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25mm c-mount vignetting shootout

apicius9

New member
Hi,

I had wanted to do that for a long time, but never seem to find the time these days, so here is just a fast and dirty version of a comparison of several fast 25mm c-mount lenses. Here are the contenders, all 25mm,

top row:
Angenieux M1 0.95
Angenieux Bell & Howell 0.95
Zeika 0.95
Angenieux 1.4
Canon TV-16 1.4

bottom row:
Kern Switar RX 1.4
Wollensak Velostigmat 1.5
Cooke Kinic 1.5
Kodak Ektar 1.4
Pentax 1.4



I was mostly looking for the vignetting, so the motive isn't really exciting. The picture in the background gives you a slight idea how the lens handles OOF parts, the focus is on Elvis' eyes, all at ISO 200. I wanted to do it inside to challenge the lenses a bit, daylight from a window on the left. I selected 3 shots for each camera, one at 4:3 fully open, one at 16:9 fully open, and one at 16:9 at f5.6. Pictures are pretty much jpgs straight from the camera, no cropping, just a minimal bit of sharpening after resizing them.

A few general remarks:

- some lenses are more difficult to focus than others. The focus ring of the Angenieux is very close to the adapter and they are difficult to focus with my big fingers.
- the Wollensak should probably have been cleaned better before the shoot...
- The Wollensak and the Zeika were the most difficult to get sharp, may have to do with the camera sitting at the edge of the minimal distance for those lenses, but that is only speculation.
- From a handling perspective, I like the Canon and the Kodak the best. Not too small, easy to reach aperture and focus rings.

So, here are the shots in the sequence listed above, I am only showing the 16:9 format for now. If you see vignetting there, it will be worse at 4:3...

Starting with the fully open shots, then at f5.6 for each lens:

Angenieux M1






Angenieux B&H






Zeika






Angenieux 1.4





tbc.
 
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apicius9

New member
continued, first pic fully open, second pic at f5.6


Canon






Switar RX






Wollensak






Cooke Kinic






tbc.
 
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apicius9

New member
Kodak






Pentax






My personal conclusions:

- The ultra fast ones are mostly very soft fully open, so I am wondering if they are worth the price tags.
- I am surprised by how well the 'cheap' little Pentax holds up. I was going to sell it, now I am wondering...
- The Cooke paints a very interesting picture but isn't very good at capturing what my eyes see...
- The Switar RX shows some strange distortion at f5.6 - I have to double check that to make sure I didn't make an error, but maybe it has to do with the RX format?
- The Canon remains one of my favorites after this comparison.

One important limitation: Especially the older lenses would probably benefit from a very thorough inside-out cleaning. I didn't see any obvious haze but most of them are a bit weak in the contrasts. I don't know enough to say that's because of their construction or some kind of slight dirt on them...

I have a few more, but these seemed to be the most interesting ones. Please let me know what you think. If you want any other specific comparisons, please let me know - but be prepared that it may take a while before I get to it.

Aloha,

Stefan
 
V

Vivek

Guest
One important limitation: Especially the older lenses would probably benefit from a very thorough inside-out cleaning. I didn't see any obvious haze but most of them are a bit weak in the contrasts. I don't know enough to say that's because of their construction or some kind of slight dirt on them...
Yes. Cleaning is good not only for the contrast but for the speed! If you have a less than crystal clear 0.95 lens, the speed will not be that but more in the range of ~f/1.2!


On the question of "if they are worth it"? only you can decide!

Here is a shot through the Senko 25/0.95 (not as fast as the Navitar 25/0.95 though both samples are brand new!). As shot- with no crops in camera or outside the camera.




100% crop.




It is not only the focus that is important but also the exposure- in particular when one is using super fast lenses. For hand-held shots, I would recommend atleast 1/250s shutter speed (assuming there is little subject motion).
 
V

valtof

Guest
It's indeed a wonderful job, and very helpful... Congratulations Stefan !

Here are my conclusions from what I see (and from what I know by myself...).

With the subject you choose we can judge sensor covering (image circle) which was your purpose, but also distortion, which is generally the other main weak point of c-mount lenses when mounted on a G1.
What is more difficult to appreciate is indeed the ease of use but especially the character of the lens. I'm still convinced that an Angénieux f:0.95 has a much more attractive bokeh than the little Canon TV16 even if this one compete very well, and not at the same price of course.

Anyway, if I only consider sensor covering and distortion, here is the classification I would suggest :

First prize ex-aequo : Cooke Kinic and Angénieux f:1.4
Second prize : Pentax
Third prize : Wollensak (even with its quite pronounced pincushion distortion)
Fourth prize : Canon

The two Angénieux f:0.95 and the Zeika are equally OK but not covering the sensor, as for the Kodak but with much more barrel distortion.

The Kern Switar is definitely out.

For my personal concern, I would love to see a side-by-side comparison between a lens I already own, Canon TV16, ans a lens I'm looking for, Angénieux f:1.4.
But in other circumstances like : a bigger main subject (a bike for example) focused not to closely (2 or 3 meters) framed in such a way we get an important OOF background field (a bit low-angle shot with horizon ideally) - wide open or/and f:2 and uncropped, of course.

Anyway thanks again, Santa Klaus, for this very interesting benchmark.
Cheers
Christophe
 

slosync

Member
Thank you Stefan....

Very nicely done. I was especially interested in an overall test of this sort (e.g. same subject, same light, same settings).

I have the Pentax now and a Kern Switar on it's way..... I'm wondering about the Switar results you posted. Will be anxious to hear back if you get a chance to double check if something went wrong with your test.

