Morfing infinites to bellows

[seta666]

Yesterday I receved the morphanon an I did my own mount using cheap M42 chinese tubes, two 41mm flat "O" rings and a dremmel
I sanded something like 1mm from the iner part of the middle M42 tube, then I put it in (the M42 tube itsel levels the whole thing) and I used two O rings and the small tube to hold the tube lens in place
Here you have some pictures

Everything I used, note the sanded middle M42 tube

Tube lens in place and the 2 O rings


Tube lens hold in place with small M42 tube


Tube lens frame inside the big M42 tube, 2 different views

A finite picture with bellows; the corner degrade a lot




Regards

[Craig Gerard]

Javier,

Have you considered removing the cone from the equation?

Craig

[seta666]

Javier,

Have you considered removing the cone from the equation?

Craig

It is just a picture showing the tube lens on the bellows, that is the only bd mount I have at the moment (i am waiting for some to arrive). I had undertood that mitutoyo objectives needed a distance of 90mm to the tube lens. How does the distance to the tube lens affect in the final image?
I have not done any shots in a couple of months but I have things almost ready again and I am eager of trying all the stuff I have seen in the forums
Regards

[ChrisLilley]

I had undertood that mitutoyo objectives needed a distance of 90mm to the tube lens. How does the distance to the tube lens affect in the final image?

The diagram of the Mitutoyo MT1 discussed in this thread shows a tube lens to objective shoulder distance of 76.5mm, but also has a 45degree half-silvered mirror in that space.

Later in that thread a tube lens to objective shoulder distance of 15mm is shown for the MT-4, a tube lens which mounts directly on the back of the objective.

[Blame]

seta666

Great. I can't wait for my M42 tubing to arrive.

I thought you would have to sand down the 41mm thread on the lens a tad. It must have been a tight fit.

[Chris S.]

I had undertood that mitutoyo objectives needed a distance of 90mm to the tube lens. How does the distance to the tube lens affect in the final image?

Adding to Chris Lilley's observations, page 23 of the Mitutoyo manual available here shows the following diagram and math, summarizing thus: "In other words a distance (L) smaller than the specification does not affect optical performance. Contact Mitutoyo
for detailed information." ("L" is the shoulder distance between objective and tube lenses.)

[rjlittlefield]

I had undertood that mitutoyo objectives needed a distance of 90mm to the tube lens. How does the distance to the tube lens affect in the final image?

Adding to Chris Lilley's observations, page 23 of the Mitutoyo manual available here shows the following diagram and math, summarizing thus: "In other words a distance (L) smaller than the specification does not affect optical performance.

Taken literally, that part about "does not affect" may be true for Mitutoyo's own tube lenses, but it is not true for other lenses used in the same way.

For other lenses, quality is often better with a shorter distance. This is because shorter distance avoids sending light through the edges of the tube lens, which for cheap lenses are not corrected as well as the center. (The edges of Mitutoyo's tube lenses must be quite good, consistent with their high price.)

--Rik

[Craig Gerard]

How does the distance to the tube lens affect in the final image?

I am also waiting for the jinfinance adapter to arrive. I used the BD cone adapter on one occasion with the Mitutoyo 10X 0.28 and vignetting was a problem on a 135mm (prime) tubelense which had previously not exhibited vignetting. Chris' and Rik's responses explain why this may have occurred and also highlight other important aspects of objective and tubelense interaction.

Craig

[pludder]

It should be noted that the Br5 has an external 52mm thread, so I am now looking for 52 mm female to 52 mm female adapter or thin tube so that Infinite adapters can be easily used,such as M52 male thread to M25 x 0.75 (nikon CFI microscope objective) adapter

I use a Nikon BR3 + a K2 for a female -> female 52mm, that gives an adapter ~ 20mm thick if that is ok for your use.

[Len Willan]

Thank you pludder for your suggestion of using “Nikon BR3 + a K2 for a female -> female 52mm, that gives an adapter ~ 20mm thick”
The 52mm thread on a Nikon Br2 has a depth of 3mm.
The jinfinance M52 male thread to M25 x 0.75 (nikon CFI microscope objective) adapter thread also has a depth of 3mm.
Craig’s previous post here suggested using a 55-52 Step Down Filter Ring Stepping Adapter.I have now found out that some do not have a step, but have a complete inner thread (and only cost $3.48 on Ebay) and the total female thread is 5mm.
A 52mm filter with the glass removed can be added if more stand off is required between the morfanon and the Nikon CFI Plan Achromat Objective 10x/0.25 WD 10.5.

I am looking forward to the arrival of a New Nikon10x/0.25 WD 10.5.objective and the 55 >52 mm step ring.

[Craig Gerard]

...snip...I have now found out that some do not have a step, but have a complete inner thread

Yes, they are the ones to use

I'm using one right now in combination with an M42 helicoid (and a BR2A and a PB4 bellows) and a morfanon inside the helicoid. The BR2A is connected to the M42 helicoid using a similar 'inner-threaded' adapter.

Regarding the morfanon...which end is the 'top'?


Craig

[Blame]

Craig

Morfa found the lens to be much the same both ways round.

I am fairly confident it is an achromatic pair. As a rule of thumb they work best with the rounded side to infinity. That would be the end with the screw thread pointing towards the objective. Just the way Morfa tested it.

[Craig Gerard]

Thanks Blame,

Yes, I have looked at the configerations. I currently have the morfanon positioned with threaded end facing the objective.

Like this:




Craig

[Blame]

Craig

I just had a look at seta666's picture taken using a morfanon as a camera lens.

http://seta666.pixa.us/images/19219901/ ... 2-mount006

It is a rotten lens when not stopped down.

The point is you really want to only use the center. If you use 100-200mm between morfanon and objective the light is going to spread out.

I don't know the specs of your nikon but if you use a lower power mitutoyo and uncropped sensor (37mm diagonal) and 170mm tube length the maths looks like this:

For 0mm separation: 11.2mm diameter of morfanon used
For 100mm: 11.2+ 37x100/170=11.2+21.8=33mm

Looks like it will not only be using the whole lens - it should be starting to vignet too. I hadn't realized how much shortening the tube lens and using an uncropped sensor altered the maths.

Clearly you need to get the lens & objective tight together. Every 5mm spreads the beam edge by about 10%.

[Craig Gerard]

Thanks Blame,

Yes, you highlight a good point with regard to the morfanon and Javier's image provides a good example of the sharp area.
I'll tweak my arrangment so that only the centre of the morfanon is utilised.

*I now have the threaded end of the morfanon approx 3mm from the rear of the microscope objective.

Craig