www.photomacrography.net :: View topic - Lenses for use at 4-5X on an APS-sized sensor
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 
Lenses for use at 4-5X on an APS-sized sensor
Goto page Previous  1, 2, 3, 4, 5  Next
 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Equipment Discussions
View previous topic :: View next topic  
Author Message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 20182
Location: Richland, Washington State, USA

PostPosted: Wed Feb 29, 2012 11:05 am    Post subject: Reply with quote

Yes, you do reverse the EL Nikkors. Likewise for all other enlarging lenses, which are designed to take a small piece of film and enlarge it to make a bigger print. In the photo, reversed would be up-side toward the subject. Takes a 40.5 mm ring for the one shown.

About the reversed 18-55 Canon kit lens, I'm not sure where that would end up in the rankings because I haven't shot comparable targets. Based on memories of general appearance at actual pixels, I'd say it's close to rock bottom, probably at the bottom for central sharpness. But it's certainly available and convenient, and if the sharpness is good enough to meet your needs, that combination makes it a great deal.

--Rik
Back to top
View user's profile Send private message Visit poster's website
Pau
Site Admin


Joined: 20 Jan 2010
Posts: 4859
Location: Valencia, Spain

PostPosted: Wed Feb 29, 2012 11:12 am    Post subject: Re: dark corners Reply with quote

Tim M wrote:
Hi Rik,

I tried a Nikon CFI 10x Plan like yours on a Canon 55-250 f/4.0-5.6 lens and was seeing significant dark corners down at 100mm and even 135mm (but it sure rocks up at 200-250mm!). It's bad enough at 100mm that the field is effectively reduced by over 30%. I think I had the lens wide open. Would you expect that result, or am I possibly doing something incorrect? Would a faster lens help?


In my test of this objective on a Canon EF 70-200 f4 L IS I find it good up to 140mm, about 7.2X

Tim M wrote:
Quote:
As a cheaper option there are many 100mmm enlarger lenses


Thanks Chris,
Silly question but do I reverse those enlarger lenses, as I do when using the 50mm & 80mm el Niks directly for macro? (I assume not). That's gonna be a strange looking setup on the camera! Smile And I assume to mount the enlarger lens as close to the camera as possible?


In principle the tube lens needs to be focused to infinite, so a 100mm enlarger lens will need a lot of bellows extension. Better not reversed
_________________
Pau
Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 8406
Location: Near London, UK

PostPosted: Wed Feb 29, 2012 11:36 am    Post subject: Reply with quote

It was a suggestion I haven't actually tried - I should have said Embarassed . The enlarger lens should be best when oriented the normal way round, focused at infinity. That means so a rather short bellows on a camera, or your luckiest combination of extension tubes.
Folk hereabouts have used copy lenses and longer lenses with success, but nothing quite so short, as far as I can remember.
The gotcha may be that NO enlarger lens is designed to work at infinity, but "we" don't have too much idea how much difference that's going to make. If you search here on "morfanon" you'll find tales of a rather poor lens working at infinity, which turned out to be OK as a tube lens.

I'll try to find time to try something.

The set focus distance of the enlarger lens used like this may not be ultra critical, it's been reported here that focusing a 200mm telephoto as "tube" lens seems to work without big problems over a useful range, so for example a stack can be compiled. I've done a stack with a 200mm lens set to 20 feet, in error. It didn't make much difference. That's nearly 5mm out!

Looking at "completed listings" there are several Rodagons and Componons at about 100 - 105mm f/5.6 for under $50.
Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 8406
Location: Near London, UK

PostPosted: Thu Mar 01, 2012 12:52 am    Post subject: Reply with quote

Well it works, with a 10x CFI on a cheap Rodagon-P 105mm. Field coverage is OK (APS-C), detail looks as though it could be nearly as good as with the micro Nkkor, but the lighting was so different I can't say more. Sandpaper is shiny! I'll have to rerun, not sure when I can do that!
Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 20182
Location: Richland, Washington State, USA

PostPosted: Mon Apr 16, 2012 8:02 am    Post subject: Reply with quote

rjlittlefield wrote:
mlackey wrote:
I know you have not tried this, but based on your experience with the 4x, would you think the 10x on a 70-200 (at 200) would yield similar results?

That's my expectation, but I'll report back when the CFI BE 10X arrives. Wink

I haven't had time yet to run a full test set on the CFI BE 10X, but I have used it for a couple of stacks and found that it works quite well when pushed down by using a short tube lens. Definitely a keeper. See HERE for an example.

