Notes from Travis Olds
Travis was kind enough to send me a lot of detailed information about equipment he is using,
so I thought it would be important to record it here for posterity (not to mention my own reference).
The heart of his setup is the Mitutoyo 10x M Plan APO lens that everyone loves, along with the Raynox
DCR-250 as a relay lens. He uses a diaphragm at the Raynox to reduce spherical aberration and to give
greater depth of field when stacking steps would need to be too fine.
He also uses a bellows behind the Raynox, which would allow for control of magnification.
He and Joe have moved from the Stackshot to THK KR2606B ballscrews. These are sourced from Germany.
Joe will be able to tell me more. The Stackshot has significant side to side wobble that many people
are finding intolerable.
Here is is current list of gear all the way from the Mitutoyo to the Camera.
- mitutoyo m plan apo
- adapter: thorlabs SM1A27: www.thorlabs.com/thorproduct.cfm?partnumber=SM1A27
- iris: thorlabs SM1D25: www.thorlabs.com/thorproduct.cfm?partnumber=SM1D25
- adapter: thorlabs SM1A37: www.thorlabs.com/thorproduct.cfm?partnumber=SM1A37
- adapter: 34-43 mm step up (aka 34 male-43 female) (got it on eBay)
- conversion lens: Raynox DCR 250 in reverse
- adapter: 49 mm reversing to EOS mount (aka 49 male to EOS male) (found it on eBay)
- adapter (optional to extend length): EOS female to male
- adapter: novoflex EOS/PRO (this thing was stupid expensive thru Balpro...)
- bellows: novoflex balpro 1
- adapter: EOS/pro (again, thru Balpro)
- threaded tube adapter then to camera
Here are the links to the Thorlabs parts:
The SM1A27 is an adapter with External SM1 Threads and Internal M26 x 0.706 Threads.
The SM1D25 is an SM1 threaded Lever-Actuated Iris Diaphragm, 0.8mm to 25mm.
The SM1A37 is an adapter with External SM1 Threads and Internal M34 x 0.5 Threads.
Then he uses a 34 to 43 mm adapter to go from the SM1A37 to the Raynox.
If I didn't want the diaphragm, I wouldn't need any of this Thorlabs stuff.
What I would want is an adapter that goes from internal M25 x 0.706 threads
(that would accept the Mitutoyo) and would go to 43mm female threads.
The reverse side of the Raynox has male 43mm threads.
The other side of the Raynox (the front side) has 49mm female threads.
The DCR150 is a 4.8 diopter lens and the DCR250 is an 8.0 diopter lens.
They both have identical threading.
Can I find an adapter with M26 by 0.706 inside threads on one end and
43mm female threads on the other? Not yet I can't. There are plenty of adapters
from "Mitutoyo M26 to M42" (the old Pentax screw mount).
The Bratcam article gives a detailed list of adapters, but he uses an actual Mitutoyo tube lens
(he gives the price as $628) so this is not a road I am likely to follow.
The "Conny setup" article discusses some of the reasons for introducing a diaphragm.
Light
Travis says: "For my lighting, two schott kl1500lcd's work well.
I'm not sure more would be necessary, but the Ikea Jansjo LED clip lamps nicely augment lighting angles when needed.
I think many other people use these, too. They have good temperature that is a little warmer than the ~3300K of the schott's."
Field of view automation
Travis started the whole discussion by announcing that he was using a laser distance measuring
gadget to measure bellows extension and then automatically calculate the field of view.
He uses the Adafruit VL6180X module. It is intended for use at distances of 5mm to 100mm,
although Adafruit says it will go to as much as 200mm with low ambient light levels.
For longer distances, the VL53L0X is recommended for distances of 50mm to 1200mm.
Both are i2c interfaced, and both cost about $15.
Feedback? Questions?
Drop me a line!
Tom's Mineralogy Info / [email protected]