Wow, that's 8.7:1. Would be good to see what they are getting.dolmadis wrote:Robert
Yes, I can see how that suggestion arose now.
I mentioned the 23mm lens because I have seen some guys in Poland on the Facebook Groups using this Reversed stacked on a Takumar 200mm f/4.
BR
John
Edit to add "Reversed"
Stacked Lens vs APO objectives at 4x with Surprising Results
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Thanks for that. I was wondering what the difference between C and CS was.ChrisR wrote:17.526mm apparently:What will be the WD for these C-mount lenses?
http://www.ikegami.com/cb/products/pdf/ ... smount.pdf
So if the front 12mm threaded portion is removed, these lenses would have ~29mm WD. That's not too bad at all.
Edited to add: I'm referring to the 35/1.8 APO
From my notes..............ray_parkhurst wrote: Wow, that's 8.7:1. Would be good to see what they are getting.
Actually one reported he used it at 3x to 8x varied by tube length without further details (I tried).
Field of view 5mm?
One had the lens mounted reverse on an RMS turret with the SMC Super Takumar 200mm f/4 mounted on to the trino.
The other custom reverse mounted the lens to a microscope tube in place of the turret where I assume that that this was an infinite microscope. His images were reported at 9x. Looked good but they were on FB format.
HTH
John
ray_parkhurst wrote:So if the front 12mm threaded portion is removed, these lenses would have ~29mm WD. That's not too bad at all.
Edited to add: I'm referring to the 35/1.8 APO
Just to make sure everyone understands "removing the threaded portion" means cutting it off, not just removing the focussing adapter.
The rear lens of the 35/2.0 APO is much closer to the rear of the lens barrel, nowhere near as much WD can be gained by hacksawing that one.
No, both are the same non apo lens in slightly differing barrels. The 09xx has a 30.5mm filter thread, the 05xx doesn't, it is designed for clamp on filters. Same for the 28/2.0, 35/1.9 and others.dolmadis wrote:Addendum
There are two main versions of the 23mm.
One with an 09xx suffix on 5mp. Could be Apo.
The other (earlier) with 05xx. 3mp? Likely non Apo.
BR
John
The apo 23/1.4 is clearly larger.
People looking for 23/1.4 Xenoplans should be wary of the 23/1.4 (4.0) variant - it is the same lens but has a fixed circular 4.0 waterhouse type stop instead of a variable aperture.
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elimoss wrote:Robert, how do you align the wafer to the sensor plane for the test. Do you use some sort of shim tape or do you need something more precise?
You are the very first person to ever ask me that!
I use Children's clay that I buy bulk on Amazon. I make 5 cone shapes to hold up a aluminum plate with the subject. Then I lower the camera rig, usually without the objective, on to the subject plate to deform the clay cones and align the plate.
Works perfectly to align the sensor and subject to about 20x or so in my experience.
Gionometers and shims also work but I found they can take 10X the effort and time for the same results.
Sometimes stupid simple is the best way
Best,
Robert
That's pretty clever!! Thanks, Robert -- I'm going to have to try something like this with flat subjects.RobertOToole wrote:elimoss wrote:Robert, how do you align the wafer to the sensor plane for the test. Do you use some sort of shim tape or do you need something more precise?
I use Children's clay that I buy bulk on Amazon. I make 5 cone shapes to hold up a aluminum plate with the subject. Then I lower the camera rig, usually without the objective, on to the subject plate to deform the clay cones and align the plate.
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I didn't invent that technique, I need to give credit to Chris R.elimoss wrote:That's pretty clever!! Thanks, Robert -- I'm going to have to try something like this with flat subjects.RobertOToole wrote:elimoss wrote:Robert, how do you align the wafer to the sensor plane for the test. Do you use some sort of shim tape or do you need something more precise?
I use Children's clay that I buy bulk on Amazon. I make 5 cone shapes to hold up a aluminum plate with the subject. Then I lower the camera rig, usually without the objective, on to the subject plate to deform the clay cones and align the plate.
Wow! I gotta try that sometimes, thanks Robert.RobertOToole wrote:elimoss wrote:Robert, how do you align the wafer to the sensor plane for the test. Do you use some sort of shim tape or do you need something more precise?
You are the very first person to ever ask me that!
I use Children's clay that I buy bulk on Amazon. I make 5 cone shapes to hold up a aluminum plate with the subject. Then I lower the camera rig, usually without the objective, on to the subject plate to deform the clay cones and align the plate.
Works perfectly to align the sensor and subject to about 20x or so in my experience.
Gionometers and shims also work but I found they can take 10X the effort and time for the same results.
Sometimes stupid simple is the best way
Best,
Robert