[yeatzee]

With the creation of the macro lens club there was still a grey area left untouched: A place us less conventional macro shooters could post our photo's and equipment setups. Photographs taken with macro lenses by themselves do not belong here. Instead, this is a place for photographs taken with reversed lenses, stacked combinations of lenses, etc. Basically, macro by any means necessary

In addition, examples of your setup used to achieve the photographs are allowed, in fact encouraged This club is meant to be as informative as it is entertaining for you guys

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I'll start it off to get the ball rolling with my most recent macro shot

It was taken with my pentax F 135mm and a reversed Pentax F 28mm on the end of it, attached by a 52mm - 49mm adapter.

Contrary to common belief adding glass can in fact improve image quality, this being a case in point. The image quality is actually better when stacking these two lenses than if I were to reverse the 28mm on enough extension tubes to equal the same amount of magnification. In addition, I have found that keeping the primary lens wide open and stopping down the reversed lens gives better image quality. Therefore, for this shot, I kept the 135mm @ F/2.8 and stopped down the 28mm to F/4. Why you may ask? Quite simply because of diffraction.... for ultimate sharpness around F/5.6 in this case was best.

The picture:



Click the ^ link to view larger and see detailed crops.

Someone try THAT with a macro lens

[Ash]

It's arrived!
Thanks for hosting the thread Tanner.
Have some images in the bank to post on it soon, but in the meantime, let's see those extension tubes and reversing rings being put to use!
Look forward to seeing the images in this thread.

[dadipentak]

Someone try THAT with a macro lens

No--I'm not even going to try. It takes skill, work and passion to create something like that. All I've got is macro lenses.

[newarts]

....
Contrary to common belief adding glass can in fact improve image quality, this being a case in point. The image quality is actually better when stacking these two lenses than if I were to reverse the 28mm on enough extension tubes to equal the same amount of magnification........:

I hope it is appropriate to discuss technique/theory rather than posting photos here.

What you say about reversed stacked lenses being better than either lens by itself makes good sense in theory I think.

I base what I say largely on conjecture rather than direct knowledge of real camera lens design although I've seen good support of that conjecture in what I've read.

The basic idea is that lenses for normal (ie. low magnification) use are designed such that a far away subject yields a good image at the sensor. For example, I have read that it is common for lenses to be optimized for operation at the hyperfocal distance.

The key principle is that since light doesn't know which direction it is traveling trough a lens, light shined backwards from a lens' image plane exits the front of the lens bound for focus at a far-away subject plane.

When lenses are reversed and stacked, light from the subject (corresponding to the image plane of the first lens in the chain) exits the lens as though it were coming from a far away subject. The second lens in the chain therefore receives the light it was designed for and can create an optimum image.

Doubling the number of optical surfaces might lead to extra flare, but that is an entirely different aspect of lens performance and does not alter the earlier conclusion. A reversed lens pair could have good flatness and resolution while losing contrast due to flare.

A first guess is that the best aperture for the combined lenses would be that each lens should be set at its own best aperture; this could be easily tested in practice (HINT) and is consistent with Yeatzee's observations.

I look forward to comments.

Dave

PS I think counter arguments based on overall magnification may be valid; ie the optimal performance for a lens assumes the image plane is close to the lens' focal distance.

However a reversed stack of identical lenses must exactly compensate for each other at 1:1 magnification; at 1:1 magnification what originates at the subject plane must be exactly that received at the image plane due to the stack's symmetry (even for bad lenses in principle).

For completeness:
Yeatzee's stacked lenses had an effective focal length of about (I'll assume a spacing of about 5mm between front focal distances) of:

f ~ 135*28/(135 + 28 +5) = 22.5mm.

Therefore the overall f-number of the combination was a factor of 22.5/28 (about 80%) of that set on the 28mm lens barrel.

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Last edited by newarts; 05-08-2011 at 05:15 AM.

[GerryJM]

I have started experimenting with several old El-Nikkor enlarger lenses that I still have from my film darkroom days. I have a 50 mm f/4, an 80 mm f/5.6 and a 135 mm f/5.6. Just bought a 39 mm to 42 mm adapter and am all set to try them out on my old Pentax M42 bellows.

[yeatzee]

I have started experimenting with several old El-Nikkor enlarger lenses that I still have from my film darkroom days. I have a 50 mm f/4, an 80 mm f/5.6 and a 135 mm f/5.6. Just bought a 39 mm to 42 mm adapter and am all set to try them out on my old Pentax M42 bellows.

I just got lucky a couple of days ago and got an el nikkor 50mm f/2.8 N on ebay for $20 can't wait to compare it to my favorite m 50mm f/1.7 reversed

Definitely enlarging lenses are welcome, straight on tubes/bellows or reversed like I plan to do.

