here are examples of portraits shot at various focal lengths on a full frame DSLR.
https://mcpactions.com/2010/07/21/th...rs-experiment/
As you can see, the longer the lens, the more compression there is. A 150mm lens on 4x5 would be similar to a 50mm lens on the full frame DSLR. A 300mm would be similar to a 100mm.
There is no right or wrong answer with which focal length is best but a longer lens will slim the face more and a shorter lens will round the face. Some portrait photographers try to match the focal length to the shape of the face. Everyone wants to look good!
John rounded up.
Or doesn’t consider 5x7 to be a viable format worth mentioning.
Bob, I ask, would the 180mm be considered normal for portraiture and the 210mm considered normal for landscape ?
In portraiture we usually give bellows extension to the 180mm because the near subject, thus lowering the angle of view like if it was perhaps a 210 at infinite?
At the end the 57 diagonal is 208mm, so by general definition of "Normal" the 210mm nails it for 57, but a close subject projects bigger than expected on film because bellows extension, so would the 180mm be the normal ?
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