Purple Cymbidium - three views

[Mikes]

Just playing around on a wet Friday in Tokyo with the Df and some oddball lenses.

#1 - Rodenstock 100/1.6 plus 12mm extension tube

#2 - Jupiter 12 85/2.8 plus adapter and 12mm extension tube

#3 - Leica APO 100/2.8 plus 1:1 adapter

[Andrea B.]

An interesting trio of lenses, Mike!

On extension a lot of dof is lost, but to make up for it we get a fascinating small slice of detail not usually seen.

I have not had my Rodie out for quite some time. And now that I think about it, I don't think I've ever put it on extension. This has now gone onto the ToDo list.

[Mikes]

Thanks, Andria. This flower is not an easy or even interesting subject to photograph (too velvety red), but I was curious to see what results the three lenses would produce. Overall, I much preferred the results from the Leica. I was surprised with the results from the minute Jupiter lens with its wierd protruding (and highly susceptible) rear element.

I think that the Rodenstock produces the wildest out-of-focus flower images with extension tubes - 12mm and upwards depending on flower size.

The lenses:

[Andrea B.]

Oh my - that Jupiter is a strange one for sure. How do you protect that rear element? I think it could be tricky to try to fit a lens cap over that protrusion.

[Mikes]

It is a strange lens. It came with its own unique bakelite rear lens cap and a bakelite lens case that still has the original details and price (28 roubles).

Some details are here http://cameras.alfredklomp.com/jupiter12/

Its not exactly user friendly - the aperture "ring" is inside the hood around the front element. The protruding rear element requires an extension tube (as well as the adapter) to avoid hitting the mirror or sensor. I bought it for a song, and am still playing around with it on the Df and an X-T1 to see what it can do.

The aperture ring can be seen below, with the rear lens cap alongside.

[Akira]

This is indeed an interesting comparison, Mike!

As you pointed out, Jupiter seems to perform really well, considering that it was used way out of its designed range.  You may also want to try reversing it to do some larger-than-life macro.  If its filter thread is relatively popular 40.5mm, it is easy to find 40.5-52mm stepup ring (both Kenko and Marumi makes one and readily available at large retailers in Tokyo) to mount the lens on BR-2(A).

[Mikes]

Thanks, Akira, for your suggestion. I will definitely follow that up. The challenge for me is that the filter thread is on the aperture "ring" around the front element. That won't stop me, just slow me down a bit. I will have to make sure that the aperture "ring" can carry the weight of the lens, as I don't know how robust it is.

[Akira]

Thanks, Akira, for your suggestion. I will definitely follow that up. The challenge for me is that the filter thread is on the aperture "ring" around the front element. That won't stop me, just slow me down a bit. I will have to make sure that the aperture "ring" can carry the weight of the lens, as I don't know how robust it is.

I see. That would be a problem.  Also, considering that there is very little distance between the rear element and the film plane when mounted normally on the L-mount camera, there might be too little a working distance when reversed...

By the way, if the filter thread is on the aperture ring, you could attach a 40.5mm filter without the glass to the ring, which should make the operation of the aperture much easier.

[Mikes]

You may also want to try reversing it to do some larger-than-life macro.  If its filter thread is relatively popular 40.5mm, it is easy to find 40.5-52mm stepup ring (both Kenko and Marumi makes one and readily available at large retailers in Tokyo) to mount the lens on BR-2(A).

Thanks for the suggestion, Akira. I did just that, and the aperture "ring" carried the (very light) weight of the lens without any problems.

I still have to play around with the set up, camera settings, etc., but it seems to work pretty well. Camera (Df) overexposes for some reason, though.

A couple of images of tiny green chrysanthemum from today...

[Akira]

Mike, these looks nice!  Glad to know that the lens seems to work nicely even reversed.  How long was the working distance?

[Mikes]

Thanks, Akira. I was pleasantly surprised with the results - it seems to be quite a bright lens.

The working distance for the first image was between 2 and 3 centimetres, I believe.

[Bjørn Rørslett]

Mikes: What is the thread size (rear end) for your Jupiter?  The exposed rear element needs protection when the lens is reversed and the easiest way is using standard extension rings such as M39, 42 mm, or K-rings (52 mm), fitted via a step-ring if necessary. Also facilitates making a short hood, with smaller opening, to cut off stray light and enhance image contrast. The "hood" could simply be one or a few step rings to bring the diametre of the free opening down as quickly as possible. 52->37mm rings are ideal for me, but I'm sure there are plenty of other appropriate combinations. However, do keep in mind to make the contraption as short as possible to allow better free working distance.

[Mikes]

Bjørn, its an M39 thread. You are right, the rear element does need protection from light sources as well as bumps. Thanks for your suggestions. I had been looking at using a 43 to 39 step down ring (reversed) and a light 43mm rubber hood to try to keep the weight down. Maybe using light extension ring(s) might be a better option - it will need 30mm to protect the rear element.

Mike.

[Bjørn Rørslett]

Drop the idea of a rubber hood. You simply need the smallest possible opening that will not vignette the final image. Believe me, stray light is the #1 enemy in such cases. Thus, the opening might well cover parts of the rear lens surface.

In a darkened room, shine a powerful flash light (torch) through the front of the lens and see what part(s) of the rear element that partake in illuminating the subject when you try to emulate the shooting conditions in 'macro' mode. Light as such is oblivious to its direction of travel, so just put the front of the torch where the film/sensor plane should go, and see where light hits the background at the position where your subject normally would be.  You might be amazed to  learn how much of the light arriving at the film plane (or leaving it, which is equivalent in this case) that originates (or lands) outside the subject field of view. Trim our hood accordingly to cut down on this non-image forming stray light.

[Mikes]

Thanks, Bjørn. Great idea - I'll try that in the morning....