Too wide of a lens used...? [Archive] - Large Format Photography Forum

Cor

9-Aug-2021, 05:18

Hi,

Due to circumstances I shot a subject (an open bridge) with a too wide of a lens, I used my f5.6 65mm SA while the scene could have been captured with my f8 90 mm SA. So when printing I did not use the whole negative but a part of the 4*5 negative. I was wondering if I would re shoot the scene with the 90 mm lens (from the same position), and print the whole negative, would the print be the same ?

I think in theory it should, but in practice I wonder, the "distortion" and the spatial relation ship between the foreground, lamp posts, open bridge and trees in the background I feel are different between the 65 mm and 90 mm.

Apart from re-shooting and testing myself; what would you think or experienced ?

thanks,

best,

Cor

fotopfw

9-Aug-2021, 05:24

Cor

9-Aug-2021, 05:46

If you shoot from the exact same point, the perspective of a 65 and 90 are exactly the same, the 65 just covers more. When you have to crop that, quality will suffer, question is, if that's noticeable, so what's the degree of enlargement?

yes, I realize that the loss of quality when not using the complete negative, and thus enlarging more is perhaps the biggest drawback; I usually print my 4*5 negatives on 30* 40 cm paper, sometimes (rarely) 50*60 cm. I do not think this enlargement noticeably suffers. The negative in question is Maco Ir film, and I used f32 to get everything sharp, this combination is not the sharpest anyway.

Best,

Cor

Corran

9-Aug-2021, 06:43

Perspective is only controlled by the camera (film) position, not lens. Some lenses may have inherently more or less pincushion or barrel distortion (lines not being straight) but likely that is not an issue for either of your lenses - and they are even the same design.

Cor

9-Aug-2021, 06:55

Thanks !

Got quite some distortion at the edges, ie leaning in traffic lights etc. But that was to be expected, since I had to point the camera up to record the open bridge parts which were vertical now. The 65mm f 5.6 has some coverage, but I use it on a flat board on a Linhof Color (still mange even than a 1-2 cm raise). Anyway these traffic lights were excluded from the print anyway, but than I got a bit in doubt, although I knew in theory it should not matter.

best,
Cor

Corran

9-Aug-2021, 07:09

If you a bit adventurous, you could correct some of the perspective distortion caused by tilting your camera/film up in the darkroom by tilting your baseboard or easel. DOF can also be controlled via tilting the lens on your enlarger, so that the tilted paper isn't half out of focus. Depends on how tilted you were! I've done this to correct very slight errors in my horizontal perspective or when I ran out of image circle.

Cor

9-Aug-2021, 07:30

I have seen the trick in books, but I rather not mess with the alignment of my enlarger, even though it is Durst L1200 Laborator, and did not wanted the leaning distracting verticals in the final print anyway.

Best,

Cor

AA+

9-Aug-2021, 13:53

I think your best advantage would be to use the longer focal length lens and render the camera back more vertical than with your previous shorter focal length lens.

Best wishes --- Allen Anway

Drew Wiley

9-Aug-2021, 15:48

Phrased less technically, especially wide lenses do lend more of a "stretched" look from the center outwards, like a rubber band pulling the scene by its corners. This is unrelated to either barrel or pincushion distortion per se, and simply comes with the territory of certain lenses, so to speak. I find that look quite annoying, regardless of the film format involved. There is also going to be more illumination falloff from center to edge with a shorter lens of equivalent design. If necessary, that can be corrected with a center-graduated neutral density filter. I've always thought of 65 and 75mm lenses on 4X5 as last resort options when photographing cramped interiors like kitchens and bathrooms. But some people are addicted to them. I'm personally addicted to the look which longer lenses provide, and try to back away somewhat if possible. That automatically provides a large image circle without risking a stretched or warped look.

ic-racer

9-Aug-2021, 17:38

Bob Salomon

9-Aug-2021, 18:29

If you are unhappy with the resolution of your cropped image, you should re-shoot it so it fills the whole frame.
The perspective of all lenses is the same. Perspective only changes when you move the lens with respect to the subject.

No. It changes only with camera position. Moving your lens around has no effect on perspective. Moving the camera closer or further away or to one side or the other changes perspective.

