EL-Nikkor 80mm/5.6 metal vs. EDIXA-Auto-Cassaron 50mm/2.8

[Andy Perrin]

Lens test of the Nikon EL-Nikkor 80mm/5.6 metal version vs. Steinheil München EDIXA-Auto-Cassaron 50mm/2.8.

 

This was a pretty casual test -- I just slapped each lens on the camera (Sony A7S mark 1, full spectrum) and took a picture with each lens with the same settings. It's not quite apples to apples because the focal length is not the same for the two lenses, but it gives some idea of the performance you can expect, at least from MY copies of these lenses. (As we have seen, Bernard says his Edixa is much sharper, and I suspect David's is even worse than mine. But at best we have HIGHLY variable quality from the Edixa, whereas most people report good things from the EL-Nikkor. Bandpass is similar for both I think, but maybe Ulf will have to test the Edixa to compare that.)

 

Lens pics:

 

Settings:

F/8, ISO320, 1/4" for both lenses.

White balance in-camera off the street in a sunny spot using the EL-Nikkor and then not changed after that.

1.75mm S8612 + 2mm UG11 (both from Cadmium, so definitely not Chinese)

 

Bear in mind that the Sony A7S is a full frame camera (35mm) with 12 megapixels, so your own performance will vary -- if you have a 50 megapixel full frame sensor or something, you will see all the problems shown here but even WORSE.

 

The camera was balanced on the windowsill for the test, and I used the 10 sec countdown setting to avoid shaking the camera.

 

First, the whole images, resized to 1100px width.

 

EL-Nikkor 80mm ( Ignore the tree blur, it's inevitable at 1/4 second exposure):

 

 

 

Edixa-Auto-Cassaron:

 

Now a crop and resize to 200% from the center of the frame. EL-Nikkor 80mm (left) vs. Edixa-Auto-Cassaron (right):

 

Bad chromatic aberrations on the Edixa! And that's in the center at F/8.

 

Now the corner (I used the same exact pixel locations for the crop in both images.) These are 1:1 crops.

EL-Nikkor 80mm (left) vs. Edixa-Auto-Cassaron (right):

 

I trust that everyone can understand now why I am so negative about my Edixa-Auto-Cassaron!

[Andrea B.]

Andy (or anyone), is it possible that an old lens like the Edixa-Auto-Cassaron can be "adjusted" and brought into slightly better sharpness?

[Andy Perrin]

Andrea, I have no idea if it's possible to "tune" a lens, but even if you got the center sharper, the corners would still be terrible, and you wouldn't get rid of the chromatic aberration. Those are the fault of the lens design (or lack thereof, in UV).

[dabateman]

I think I broke the aperture on mine and have taken it apart a couple of times. Even reglued the plastic that holds it together. Very cheaply made lens.

It might be possible to adjust it. Maybe I should take mine apart again and see if its easyish.

[bvf]

 

Bernard says his Edixa is much sharper

 

 

Actually no - I was praising (within limits) the Steinheil Cassar S, not the Steinheil-made Edixa Auto Cassaron. These might be quite different lenses - although they perform similarly in terms of UV reach according to the UV Transmision spreadsheet.

 

So I'm not making any comment on the Edixa Cassaron as I don't have one.

 

The comment I made about Edixa was that some Edixa SLRs happened to have Cassar S lenses on them, and if you can find one it's cheaper to buy an Edixa + Cassar S (and then use the Edixa as a door-stop) than to buy a Cassar S lens on its own.The fact that both Cassaron and Cassar S (both of them 50mm f/2.8) are available on the Edixa range might indicate that the Cassar S is a premium option delivering better image quality.

[Andy Perrin]

Ok, crossed out that comment above in the original post.

[Andrea B.]

...even if you got the center sharper, the corners would still be terrible, and you wouldn't get rid of the chromatic aberration. Those are the fault of the lens design (or lack thereof, in UV).

 

Yep, can't overcome the design. But I was thinking along the lines of loose internal screws or a loose element or something like that. Or the focusing helicoid gets slippy and focus is easy to disturb. Mostly focusing helicoids get stiff and need a re-lube, but I've got a Novoflex which seems to defocus if you just breath on it. That lens could go to KEH for a clean-up & adjustment and probably come back a little bit better than when it left. I used to routinely send off any lens bought on Ebay for a routine check, clean, adjustment, but I have gotten lazy in recent years.

[Andy Perrin]

Yeah, I don't think anything can really help this lens, and certainly isn't worth putting any money into it. Whether such a thing would help for other more worthy lenses, I don't know.

[rfcurry]

I explored a lot of the Cooke-type triplets. Here is a list of some of them:

triotar, isconar, iscotar, trioplan, trinar, helomar, telomar, radionar, cassar(it), apotar, reomar, geronar, domiplan, meritar, piconar, picon, victar, elmar.

 

Most of them were UV-capable, but, IIRC, none were especially sharp. Add one more element, in the Tessar design, and you still have three groups. So, no more air/glass transitions than the triplet, with similar UV transmission (assuming similar use of crown and flint glass), but often better sharpness. Very subjective, of course.

http://uvroptics.com/images/CookeTriplet.jpghttp://uvroptics.com/images/Tessar.jpg

I found a Steinheil Munchen Cassar S 50/2.8, M42 mount, and a Steinheil Munchen Cassarit 50/2.8, L39 mount, in the workroom. I'll try to get some UV shots with them tomorrow. DV

regards,

Reed

[Stefano]

That construction looks simple to replicate. Two plano-convexes and one bi-concave. If one wants to build a DIY quartz/fused silica lens, it may be done that way.

[bvf]

That construction looks simple to replicate. Two plano-convexes and one bi-concave. If one wants to build a DIY quartz/fused silica lens, it may be done that way.

 

The problem is that you need to balance glasses with different refractive indices, colour dispersion, and curvature radius to get an effective lens. Putting 3 or 4 off-the-shelf fused silica elements together isn't going to work very well.

[Stefano]

Yes, you can't make a DIY UV-Nikkor or stuff like that, but you may be able to put together a decently sharp lens that at least has acceptable edges when stopped down. The image quality will never be even remotely comparable to an actual dedicated lens, but looking at the experiments some members did with single elements (including you, I forgot you last time), maybe you can improve the quality a bit. Chromatic aberration would be a big problem though, as that is usually corrected using different glass types, like the achromatic doublet Andy mentioned some time ago.

[dabateman]

When I go back to this test which was the whole reason why I bought the EDIX in the first place, I am still shocked how sharp the Kolari one is:

https://kolarivision.com/uv-photography-lens-compatibility/

 

They must have bought the sharpest copy in the world. The outstanding outside portrait I have never seen with my copy.

[bvf]

I am still shocked how sharp the Kolari one is:

https://kolarivision...-compatibility/

 

They must have bought the sharpest copy in the world. The outstanding outside portrait I have never seen with my copy.

 

You're right - although the Steinheil Edixa was stopped down compared to the others. And we don't know how the lenses compare at the corners or when stopped down to f/8 (the usual lens sweet-spot). But its UV transmission is the best.

 

Looks like if you've already got the Steinheil Edixa (or possibly a Steinheil Cassar S) there's no advantage in getting the Yongnuo - unless you really need the extra stop. If you haven't got either yet, looks like you can get the Yongnuo cheaper than the Steinheil Edixa (and definitely a lot cheaper than the Cassar S) - so it would be good to know just how good the Yongnuo is in UV transmission.