Stacking Low Cost Enlarger Lenses For High-End Image Quality

Have questions about the equipment used for macro- or micro- photography? Post those questions in this forum.

Moderators: rjlittlefield, ChrisR, Chris S., Pau

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Stacking Low Cost Enlarger Lenses For High-End Image Quality

Post by RobertOToole »

Just picked up some new-in-the-box SK Componon lenses, 4/28, 4/40 for $50 ea. (I know thats not that very cheap for Componons but at least the seller included free shipping and they are new)

Hopefully these will work well reversed in lens stacked combinations. I did try one combination and it looked surprisingly sharp!

Image


Boxes are labeled ZylinderKroerper (cylinder lens?) Componon and the serial number dates these to between 2005-2008.

Front threads are 30.5mm x 0.5mm. The front lens cell conveniently un-threads to provide easy access to the aperture disk but looks like the disks are glued in place.

Any experience with these?

Robert

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

Found this translation:

Zylinderkörper, noun: cylinder body

FYI Schneider Optics refers to these as industrial mount in the US.

I have also seen the 4/40 and 4/28 in a thicker heavy duty lens barrel.

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

After owning about a dozen Componon 28/4s and a few SK 28/2.8s, 35/2.8s and 35/4s I have never seen a wide angle componon perform like this. For reference see this test: https://www.closeuphotography.com/4x-lens-test-part-3

Turns out the performance of the componons when stacked are completely different than setup with extension only. They are not only sharper in the center but the sharpness consistent and extends from from corner to corner.

The 28 and 40mm seemed to be tuned to be consistent from edge to edge so they might be sharper at a wider aperture or with the aperture between the rear and front lens or the corner performance many suffer at a wider aperture.

Sample images:

A6300 APS-C Body+

Scheider Kreuznach Makro-Symmar 120/5.6 +
Scheider Kreuznach Componon 40mm f4 Cylinder Lens

Uncropped and resized with crop areas outlined:

Image

Upper left corner at 100%

Image

Upper right corner at 100%

Image

Additional shooting notes:


Scheider Kreuznach Componon-S 50mm f3.5 Cylinder Lens +
Scheider Kreuznach Componon 28mm f4 Cylinder Lens

Very good sharpness center to edge but soft extreme corners due to vignetting.
Heavy corner shading.
Some field curvature.


Scheider Kreuznach Makro-Symmar 120/5.6 +
Scheider Kreuznach Componon 28mm f4 Cylinder Lens

Good sharpness center to corner
Almost no corner shading.
Some field curvature.


Scheider Kreuznach Makro-Symmar 120/5.6 +
Scheider Kreuznach Componon 40mm f4 Cylinder Lens

Very good sharpness center to corner, edge to edge.
No corner shading.
Some field curvature.

Scheider Kreuznach APO-Componon Line Scan 90mm f4.5 +
Scheider Kreuznach Componon 28mm f4 Cylinder Lens

Good to very good sharpness center to corner.
Corner shading.
Some field curvature.

Scheider Kreuznach Componon-S 50mm f3.5 Cylinder Lens +
Scheider Kreuznach Componon 28mm f4 Cylinder Lens

Very good to good sharpness center to corner, edge to edge.
Some corner shading.
Some field curvature.

Suggestions, comments welcome.

Robert

Lou Jost
Posts: 5948
Joined: Fri Sep 04, 2015 7:03 am
Location: Ecuador
Contact:

Post by Lou Jost »

This is another very interesting set of observations that coincides with Miljenko's tests.

Although we usually use a wide lens for the reversed front lens of a combo, a longer front lens is likely to have a flatter field. I have found that reversing a fast 100-150mm lens on an even longer lens gives very good results (always with aperture placed between the lenses).

ray_parkhurst
Posts: 3417
Joined: Sat Nov 20, 2010 10:40 am
Location: Santa Clara, CA, USA
Contact:

Post by ray_parkhurst »

Lou Jost wrote:This is another very interesting set of observations that coincides with Miljenko's tests.

Although we usually use a wide lens for the reversed front lens of a combo, a longer front lens is likely to have a flatter field. I have found that reversing a fast 100-150mm lens on an even longer lens gives very good results (always with aperture placed between the lenses).
The long/longer lens combo also provides for long WD, provided the objective lens is not a standard mount prime.

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

ray_parkhurst wrote:
Lou Jost wrote:This is another very interesting set of observations that coincides with Miljenko's tests.

Although we usually use a wide lens for the reversed front lens of a combo, a longer front lens is likely to have a flatter field. I have found that reversing a fast 100-150mm lens on an even longer lens gives very good results (always with aperture placed between the lenses).


The long/longer lens combo also provides for long WD, provided the objective lens is not a standard mount prime.
That reminds me.:oops:

Planned to measure the WDs for all the combos but I was so fixated by the sharpness I completely forgot !

:?

Robert

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

If anyone has any ideas or experience in removing an aperture disk let me know.

The 28/4 has a 5mm disk.

The 50/3.5 has a 9.5mm disk.

I would like to replace the 28/4 5mm with the 9.5mm but the disks have a small bead around them.

Tried isopropyl but no effect at all, it didn't even soften the bead material.