Mick Fagan

9-Aug-2021, 22:09

I exposed these two sheets in September 2018 on a nice spring day. My final choice of lens was chosen due to what I wished to photograph and the framing I wished to achieve. I chose a 90mm lens and was quite happy with my choice.

On a whim I then decided to put my 65mm lens on. The position of the camera didn't change, all I did was change the focus. The 65mm had a centre ND filter which obviously changed some settings and the 65mm has a different optimal aperture, other than that, everything was identical.

I have electronically cropped the 65mm picture to the same edges as per the 90mm lens, printed it out on normal office paper, then superimposed it on top of a similar office paper print of the 90mm lens on a light box. So close to each other they looked like they were from the same negative.

Both images you see here, are effectively the full frame of the negatives.

Some food for thought.

Mick.

218537218538

Cor

10-Aug-2021, 00:03

Thanks for all the feedback, and for the clear example above, Mick !

I am now reassured, there is no need for me to re-shoot the scene with the 90 mm SA. the scene is such that I would have to use the exact same vantage point to place the camera, and the loss of resolution caused by not printing the whole negative (I guess I loose about 2-3 cm around) does not bother me, and has the added "bonus" of loosing the light fall off. I agree with Drew, the 65mm SA is my least used lens, I thought about getting a 75mm lens instead, but thanks to this discussion I won't gain to much anyway, I can always crop afterwards if needed..;-)..

Best,

Cor

maltfalc

10-Aug-2021, 07:37

No. It changes only with camera position. Moving your lens around has no effect on perspective. Moving the camera closer or further away or to one side or the other changes perspective.no, perspective is determined by the position of the lens' no-parallax point. you can move the rest of the camera around any way you want or even pivot the lens around that point and it won't change the perspective.

Bob Salomon

10-Aug-2021, 08:29

alan_b

10-Aug-2021, 10:31

no, perspective is determined by the position of the lens' no-parallax point. you can move the rest of the camera around any way you want or even pivot the lens around that point and it won't change the perspective.

No, it’s determined only by camera position.

maltfalc is correct, as is easily observable at tabletop or closer distances. Shift the lens and you'll immediately see the parallax/change in viewpoint. Move the whole camera, then counter-shift the lens to it's original position, and the projected spatial relationships of the objects in scene are back where they were. Shifting the back-only also works to maintain perspective.

At longer distances though, there's little difference between lens/camera position, so in that case you're right for all practical purposes.

ic-racer

10-Aug-2021, 17:13

If you move the camera but put the lens back to the original position (with shift, rise or fall) there is no change in perspective. Only when the lens is moved will perspective change.

alan_b

10-Aug-2021, 17:40

That’s what I said?

maltfalc

11-Aug-2021, 08:35

No, it’s determined only by camera position.

*sigh* if you move the entire camera, including the lens, that changes the perspective only because the lens has changed position. every other part of the camera is irrelevant. if you disagree, please tell me which parts of the camera besides the lens are affecting perspective and how.

Bob Salomon

11-Aug-2021, 09:14

*sigh* if you move the entire camera, including the lens, that changes the perspective only because the lens has changed position. every other part of the camera is irrelevant. if you disagree, please tell me which parts of the camera besides the lens are affecting perspective and how.
When you change camera, including lens, position you change perspective.

maltfalc

11-Aug-2021, 09:38

When you change camera, including lens, position you change perspective.but only the position of the lens matters. the position of the rest of the camera makes no difference. and "moving your lens around" without changing the position of the rest of the camera does change the perspective.

Doremus Scudder

11-Aug-2021, 10:28

Bob,

You're wrong on this one. The lens is the "eye" or "projector" of the optical system. Sure, moving the film around without moving the lens will affect the projection perspective (e.g., rendering of parallel lines, etc.) and the framing, but the relation of objects in the scene will remain the same.

Conversely, if you move the lens without moving the film, you're changing the point of view of the system and, thus, the perspective. This is most evident in close-up work when moving the lens results in a marked change in viewpoint to the scene, less so at more common photographing distances.

Of course, moving "camera position" moves the lens as well. The above is a more accurate way of thinking about it, though.

Best,

Doremus