@ ash: no problem im looking forward to seeing your images

@ newarts: on my phone so my response is going to have to wait hahaha

[yeatzee]

"massive wall of text"

Ok Basically (and I apologize my responses are always so small in comparison ) what I said is based off of my own experience and the wonderful photomacrography forum I am a part of.

Im thinking the combination is better in much the same way some microscope objectives need correcting lenses to work half decently. Without them they can be horrible IQ wise, yet with they are fantastic. Another example is infinite objectives that need a separate lens to be stacked with. The F 135mm perhaps acts as a correcting lens for the reversed 28mm? Whatever it is, the results speak for themselves.

[newarts]

Ok Basically (and I apologize my responses are always so small in comparison ) what I said is based off of my own experience and the wonderful photomacrography forum I am a part of.

Im thinking the combination is better in much the same way some microscope objectives need correcting lenses to work half decently. Without them they can be horrible IQ wise, yet with they are fantastic. Another example is infinite objectives that need a separate lens to be stacked with. The F 135mm perhaps acts as a correcting lens for the reversed 28mm? Whatever it is, the results speak for themselves.

Sorry about the massive wall of text.

It was a rational for why reversed non-macro lens pairs should correct for each other & outperform either lens when used alone for macros. It also predicted superb performance for a reversed stack of identical lenses at 1:1.

I have a habit of trying to understand why something is true rather than just accepting it because deeper understanding may result. I write the reasoning down to record it for myself as well as to try to get critical input from others and to sell the idea.

I forget that such tomes are hard to read and must seem like useless ramblings on the whole if not well written.

If you have a matched pair of lenses I hope you will try them in a reversed stack at 1:1 sometime.

[MSD]

Someone try THAT with a macro lens

What program do you use for your stacking?
I've considered doing stacking and sometimes have the time, but I'm not sure on how to make the process so fine, so smooth, rather than just changing focus a little. How do you fine focus changes for 60 shots?

Well done with it... Always nice to see a macro with this DOF.

[aliasant]

Thank you Tanner !
Finally we have a place for weirdness and experiments in the macro and maybe micro realm

Amazing first stack you made!
Did you build a rail of some kind or how did you adjust the focus?

Im not into that extreme stacking dead things, yet.....
Im currently trying to figure out how to make my Bronica Nikkor-P 75mm f2.8 into a pentax macro beast.

I thought I would have room to place a bellows between the lens and my K-5 ( according to this list the lens needs 101.7mm) but that didnt work for infinity. I think I completely missunderstood the distance for this lens.
I did however test it and it is incredibly sharp and has an equally nice bokeh so I just have to make it work somehow.
I will try to take an old scrap pentax lens and place the bronica in that. It might work.

It will not be for magnifications beyond 2:1 if even that since I get to close to the subject but it will be great for bugs and flowers and if I can get it to work from infinity it should make an excellent portrait lens aswell.

Heres 3 test-shots from a first brief experiment. Nothing fancy. Just to show that there are some nice possibilities here.

Nikkor-P 75mm f2.8 Bronica S2 mount on a bellows.

[yeatzee]

Sorry about the massive wall of text.

It was a rational for why reversed non-macro lens pairs should correct for each other & outperform either lens when used alone for macros. It also predicted superb performance for a reversed stack of identical lenses at 1:1.

I have a habit of trying to understand why something is true rather than just accepting it because deeper understanding may result. I write the reasoning down to record it for myself as well as to try to get critical input from others and to sell the idea.

I forget that such tomes are hard to read and must seem like useless ramblings on the whole if not well written.

If you have a matched pair of lenses I hope you will try them in a reversed stack at 1:1 sometime.

At this point, I've got way to many concepts to try and wrap my head around in regards to macro photography (just look here and you'll see what I mean: www.photomacrography.net :: Index) that Im not going to worry about something like this. I know its true because I've seen it myself.... good enough for now I'll probably come back to this some other time but right now im focused on two things: various parts of macro photography (for instance the new linear stage) and finals

I have multiple 50's but no way to stack them. Hold them together would result in to much shake to get any decent stacks going.... i'll try and rig something up over the weekend

[yeatzee]

Thank you Tanner !
Finally we have a place for weirdness and experiments in the macro and maybe micro realm


Nikkor-P 75mm f2.8 Bronica S2 mount on a bellows.

No problem

Last one looks great!

[yeatzee]

What program do you use for your stacking?
I've considered doing stacking and sometimes have the time, but I'm not sure on how to make the process so fine, so smooth, rather than just changing focus a little. How do you fine focus changes for 60 shots?

Well done with it... Always nice to see a macro with this DOF.

Combine ZM. The linear stage is the key for so many shots.

[dadipentak]

I have multiple 50's but no way to stack them.

Duct tape!

[yeatzee]

Duct tape!

Believe me, i've been down that road...




I'd rather not get more sticky residue on my lenses