Any ideas?
Last edited by RobertOToole on Thu Nov 01, 2018 12:32 am, edited 1 time in total.

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

Ray's advice was that the aperture disk is probably held in place with epoxy but I should/might be able to unscrew the real cell also and get the disk from the other side to push it out.

To my surprise rear cell is also removable.:roll: :oops:

It's official, Ray_parkhurst is a genius! :shock:

Thanks!

Robert

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

Update.

Good news.

The center disk sections on the industrial cylinder lenses are interchangeable.

The center disk sections on the 28-40-50mm lenses are all the same threads, length OD.

So I now have 5mm, 6.5mm and 9.5mm aperture disk sections to choose from.

On the 28mm componon I measured the disk apertures from the front and the rear with a macro lens and with focus peaking I made an image of the front lens pupil, than another of the rear pupil, being careful not to change focus, finally I made the last image of a ruler for reference being careful not to change focus/extension between frames.

5mm =
Front: 7.12 = f/3.9
Rear: 8 = f3.5

6.5mm=
Front:9.5 = f2.9
Rear: 10.5 = F2.66

9.5mm=
Front:12.3 = f2.2
Rear: 14 = f2


This makes the set of industrial lenses a lot more useful and valuable.

The industrial cylinder 28 mm version is more flexible than the consumer version since the iris is pre-set closed down from the factory. I did have two of these with a open iris design, one with a round iris and one with a hex iris, but these are pretty hard to find.

This is an example of the closed down iris on the 28mm componons that I am referring to.

Image

All of these 28mm componon are set to wide open on the aperture ring but only the iris in the center lens above actually opens all the way.

Robert

Miljenko
Posts: 171
Joined: Sat Jun 01, 2013 11:53 pm
Location: Zagreb, Croatia
Contact:

Post by Miljenko »

A valuable find, Robert. Now you just have to come to perfect combo like 2.8/50 Componon-S + Agfa 4/107. And finding the way of changing aperture masks was opening a can of worms! There are so many combinations now. It's a pitty you don't measure actual resolution; it would speed up the whole process.
Best.
Miljenko
All things are number - Pythagoras

ChrisR
Site Admin
Posts: 8668
Joined: Sat Mar 14, 2009 3:58 am
Location: Near London, UK

Post by ChrisR »

A couple of thoughts
How "good" is good, if you compare the performance against an objective of similar NA?

Does dismantling the lens and reassembling, change the performance ?

What happens if you remove the iris from a consumer f/4 28mm - can you make 'em better? :twisted:
Chris R

Lou Jost
Posts: 5948
Joined: Fri Sep 04, 2015 7:03 am
Location: Ecuador
Contact:

Post by Lou Jost »

And what happens if the aperture is put in the best place- between the lenses?

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

Miljenko wrote:A valuable find, Robert. Now you just have to come to perfect combo like 2.8/50 Componon-S + Agfa 4/107. And finding the way of changing aperture masks was opening a can of worms! There are so many combinations now. It's a pitty you don't measure actual resolution; it would speed up the whole process.
Best.
Miljenko

My idea was originally to use some common lenses and hoped for the best, I found something in a less time that I expected and the performance was a lot higher than expected.

I processed a full size file last night and at 100% the details and lack of CAs is an eye-opener, it looks more like the results from an APO objective than a real APO objective!

The problem with me starting with MTF is that I have no reference files to compare results to come to a conclusion, but with the slower old-fashioned manual method I can easily compare files.

It would be a different story of course if I had 100 MTF curves on my hard drive already.

Best,

Robert

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

ChrisR wrote:A couple of thoughts
How "good" is good, if you compare the performance against an objective of similar NA?
Didn't expect such good results so soon but now that I to consider that.

What to use to compare IQ? It doesn't help that the mag is 4.2x, almost 4.3x.

The Mity5x on a ITL with short focus is 4.3x?
Does dismantling the lens and reassembling, change the performance ?
The front and cells are sealed like a large format Nikon or Rodenstock lens so I don't think so.

Thankfully one of the lenses had a loose front cell. If I had to "break" these open with a lot of force I would never have figured out the fact that the aperture sections are interchangeable. All of the 3 lenses were only hand-tight.

What happens if you remove the iris from a consumer f/4 28mm - can you make 'em better? :twisted:
There have been some conversations on that topic on the forum over the years. I have owned a couple of wider opening 4/28 lenses and they were not any better than the f4.5 versions from what I remember but I would put my money on a stacked 4/28 vs an extended only 4/28.

Here is one of the wider 4/28 lenses next to a normal 4/28 and a 2.8/28 on the right just for reference. All the lenses are set wide-open (and I am pretty sure I lined up the apertures so they were all in focus).


Image

RobertOToole
Posts: 2627
Joined: Thu Jan 17, 2013 9:34 pm
Location: United States
Contact:

Post by RobertOToole »

Lou Jost wrote:And what happens if the aperture is put in the best place- between the lenses?
Good question.

Glad I found that the sections change out, now I can install the 10mm / f2 disk and add a smaller f2.8 disk between the lenses right?

There is a 2/35 cylinder lens on Ebay with bad corrosion, I should buy that lens and empty the center section. That might be useful later.

Thanks for the idea Lou.

Robert

Post Reply Previous topicNext topic