I have a Cosmicar 25mm f/1.4 that needs some modification to get it to mount correctly in the Hawk adapter. I don't know if it's related in anyway to any of the lenses you tested, but I'm hoping it works as well as the pentax.

Here's a portrait shot using the Pentax 25mm at 1.4 of my granddaughter. I may have been just a little to close to get critical focus. I may have posted this before, please forgive the redundancy.


Regards, and thanks again
Don
 

apicius9

New member
Thanks for your comments, everyone. I agree, there is much more to it than sensor coverage, and I plan on taking more pics before I decide what to sell and what to keep - I'm really more a user than a collector...

The two that I personally want to find out more about are the Wollensak because I think it is really promising (I only got it very recently and haven't had a chance to try it out much) and the Zeika 0.95. That has the best coverage of the 0.95 ones I have but I seem to have trouble focusing it wide open, and I am not yet sure whether that is because of a long minimal focus distance, the lens being very soft wide open or some problem with the lens, I just have to play more with it.

The one that keeps fascinating me is the ancient Cooke lens which has very interesting effects when shot wide open, they mostly disappear stopped down. Here is an example:



I have to admit that I really only got interested in photography again with the appearance of the G1, so I do lack a lot of experience and skills here. For example, I am not sure I am the best person to take apart and thoroughly clean my lenses on the inside - would anybody know of a service where I can send my lenses for that? I haven't found anybody locally either (Honolulu)...

Thanks,

Stefan
 

Photomorgana

New member
Hi,
thank you for your comparison test.
I do own most of Angenieux and Switars and some Cookes and based on my files Im reviewing, the images I have are sharper wide open than yours. :bugeyes:
Switar lens is probably defective. Just my thought... (I havent encountered a bad Angenieux or Switar lens so far, and I have used and still use almost all of them including C-mount, exakta, Arri. I used many Cookes and love them too, but I never used the Kinic that you have. (I believe Kinic is not top of the line for them, Ivotal or panchro would be much better)

But as a rule of thumb none of 25mm lenses you trying will be as good as Lux-D 25mm for example. Those are creative lenses and not for pixel picking... You know what I mean...
If vignetting or distortions are more important than color reproduction, bokeh and lens signature than you have to move on to 75-100mm FOV.
 

apicius9

New member
You know, I was wondering about the sharpness because I had expected that to be a bit better than what I saw. Next weekend I will try to look at that again and make sure I don't have any systematic error in there somewhere. Maybe - don't laugh! ;) - I need stronger prescription glasses, I have seriously been wondering about that but tried to ignore it as unwelcome signs of aging :rolleyes:

As for the effects, I fully agree, these are not the lenses of which I expect ultimate sharpness or complete sensor coverage at all cost. The vignetting question just kept popping up, that's why I got curious and wanted to have a look into that. For myself, I would like to narrow it down to a total of 4 25mm lenses out of the 20 or so that I currently have - one for low light, one with full coverage, one with a nice and/or unique character and one that is very easy and fast to handle. That should fill the gap between the 35mm Schneider Xenon that I have and the 20/17 Panasonic that may show up at some point in the future.

That Switar also puzzles me, I'll check that out again - also one of the more recent ones that I hadn't even taken out to the real world, yet. Should the IQ be different between AR and RX versions?

Stefan
 
Hi,



May I add the 26mm/1.1 Macro Switar at infinity, f/5.6. The blades of the diaphragm are currently blocked, it has to go for repair, so I cannot contribute one fully open. I have posted this before, but I thought it is useful to post again in this thread, please forgive the redundancy.

Cheers
Peter
 

Leica 77

New member
Here's a portrait shot using the Pentax 25mm at 1.4 of my granddaughter. I may have been just a little to close to get critical focus. I may have posted this before, please forgive the redundancy.




Regards, and thanks again
Don
This is a beautiful portrait! :)
 


Sunflowers
Macro Switar 26mm/1.1 - ISO=100 - 1/320 @ f/5.6 - Raw Therapee



Grapes
Macro Switar 26mm/1.1 - ISO=100 - 1/4000 @ f/5.6 - Raw Therapee



Grapes - Crop from previous shot
Macro Switar 26mm/1.1 - ISO=100 - 1/4000 @ f/5.6 - Raw Therapee

 

madmaxmedia

New member
That close-up on the Switar looks great. You didn't happen to take the same shot wide open, did you? Just curious how it would look then.

You can see through the grapes. With good lighting that's a good macro subject...
 
That close-up on the Switar looks great. You didn't happen to take the same shot wide open, did you?
Thank you. Wide open, the lens is much softer, not suitable for macro. The great thing about this lens is that you can use it for soft portraits wide open and it gets very sharp at f/4 and more.
 

hakkalo

Well-known member
Hi,
thank you for your comparison test.
I used many Cookes and love them too, but I never used the Kinic that you have. (I believe Kinic is not top of the line for them, Ivotal or panchro would be much better)

.
Cooke Speed Panchro 1" F2 ELC C-Mount (Sharp & full coverage :clap:)

 

RichA

New member
Is "fast" really worth it?

Kodak

My personal conclusions:

- The ultra fast ones are mostly very soft fully open, so I am wondering if they are worth the price tags.
- I am surprised by how well the 'cheap' little Pentax holds up. I was going to sell it, now I am wondering...

Stefan
People who buy fast for things like night shots should do an experiment. Shoot with the lens wide open at a set ISO. Then, close the lens down two stops and shoot at an ISO two stops higher. Run the second shot through noise reduction software and then decide which shot is better. Sometimes, the wide open shots are so soft, lacking in contrast that the higher ISO shot turns out better. Therefore, the faster lens speed is not worth using in such a case.
 
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