www.photomacrography.net :: View topic - Stacking Low Cost Enlarger Lenses For High-End Image Quality
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Stacking Low Cost Enlarger Lenses For High-End Image Quality
Goto page 1, 2, 3  Next
 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Equipment Discussions
View previous topic :: View next topic  
Author Message
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 10:37 am    Post subject: Stacking Low Cost Enlarger Lenses For High-End Image Quality Reply with quote

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!




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
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 1:11 pm    Post subject: Reply with quote

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.
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 4:56 pm    Post subject: Reply with quote

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:



Upper left corner at 100%



Upper right corner at 100%



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
Back to top
View user's profile Send private message Visit poster's website
Lou Jost



Joined: 04 Sep 2015
Posts: 3769
Location: Ecuador

PostPosted: Wed Oct 31, 2018 6:23 pm    Post subject: Reply with quote

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).
_________________
Lou Jost
www.ecomingafoundation.wordpress.com
www.loujost.com
Back to top
View user's profile Send private message Visit poster's website
ray_parkhurst



Joined: 20 Nov 2010
Posts: 2374
Location: Santa Clara, CA, USA

PostPosted: Wed Oct 31, 2018 6:56 pm    Post subject: Reply with quote

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.
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 7:05 pm    Post subject: Reply with quote

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.Embarassed

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

Confused

Robert
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 7:08 pm    Post subject: Reply with quote

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
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 7:32 pm    Post subject: Reply with quote

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.Rolling Eyes Embarassed

It's official, Ray_parkhurst is a genius! Shocked

Thanks!

Robert
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Wed Oct 31, 2018 7:44 pm    Post subject: Reply with quote

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.



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
Back to top
View user's profile Send private message Visit poster's website
Miljenko



Joined: 01 Jun 2013
Posts: 130
Location: Zagreb, Croatia

PostPosted: Thu Nov 01, 2018 1:40 am    Post subject: Reply with quote

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
_________________
If your pictures are not good enough you are not close enough. - Robert Capa
Back to top
View user's profile Send private message Visit poster's website AIM Address
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 8396
Location: Near London, UK

PostPosted: Thu Nov 01, 2018 3:24 am    Post subject: Reply with quote

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 Evil
_________________
Chris R
Back to top
View user's profile Send private message
Lou Jost



Joined: 04 Sep 2015
Posts: 3769
Location: Ecuador

PostPosted: Thu Nov 01, 2018 4:29 am    Post subject: Reply with quote

And what happens if the aperture is put in the best place- between the lenses?
_________________
Lou Jost
www.ecomingafoundation.wordpress.com
www.loujost.com
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Thu Nov 01, 2018 8:27 am    Post subject: Reply with quote

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
Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Thu Nov 01, 2018 8:50 am    Post subject: Reply with quote

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?

Quote:

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.


Quote:

What happens if you remove the iris from a consumer f/4 28mm - can you make 'em better? Twisted Evil


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).


Back to top
View user's profile Send private message Visit poster's website
RobertOToole



Joined: 17 Jan 2013
Posts: 1377
Location: United States

PostPosted: Thu Nov 01, 2018 8:55 am    Post subject: Reply with quote

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
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Equipment Discussions All times are GMT - 7 Hours
Goto page 1, 2, 3  Next
Page 1 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group