Performance of Various Lenses in Macrophotography - Resolving Power

[bvf]

Lenses used in this test:

• EL-Nikkor 50/2.8 N (plastic version, enlarger)
  
• EL-Nikkor 80/5.6 (metal version, enlarger)
  
• EL-Nikkor 105/5.6 (metal version, enlarger)
  
• Leitz Wetzlar 50/4.5 Focotar-2 (enlarger)
  
• Sigma 24-105/4.0 DG OS HSM Art
  
• Steinheil München 50/2.8 Cassar S
  

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The information below is generated using a 35mm transparency as the target. This is one of a set of 3 made by Leitz back in the day to check slide projector set-up and performance, and includes some bar patterns providing a lines/mm scale. These slides are being passed on to Ulf, so they may reappear on UVP in the future.

 

I used this transparency as a target for 1:1 macro shots in a bellows-based slide copier. Tests were made for the lenses I use for UV macro. Also included are two lenses that I use in visible macro work but which are not very UV-friendly - an El Nikkor 50mm f/2.8 N (the newer plastic-fantastic version) and a Sigma 105mm f/2.8 Macro lens.

 

The numbers from the lines/mm bars would not tell much of a story as they are similar for all the lenses, so I am providing extracts from the images.

 

With a few exceptions, all the lenses performed very well. This includes the Cassar S 50mm f/2.8, which fared badly in the lens resolution measurements using a target at portraiture distance. This is probably because at 1:1 magnification the angle of view is about half of a landscape shot, and so you are enjoying the central resolving power of the lens and losing the poor image quality towards the edges.

 

ISO 100 and flash illumination was used throughout.

 

Visible - 1:1 Magnification

 

The visible shots were made on a full-frame Canon EOS 6D II. Aperture was f/8, the usual sweet spot for IQ.

 

This is what the target looks like:

 

 

Results for 50mm Lenses (Left-to-Right: Cassar S 50mm f/2.8, Focotar-2 50mm f/4.5, El-Nikkor 50mm f/2.8 N plastic version. Top Row is at centre of frame, Bottom Row is at the corner of frame.):

 

 

Results for longer lenses (Left-to-Right: El-Nikkor 80mm f/5.6 metal version, El-Nikkor 105mm f/5.6 metal version, Sigma Macro 105mm f/2.8. Top Row is at centre of frame, Bottom Row is at the corner of frame.):

 

 

The Cassar S performs well. There is a small amount of flare, and slight softness at the corner.

 

The El Nik 80 and 105 (both older, metal versions) also did well. The Sigma Macro lens is probably the best - as it should be, as this is what it is designed for.

 

The real surprise is how poor the El Nik 50 N was, as I have always been impressed with its image quality in macro work. But I have always used it at magnifications greater than 1:1, so I tested the 50mm lenses at a greater magnification.

 

Visible - 3.3:1 Magnification

 

This is what the full images to test centre and edge looked like:

 

 

Centre and Edge results for the 3 50mm lenses(Left-to-Right: Cassar S 50mm f/2.8, Focotar-2 50mm f/4.5, El-Nikkor 50mm f/2.8 N plastic version. Top Row is at centre of frame, Bottom Row is at the corner of frame.):

 

 

Now the El Nik 50 N is cooking with gas! The Cassar S is also good apart from a touch of flare.

 

UV - 1:1 Magnification

 

These shots used a Baader U filter. The camera was a Sony A6000 with an APS-C sensor. Aperture was f/11, as optimum aperture is smaller in UV.

 

The full image looked like this:

 

 

Here are the results. Only one image per lens (Left-to-Right: Top Row: Cassar S 50mm f/2.8, Focotar-2 50mm f/4.5, El-Nikkor 50mm f/2.8 N plastic version; Bottom Row: El-Nikkor 80mm f/5.6 metal version, El-Nikkor 105mm f/5.6 metal version):

 

 

All lenses performed very well, and it's difficult to see the differences. The Cassar S and El Nik 50N are slightly soft, but it's pretty marginal. The El Nik 50N image is dimmer, reflecting its poorer UV transmission.

 

IR - 1:1 Magnification

 

These shots used an R72 filter. The camera was a Sony A6000 with an APS-C sensor. Aperture was f/5.6, as optimum aperture is larger in IR.

 

The full image looked like this:

 

 

Here are the results. Only one image per lens(Left-to-Right: Top Row: Cassar S 50mm f/2.8, Focotar-2 50mm f/4.5, El-Nikkor 50mm f/2.8 N plastic version; Bottom Row: El-Nikkor 80mm f/5.6 metal version, El-Nikkor 105mm f/5.6 metal version):

 

 

The El Nik 50 N is softer than the others, which are all pretty similar. Overall, the IQ is poorer than in visible and UV, and there sems to be more sensor noise. Note that the El-Nik 105 element was from an image at only 2:3 magnification and so has been enlarged more the other elements.

[Andy Perrin]

The overall image reminds me a little of the pattern they used to show on TV after the station went off the air (in the US, anyhow), back when TV stations used to go off the air...

[Andrea B.]

Thank you, Bernard.

I find this quite interesting and I'm learning a lot too!!

 

I'm going to suggest captions above each photo to make things extremely clear.

I'll add them and then take your feedback if I've messed up anything.

(Or if you don't like them.)

Sometimes people access websites on small cell phone screens and the lens names

could be hard to read.

 

Also we need to identify each lens more fully by using its focal length and lens speed.

Cassar S 50/3.5 or Cassar S 50 mm f/3.5

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Example of what I meant. But it's your work and your call !!

 

Visible at 1:1 Magnification

 

The visible shots were made on a full-frame Canon EOS 6D II.

Aperture was f/8, the usual sweet spot for IQ.

 

Leitz Test Target

Here is what the 35mm transparency test target looks like.

{photo here}

 

 

Results for 50mm Lenses

L to R: Cassar-S 50/n.n, Focotar-2 50/n.n, EL-Nikkor 50/n.nN

{photo here}

 

 

Results for Longer Lenses

L to R: EL-Nikkor 80/5.6 (old metal), EL-Nikkor 105/n.n (old metal), Sigma 105/n.n Macro

{photo here}

 

Comment

The Cassar S 50/n.n performs well. There is a small amount of flare and slight softness at the corner.

 

The El Nik 80/n.n and 105/n.n (both older, metal versions) also did well. The Sigma Macro lens is probably the best - as it should be, as this is what it is designed for.

 

The real surprise is how poor the El Nik 50/n.n N was, as I have always been impressed with its image quality in macro work. But I have always used it at magnifications greater than 1:1, so I re-tested the 50mm lenses at a greater magnification.

[Andrea B.]

added

 

I would add something reminding your readers about variation in lenses due to age, wear and so forth.

Maybe your EL-Nik 50 is an anomaly??

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NOTE: humor alert!

Rules for Technical Writing

Tell 'em what you are going to tell 'em.

Tell 'em.

Tell 'em what you just told 'em.

 

:grin: :grin:

(( But, that's only partly a joke. Tech info bears repetition quite well

in Introduction, Main Work, Summary))

(((We always tossed around those Rules for Tech Writing at Bell Labs when I was there. Fun times at the old labs.)))

[bvf]

 

Maybe your EL-Nik 50 is an anomaly??

 

 

I don't think so. It's just not very good at 1:1 - no reason why it should be, as it wasn't designed for that. It provides superb results at higher magnifications.

[bvf]

 

I'm going to suggest captions above each photo to make things extremely clear.

 

 

Andrea - I've added captions as you've suggested. I haven't repeated the lens details in the subsequent text.

[Andrea B.]

Looking good.