--Rik
Back to top
View user's profile Send private message Visit poster's website
ray_parkhurst



Joined: 20 Nov 2010
Posts: 2432
Location: Santa Clara, CA, USA

PostPosted: Tue Apr 17, 2012 12:55 am    Post subject: Reply with quote

I've had some excellent results with a 150mm EL-Nikkor on bellows as tube lens. The 150mm has M39 mount with 52mm filter threads so is easy to adapt and fits in with my standard setup nicely. I still need to try it with my Mitutoyo 5x M Plan Apo to see how well they perform together...Ray
Back to top
View user's profile Send private message Visit poster's website
Babylonia



Joined: 20 Mar 2012
Posts: 48

PostPosted: Tue Apr 17, 2012 6:31 am    Post subject: Reply with quote

I am not familiar to stack lenses or make use as a "tube lens" for high magnifying photography yet. These solutions intrigues me. I have a bunch of enlarger lenses from about 75mm to 300mm (even must have an El Nikkor 50mm/2.8 somewhere in a box at the loft), so a nice opportunity to do something with it with these enlargement factors (at least with the more short focal lengths).

But as a stack in combination with a small finite lens (is that the right name of these microscopic lens parts?) I wonder if the image field is wide enough to cover full frame (Nikon D700). Stacking with enlarger lenses I think it is best to combine using the APO models (e.g. Rodenstock APO Rodagon-N 105mm/4.0) for less problems by colour issues.

But as normal camera lenses are better suited for use at infinity setting, maybe a better combination can be made e.g. with some (old) good camera lenses. I do have a manual Micro Nikkor 105/2.8 known as very good at infinity (as a discrepancy to its macro use), or Voigtländer Apo Lanthar 90mm/3.5
When used as a stack, I suppose the enlarger or camera lens has to be used wide open? (I guess optical path is restricted by the little lens stacked in front ?).

Many options to consider an test.

As an option too in the range of about 5x enlargement (but IMO not the best one), see some test results of a reversed manual Nikkor 24mm/2.8 AIS lens, I wrote at another forum. << Translation by Google, so sorry for strange words. >>
_________________
Greetings from Holland
Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 20182
Location: Richland, Washington State, USA

PostPosted: Tue Apr 17, 2012 9:34 am    Post subject: Reply with quote

Babylonia wrote:
But as a stack in combination with a small finite lens (is that the right name of these microscopic lens parts?)...

Not the right name for that use. "Finite" microscope objectives are designed to be used on empty extension; "infinity" objectives are designed to be used with another lens to finish the image formation. See the FAQ: How can I hook a microscope objective to my camera? for more information about that.

Quote:
I wonder if the image field is wide enough to cover full frame (Nikon D700).

Most microscope objectives will not cover full frame when used at rated magnification. The Nikon CFI series does cover, however. Also, if you adjust the magnification so that the same size subject is being photographed, then coverage mostly does not depend on sensor size. With infinity objectives, this is done by increasing the length of the tube lens. Example: 10X on a 22 mm sensor covers 2.2 mm of subject using a 200 mm tube lens. On a 36 mm sensor, to cover 2.2 mm of subject you would need 16.36X with about a 327 mm tube lens.

Quote:
But as normal camera lenses are better suited for use at infinity setting, maybe a better combination can be made e.g. with some (old) good camera lenses.

Yes, this can significantly improve the corner performance. See HERE for illustration.

Quote:
When used as a stack, I suppose the enlarger or camera lens has to be used wide open? (I guess optical path is restricted by the little lens stacked in front ?).

Yes, at high magnification one should stop the short lens stacked on front. See FAQ: Stopping down a lens combo for more information about that.

--Rik
Back to top
View user's profile Send private message Visit poster's website
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 8406
Location: Near London, UK

PostPosted: Tue Apr 17, 2012 9:52 am    Post subject: Reply with quote

Leon
For tube lenses ( used with infinite objectives). you raise again some common questions, only partly covered in our FAQ, which has sprawled somewhat.

This is my current understanding! -

I don't remember anyone trying any prime(non zoom) lens with an objective screwed to the front, saying that it didn't work.
If you use a "tube" lens which is too short, you'll get poor resolution in the corners, or excessive darkening, lateral chromatic aberration ( common) or they'll be cut off altogether. Often you can improve the lateral CA considerably, in post processing

But almost all of that is dependant on the objective. If you move the objective further out from the front of the tube lens, you get more vignetting, and perhaps other effects, for better or worse. ( I haven't tried very much).
The optic path means that you're (mostly?) only using the middle of the tube lens, so it makes little or no difference if you close the diaphragm, as long as you don't cause more vignetting.
Some lenses have small reflective surfaces inside which are covered up if you shut the lens a little, some users report improvements in peripheral chromatic affects, but they'ye way down in significance, compared with the objective's performance.

