Putting Values against Performance of Various Lenses - Aberrations

[bvf]

Lenses used in this test:

• Canon 28/2.8 IS USM
  
• Canon 50/1.8 EF STM
  
• Canon 200/2.8L EF
  
• EL-Nikkor 80/5.6 (metal version, enlarger)
  
• EL-Nikkor 105/5.6 (metal version, enlarger)
  
• Enna München 28/3.5 Lithagon
  
• Leitz Wetzlar 50/4.5 Focotar-2 (enlarger)
  
• Prinz Galaxy 135/3.5
  
• Samyang 14/2.8 ED AS IF UMC
  
• Sigma 24-105/4.0 DG OS HSM Art
  
• Sigma 105/2.8 Macro EX DG OS HSM
  
• Soligor 35/3.5 (enlarger)
  
• Steinheil München 50/2.8 Cassar S
  
• Tamron 500/8.0 SP Macro Adaptall-2
  

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This post accompanies the separate one on lens resolution, and concentrates on aberrations.

See: Putting Values against Performance of Various Lenses - Resolving Power

 

The table of results is at the end. First, some caveats, comments, and conclusions.

 

Caveats and Comments.

 

1. These results are all visual assessments rather than metrics, so there is opportunity for interpretation errors, and another observer might have come up with different scoring.

 

2. Some of the scored effects were actually very slight – such as pincushion/barrel distortion. (I was confused for a time because I could see pincushion distortion in the borders of the images whilst the lines were perfectly parallel to the edge of the monitor – turns out the astigmatism was in my spectacles!)

 

3. The test images had the saturation increased to make colour fringing more obvious when looking for CA (chromatic aberration).

 

4. I was expecting that it would be difficult to see the CA in the UV (Baader U) and IR (R72) images because of the lack of colour you normally get – especially in IR. But a couple of lenses did show severe colour fringing. For example, here are crops from the UV and IR images from the Prinz Galaxy 135mm at f/8 which show this effect, followed by the equivalent crop from Focotar which does not show the effect. (Remember that the images are about the same size on the sensor because the camera was moved for different focal lengths to get the same scaling.)

 

Prinz Galaxy 135mm at f/8, IR:

 

Prinz Galaxy 135mm at f/8, UV:

 

Focotar-2 50mm at f/8, UV:

 

5. The “Overall IQ” and “Drop of IQ at corner” were based on the resolution data in the previous post. Scores are from 2 ticks (very good) to 2 crosses (very poor).

 

6. The “Curvature of Field” was also assess from the resolution data by looking at how big an improvement in corner resolution was achieved by re-focusing.

 

7. Scores for the “Curvature of Field” to “Astigmatism” columns are from blank (=OK) to 2 crosses (very poor).

 

8. All assessments made for lenses at f/8, with the image focussed at its centre.

 

General observations

 

1. In the visible range, modern camera lenses have better aberration control than vintage camera lenses – no surprise there. However the vintage enlarger lenses are up there with the modern camera lenses.

 

2. Once you get away from the visible region, the modern camera lenses (at least at shorter wavelengths) show more aberrations and so lose their advantages over vintage camera lenses.

 

Comments on Specific Lenses

 

1. The Igororiginals come out fairly poorly across all wavebands.

 

2. The Cassar S and Lithagon both score very badly in visible, but do somewhat better in UV and IR.

 

3. The Focotar-2 and El Nikkor 105mm are stars across all wavebands.

 

4. The El Nikkor 80 also does pretty well.

 

The Table

 

Scale: √√=very good, √=good, blank=OK, x=noticeable, xx=bad.

 

[ulf]

Nice, Bernhard!

 

Are all tests done with an APC-C camera. I saw your other post after asking this.

Some of the lenses are not very well defined.

The Prinz Galaxy 135/3.5 was made in very many versions.

I also think, that canon had a 200mm 2.8 L is available in at least two different versions.

Is that canon lens really OK for UV?

[bvf]

Ulf:

 

The Prinz Galaxy 135 s the one shown in this post: https://www.ultravioletphotography.com/content/index.php/topic/4358-prinz-galaxy-135mm-f35-in-uv-not-too-bad/

 

The Canon 200mm is the original EF L version, with the built-in lenshood and no image stabilisation. I wasn't suggsting that all the lenses I tested were good for UV. I just tested all the lenses I had, including in the visible range for general photography purposes. Although they can make images through a Baader, I would not recommend any of the Canon lenses for UV - I just included the Canons in the UV test for the sake of interest, but perhaps I should just have marked them as not performing well in UV.

 

Yes,, I should have been clearer - the aberrations in the visible range were judged using full-frame images (except for the Soligor 35mm enlarging lens). The UV and IR aberrations were judged using APS-C images. I think this is OK, because I was scoring by comparing lenses within each waveband, rather than comparing visible vs. UV for the same lens.

[dabateman]

Bernard,.currently you have a single check and double check for the Canon 200mm f2.8, which implies its the same as Nikkor 80mm and better than the igoriginal 35mm lenses.

[Andrea B.]

Bernard, thank you for this excellent visual assessment.

 

I'm trying to decide where to put it for future reference.

[bvf]

Bernard,.currently you have a single check and double check for the Canon 200mm f2.8, which implies its the same as Nikkor 80mm and better than the igoriginal 35mm lenses.

 

Yes,that's true. The image quality of the Canon 200mm through the Baader U was good. But I suspect that its UV reach is very poor. The Canon 200 (and indeed the other Canon lenses) needed a lot more exposure through the Baader U than the El Niks and the IgorOriginals and all the other UV-friendly lenses. My 345BP25 filter is too small to use with the Canon 200, but I doubt it would have recorded anything - as I found with the 28mm and 50mm. So my feeling is that you can't go below 380-ish with any of the Canons, and that's why I wouldn't recommend them for UV.

 

BTW - I screwed up the Colour Cast column on this table. I'm just about to replace it. The UV colour cast for all of the Canon lenses should be Blue when WBed as for the Focotar-2: I think this points to the Canons passing predominantly the very longest UVA wavelengths.