Do all 35mm lenses have the same types of distortion?

[thebarnman]

Advertisement (gone after registration)

I'm asking about the stretching characteristic one gets with wider angle when shooting with a 35mm lens.  Does anyone know if the Leica 35mm lens have more, less or none of that stretching effect when shooting close to a subject when compared to other 35mm from different manufacturers?  

[Advertisement]

The Leica Q3 is available for pre-order at B&H Photo Video and Adorama

[Mute-on]

Sounds like you are describing perspective distortion, which is independent of optical distortion. Perspective distortion decreases as focal length increases, to a point. For example, at 50mm there is relatively little perspective distortion, and a negligible amount by, say, 75mm. On the other hand, at 35mm and wider, perspective distortion increases exponentially as focal length decreases.

Most 35mm Leica lenses have insignificant optical distortion characteristics. Other will know which have the least, but the differences will be subtle. 

[Al Brown]

The edge stretching is conditioned with focal length, not brand. What Leica lenses do have more from the leading market manufacturers like Canon, Nikon and Sony is field curvature due to their small size.
To avoid edge stretching in 35mm equivalent FOV use medium format cameras - a 45mm lens on Fuji GFX or Hasselblad that gives the same field of view as Leica 35mm will do.

Edited June 3, 2024 by Al Brown

[RMF]

47 minutes ago, Al Brown said:

The edge stretching is conditioned with focal length, not brand. What Leica lenses do have more from the leading market manufacturers like Canon, Nikon and Sony is field curvature due to their small size.
To avoid edge stretching in 35mm equivalent FOV use medium format cameras - a 45mm lens on Fuji GFX or Hasselblad that gives the same field of view as Leica 35mm will do.

Thanks for the info @Al Brown. This is really interesting as I never thought of the advantage that a medium format lens has in perspective distortion over its equivalent 35mm FOV. 

[Babylonia]

Well,

vor 6 Stunden schrieb RMF:

Thanks for the info @Al Brown. This is really interesting as I never thought of the advantage that a medium format lens has in perspective distortion over its equivalent 35mm FOV. 

Well, that is not truth at all.
Every camera - Micro Forth Thirds - APS-C - "full frame" sensor (35mm film / 24x36 mm) - medium format sensor - 6x6 cm film - 4x5 and 8x10 inch sheet film.
All photographic imaging is related to the same optical physics.

All "same" Field of view of lenses, and images made by camera's of different brand and size of sensor / film format.
(Not included specially designed lenses like fisheye lenses).
Shall have the same image "perspective" stretching when viewed prints / (or TV screen) by same "looking distance".

BUT.....
What most people don't realize is that the "perspective" stretching is dependant by this "looking distance" of the image
in relation to size of the printed image or TV screen.

A picture made by a wide angle lens.  Just print (or show) the image in such big dimensions, and look relative "closely" to the image.
Exactly in front "of the centre" / middle of the shown print.
And you shall remark, that the image is just "normal,  without stretching at the edges.

That is because you are looking "at an angle" to the sides / corners of the print.
By that the "stretched" image, shows itself with an abbreviation.

Comparable effect, when driving a car and on a road the maximum traffic speed is painted on the surface of the road itself.
The real painted traffic sign looking from above, is in a very long stretched size.
But if you look at the driver's seat in a car from a different perspective, you will see that this sign is more or less 'normal'.

To have full advantage in looking experience of photographic images, you have to take in account, the size of printed / shown images,
in relation to circumstances under which those photos are shown.
E.g. printed in a glossy magazine, or shown "big" in a gallery, or projected onto many meters wide cinema screen.

All these "physics" and perceptual experience is related to each other.
-

Edited June 3, 2024 by Babylonia

[BernardC]

That's a great summary. It reminds me of a similar explanation in Rudolf Kingslake's "History of the Photographic Lens." Among other things, this phenomenon explains why a standard lens for a Super-8 camera has a relatively longer focal length than a standard lens for a 35mm motion picture camera: Super 8 will be seen on a small screen at home, but motion pictures (in Kingslake's day) were meant to be seen on the "big screen."