Sticking my neck out a bit, I believe ANY enlarger lens in the 90 - 240 range works well or very well, unless, at the shorter end, you get objective-induced vignetting. Genuine Nikon/Mitutoyo tube lenses Are reported as being slightly better, but not a lot, compared to a good 210mm enlarger lens, for example.

Certainly Nikon 100mm f/2.8, 135mm f/2.8 or f/3.5, 180mm f/2.8, and 200mm f/4 all "work", as do enlarging Rodagons, Componons. Nikkors, Fujinon and doubtless other good quality lenses.
A Micro-Nikkor 200mm, which does NOT work particularly well at infinity, was reported as not being as good as alternatives, as a tube lens.
Most of the "cheap" enlarger lenses were generally under 100mm unless rather old, so fortuitously, we aren't looking at them.

Some of the above I've tried myself, some is remembered from members' posts or PMs.

It seems reasonable to suggest that each objective has a "good field of view", subject side. EG for a Nikon CFI 10x NA 0.25 it's (from memory) just over 5mm. That means that if you use it with a tube lens at 10x, it'll cover 24 x 36mm ( diameter approx 43mm). If you use it with a 100mm tube lens it'll just cover APS-C, which is about 27mm diameter.

Measuring the FOV is somewhat subjective, because it depends what you accept. A plain "plan" objective's performance fades away, starting even within the designed circle of use, whereas a plan apo's likely to "fall off a cliff" at a more definite diameter. It depends on the subject too of course - often the edges of the frame are of high contextual interest, but don't need to be nearly as sharp as the middle.

Some users may object to some of what I've just wriitten - fine, let's hear it!

----Other thoughts.........

The fact that the tube lens "doesn't matter much" is something I have difficulty understanding. The cheap and simple "morfanon" ( a "surplus" lens which was found happens to work quite well as a tube lens) is a pretty bad camera lens. Then why does it work well?
I would love someone with a genuine tube lens to poke it out of the window and photograph a distant electricity pylon or a street light at night.

A 10x objective on a shorter tube lens is apparently outresolves a 4 micron pixel-size sensor. But the same short lens used on a real subject, would not, at the same effective aperture. That leads me to think I'm missing something.

--

Ray diagrams of tube lenses in action ( I'll add Rik's links when I find them) show that the rays do not go the ways they would if the tube lens were used as a camera lens. So when using a camera lens ( or enlarger lens) as a tube lens, does this mean that aberrations aren't getting corrected as the lens designer intended? This could happen if the degree of an aberration introduced, and then corrected in design, varies with the distance off-axis.
Back to top
View user's profile Send private message
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 8406
Location: Near London, UK

PostPosted: Tue Apr 17, 2012 10:09 am    Post subject: Reply with quote

If you want to reverse a short lens on bellows, or on a long lens, the ones recommended in the (old manual focus) Nikon line-up were the 28mm f/2.8, but only the EIGHT element one, not the 5 element one, and the 20mm f/2.8.

I think that's because the 28/8 is a particularly good lens which focuses close ( so appropriate for use on bellows reversed) and the 20mm is, well, 20mm, so it's "powerful".
I can confirm the 28/8 is better than the 28/5 when reversed, but as I have one or two other lenses designed to work in the same magnification range, I don't do that any more.

Recollections of the 20mm and 24mm lenses reversed are of nasty hot-spots in the centre, but that could have been due to internal reflections I didn't know about back then.
Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 20182
Location: Richland, Washington State, USA

PostPosted: Tue Apr 17, 2012 10:09 am    Post subject: Reply with quote

ChrisR wrote:
Some users may object to some of what I've just wriitten - fine, let's hear it!

Looks good to me.

Quote:
The fact that the tube lens "doesn't matter much" is something I have difficulty understanding. The cheap and simple "morfanon" ( a "surplus" lens which was found happens to work quite well as a tube lens) is a pretty bad camera lens. Then why does it work well?

Have you tried stopping down a morfanon to around f/20? That's the effective aperture of a 10X NA 0.25 objective at rated magnification.

Quote:
I would love someone with a genuine tube lens to poke it out of the window and photograph a distant electricity pylon or a street light at night.

I can do that, perhaps later today.

Quote:
A 10x objective on a shorter tube lens is apparently outresolves a 4 micron pixel-size sensor. But the same short lens used on a real subject, would not, at the same effective aperture.

