Search found 954 matches

by lothman
Wed Feb 07, 2024 5:01 am
Forum: Equipment Discussions
Topic: Focus again with the Canon MP-E 65mm
Replies: 61
Views: 1609

Re: Focus again with the Canon MP-E 65mm

Right now I'm undecided between the Castel-L and the Sewbo LS001. The price is close. The performance should be similar?! Will Swebo be more accurate? Is that clamp tightening knob facing forward along the rail practical to adjust? If I am missing any important aspect, please tell me. I am receptiv...
by lothman
Mon Feb 05, 2024 4:01 am
Forum: Equipment Discussions
Topic: Tell me how you can cover the magnification range from 6x to 8x?
Replies: 45
Views: 1448

Re: Tell me how you can cover the magnification range from 6x to 8x?

The option with Mitutoyo 10x or a Chinese equivalent + a 200 mm telephoto lens is not suitable for a crop sensor due to vignetting, that is, the maximum you can lower the magnification without vignetting is up to approximately 8.7x. Why pushing down on a crop sensor? You could get a used full frame...
by lothman
Fri Jan 19, 2024 11:36 am
Forum: Equipment Discussions
Topic: Macro rail assembly
Replies: 39
Views: 2280

Re: Macro rail assembly

in vertical orientation the M(A) seems to be the most important force to consider, which is 31 Newton meter for the KR20. Assuming the camera, bellows and lens weigh 5,5kg, that's roughly 54 newton, even at the fastest speed it's moving barely 1mm/s - so that's what, like 0,054 Nm? But the center o...
by lothman
Wed Jan 10, 2024 1:37 am
Forum: Beginners Micro
Topic: Down the rabbit hole… and some questions
Replies: 10
Views: 889

Re: Down the rabbit hole… and some questions

And the dust, oh yes. It is indeed a surprise how much dust accumulates - every time :roll: . This is especially true for the glass chips. I usually use a quite harsh lighting to emphasize the corners and to get a "technical" look (some kind of low key photography). Hello Matthias, nice to see fell...
by lothman
Tue Jan 09, 2024 9:53 am
Forum: Equipment Discussions
Topic: Macro rail assembly
Replies: 39
Views: 2280

Re: Macro rail assembly

Is the motor the same as the one sold on Aliexpress or is it different? there are millions off different vendors on Aliexpress, so what can I say? My motor is nothing special, you can get such motors on Aliexpress/ebay. Got for a stronger (bigger) model what your driver can handle (see in the curre...
by lothman
Tue Jan 09, 2024 9:40 am
Forum: Equipment Discussions
Topic: Macro rail assembly
Replies: 39
Views: 2280

Re: Macro rail assembly

I probably don't understand something, please explain. The motor has 400 steps of 0.9 degrees. It turns out that each step is 2.5 microns. And the manufacturer on the website https://www.mjkzz.de claims a pitch of less than 1 micron. How does this happen? It seems like the engine can’t take smaller...
by lothman
Tue Jan 09, 2024 3:41 am
Forum: Equipment Discussions
Topic: Macro rail assembly
Replies: 39
Views: 2280

Re: Macro rail assembly

probably it works as well as the THK. What helps you most is to get a version with two blocks and spindle with a a small pitch of 1 or 2mm. In order to have sufficient stroke length get a longer rail, let's say 300mm. I run a vertical THK KR2602B rail with 2mm pitch spindle together with a 400 step ...
by lothman
Sun Jan 07, 2024 4:36 am
Forum: Equipment Discussions
Topic: Lasertec 5x 0.25 HR Objective on eBay
Replies: 42
Views: 6016

Re: Lasertec 5x 0.25 HR Objective on eBay

Once I get this test done, still have to do some in-the-field images and a bokeh test, then I will move to other 90mm lenses like Tamron, Sigma, then 105mm lenses, Tamron, Sigma, Canon, Nikon etc, than 180mm. I'm actually looking forward to using some old glass, some of these I've owned before! Thi...
by lothman
Sat Dec 30, 2023 3:31 am
Forum: Equipment Discussions
Topic: 2.8x 50mm Lens Test Finally Online
Replies: 13
Views: 1090

Re: 2.8x 50mm Lens Test Finally Online

Hello Robert, thanks for another exzellent review, very appreciated. How would you rate the Laowa 2.5-5x @2.8 compared to the bunch of lenses. On my copy I found it outresolves the A7R4/5 because pixelshift captures show much more image detail. All the best in 2024 I hope you will keep up your work ...
by lothman
Sat Dec 23, 2023 4:18 pm
Forum: Equipment Exchange
Topic: Idler Rails and Assemblies
Replies: 12
Views: 3836

Re: Idler Rails and Assemblies

rjlittlefield wrote:
Tue Dec 19, 2023 8:46 pm
What are some good ways to do this?
get a THK type "B" rail with integrated idler like the THK KR2602B
by lothman
Wed Dec 20, 2023 2:30 pm
Forum: Equipment Discussions
Topic: Nikon TU Plan APO 50x/0.80 epi objective - 1st light
Replies: 4
Views: 1845

Re: Nikon TU Plan APO 50x/0.80 epi objective - 1st light

For this test, I shot a 100-image stack using 1 micron spacing. Lighting was two Trond flat-panel LED lamps close to and pointed in the general direction of the specimen (a piece of butterfly wing). I used 4-shot pixel shift mode and converted each group of four images to true-colour using Sony Ima...
by lothman
Wed Dec 20, 2023 2:27 pm
Forum: Equipment Discussions
Topic: who has the new Laowa 90mm/2,8 2:1 Macro?
Replies: 39
Views: 11640

Re: who has the new Laowa 90mm/2,8 2:1 Macro?

dmillard wrote:
Tue Dec 19, 2023 6:36 pm
A little late to the party, but thank you for this very useful information Lothar. =D>
Best regards,
David
:D
by lothman
Wed Dec 20, 2023 5:06 am
Forum: Equipment Discussions
Topic: Zeiss GF Planachromat / GF Planapochromat
Replies: 13
Views: 3999

Re: Zeiss GF Planachromat / GF Planapochromat

FotoChris wrote:
Wed Dec 20, 2023 3:31 am
This one is "just" a Planachromat though, not one of the GFs that I was looking at ;-)
yes but high NA and large working distance
by lothman
Wed Dec 20, 2023 2:58 am
Forum: Equipment Discussions
Topic: Zeiss GF Planachromat / GF Planapochromat
Replies: 13
Views: 3999

Re: Zeiss GF Planachromat / GF Planapochromat

I'm observing this one, CARL ZEISS JENA Planachromat LDN GF 40x / 0,60 oo / 1.2-A:
https://www.ebay.de/itm/194307220899

the LDN seems to be one of the latest development made under Zeiss Jena. You can take off the coverslip thickness dial and have even more WD.

But I'm too scary to invest :roll:
by lothman
Sun Dec 17, 2023 3:11 pm
Forum: Equipment Discussions
Topic: Poltergeist in my basement
Replies: 61
Views: 27813

Re: Poltergeist in my basement

Edit: I will get some pieces of polycarbonate, which has good thermal expansion resistance to make brackets for the wings and screw them on the positioning stage. The ones I currently use are not very reliable... Are you sure? Thermal expansion coefficient of polycarbonate is three time higher than...