With that in mind, you can minimize wide-angle distortion by keeping your camera level. That's not necessarily a cure for edge stretching, but it will hide other wide-angle "tells."

You may also find that you prefer classic symmetrical wide angle lenses to retrofocus wide angles. That's because retrofocus lenses use optical tricks to minimize vignetting and increase corner sharpness, which may affect the geometry of your images. The extreme example of this are fisheye lenses, which have very even illumination and sharpness, at the cost of image distortion. Modern wide angle lenses fight that distortion, but they aren't as true and straight as older Angulons, Biogons, or any M wide angle that is called "pre-ASPH" by collectors.

 

[thebarnman]

Advertisement (gone after registration)

On 6/2/2024 at 9:36 PM, Al Brown said:

The edge stretching is conditioned with focal length, not brand. What Leica lenses do have more from the leading market manufacturers like Canon, Nikon and Sony is field curvature due to their small size.
 

I had to read a little bit about field curvature to understand what you are talking about.  So your saying because Leica lenses are smaller than usual, a 35mm Leica lens tends to have more field curvature assumingly distortion when compared to other brand lenses. 

In particular I'll be getting into the SL3 system (this will be my first digital camera) and I'm thinking about starting out with the the APO-Summicron-SL 35 f/2 ASPH with that camera.  The only other lens I'm used to using (and have been for years) is the APO-Summicron-R 90mm/F2.0 ASPH with my R9.    

The 35 SL lens being much larger than other Leica 35 lenses, could I assume it would have less field curvature and possibly perform the same or better when it comes to field curvature when compared to other brand 35mm lenses?  

 

[Al Brown]

19 hours ago, Babylonia said:

Well, that is not truth at all.
Every camera - Micro Forth Thirds - APS-C - "full frame" sensor (35mm film / 24x36 mm) - medium format sensor - 6x6 cm film - 4x5 and 8x10 inch sheet film.
All photographic imaging is related to the same optical physics.

What you wrote is all true but by all means ALL I WROTE is true as well, only explained in simpler and different  terms.
As "all photographic imaging is related to the same optical physics" it is clear that the physics of 45mm lens gives less perspective distortion irrelevant to object distance than the 35mm lens. And the OP was talking about EDGES, not leveling.

Obviously a 80mm lens - considered a "normal" FOV for 6x6 - on a Hasselblad will not stretch corners irrelevant to angle and "size of prints" when compared to a 25mm lens - considered a "normal" FOV for M43. This is a debate about stretching edges in perspective distortion, as written in post #1. And we are most likely discussing normal and comparable observation on classic 27" monitors as this will be the biggest magnification most photographers will ever have of their photos.

Edited June 4, 2024 by Al Brown

[thebarnman]

On 6/2/2024 at 9:34 PM, Mute-on said:

Sounds like you are describing perspective distortion, which is independent of optical distortion. Perspective distortion decreases as focal length increases, to a point. For example, at 50mm there is relatively little perspective distortion, and a negligible amount by, say, 75mm. On the other hand, at 35mm and wider, perspective distortion increases exponentially as focal length decreases.

Yes, perspective distortion is what I'm referring to.  I know there has to be a stretch when using a 35mm lens when compared to lenses with longer focal lengths, but what I was wondering is...are all 35mm lenses have the same type of stretch when comparing the effect on a full sized sensor OR does Leica have a less distorted perspective look while still maintaining the 35mm field of view?    

[Al Brown]

25 minutes ago, thebarnman said:

The 35 SL lens being much larger than other Leica 35 lenses, could I assume it would have less field curvature and possibly perform the same or better when it comes to field curvature when compared to other brand 35mm lenses?  

You are correct about less visible field curvature regarding this full frame 35mm SL lens. No idea about other 35mm full frame lenses in comparison as I have not used the 35 SL. But do not forget most lenses have field curvature to some extent. I can only say that Zeiss Sony 35 full frame lens has quite pronounced field curvature.

Edited June 4, 2024 by Al Brown

[jaapv]

Perspective distortion has NOTHING to do with focal length but with the distance of the photographer to the subject. Field curvature is something quite different.