Do you have a reference to those results? In the tests that I've run, I don't recall seeing any extra resolution appear.

Quote:
Ray diagrams of tube lenses in action ( I'll add Rik's links when I find them) show that the rays do not go the ways they would if the tube lens were used as a camera lens.

Probably this one: http://www.photomacrography.net/forum/viewtopic.php?p=58595#58595.

--Rik
Back to top
View user's profile Send private message Visit poster's website
ChrisR
Site Admin


Joined: 14 Mar 2009
Posts: 8406
Location: Near London, UK

PostPosted: Tue Apr 17, 2012 10:22 am    Post subject: Reply with quote

Quote:
Quote:
A 10x objective on a shorter tube lens is apparently outresolves a 4 micron pixel-size sensor. But the same short lens used on a real subject, would not, at the same effective aperture.


Do you have a reference to those results? In the tests that I've run, I don't recall seeing any extra resolution appear.

Fair question - I'm going from memories of fairly crummy lenses I've had a go with, as tube lenses, with the Nik 10xCFI. The resulting pixel-level detail is surprising.
I'll go a few lenses at a pylon, at f/22.

Quote:
Have you tried stopping down a morfanon to around f/20?

No. Begs another question...
We often see magazine lens-test say a lens doesn't do well at f/22. My slight reaction has been " Rolling Eyes ", as I've not to my knowledge got any lens which is much good at f/22, I assumed because of diffraction limiting them all. Perhaps some really are a lot better than others.
Something simple like a Tessar, might be revealing.
Back to top
View user's profile Send private message
Charles Krebs



Joined: 01 Aug 2006
Posts: 5805
Location: Issaquah, WA USA

PostPosted: Tue Apr 17, 2012 12:43 pm    Post subject: Reply with quote

Chris,
Quote:
Some users may object to some of what I've just wriitten - fine, let's hear it!

Quote:

A Micro-Nikkor 200mm, which does NOT work particularly well at infinity, was reported as not being as good as alternatives, as a tube lens.


Not sure if this is an "objection" but I think there may be a significant difference between the older 200mm Micro Nikkor (1:2) and the current (1:1) version in this regard. I've had both (still own the newer version) and the older one was decidedly not as good when used "normally". I have used the current 200mm Micro Nikkor as a tube lens a bit, and founds the results quite good. If I recall correctly Chris S was not enthralled with his results using it, and I think someone had tried the older version with less than stellar results. So while I would not run out and get one (current version) to use as a tube lens I would certainly try it if I already owned one. (And it is a very good macro lens when used as such)
_________________
http://www.krebsmicro.com
Back to top
View user's profile Send private message Visit poster's website
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 20182
Location: Richland, Washington State, USA

PostPosted: Tue Apr 17, 2012 3:05 pm    Post subject: Reply with quote

rjlittlefield wrote:
ChrisR wrote:
I would love someone with a genuine tube lens to poke it out of the window and photograph a distant electricity pylon or a street light at night.
I can do that, perhaps later today.

See http://www.photomacrography.net/forum/viewtopic.php?t=16718.

--Rik
Back to top
View user's profile Send private message Visit poster's website
Babylonia



Joined: 20 Mar 2012
Posts: 48

PostPosted: Tue Apr 17, 2012 4:35 pm    Post subject: Reply with quote

Thanks rjlittlefield and Chris for the extensive reactions and explanation. More and more I do understand the backgrounds.

I did found a source with a test of 12 lenses at 5x
I guess it is known by many of this forum:
http://www.macrosmuymacros.com/index.php?option=com_content&view=article&id=5&Itemid=25&lang=en
The site do give very useful information to several subjects about macro / micro and a gallery of very nice images.

Looking to these tests it seems a combination of one of those little microscope lenses "alone" (e.g. JML 21mm/3.5) or as a stack using a Nikon CFI 10X Plan + long focal length lens is the best solution.

Disadvantage of these microscopic lenses (or as a stack with a tube lens) seems to be the very short working distance.
Has anybody experienced the quality in using more long enlarger lenses reversed at a long bellows (e.g. using a bellows camera as Sinar) to this 5x enlargement value? I guess it still doesn't give the best quality as the results of e.g. a 50mm reversed EL Nikkor as tested at the first message is not that best, but also the test of the above link to an Apo Rodagon 50mm doesn't give the results as expected.
_________________
Greetings from Holland
Back to top
View user's profile Send private message
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 Previous  1, 2, 3, 4, 5  Next
Page 3 of 5

 
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