Search found 2834 matches

by ray_parkhurst
Sat Mar 13, 2021 4:58 pm
Forum: Equipment Discussions
Topic: Advice on 20x finite objective
Replies: 22
Views: 1252

Re: Advice on 20x finite objective

If you are interested in using the BD Plan with the built-in brightfield illumination, I have built illuminators that work very well, and interface to M42 system. You need to be a little crafty with cardboard and glue, but generally it's quite easy to build. Would be a great project for someone with...
by ray_parkhurst
Thu Mar 11, 2021 2:38 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Is Leica 1x plan achro 0.25 vignette expected
Replies: 5
Views: 624

Re: Is Leica 1x plan achro 0.25 vignette expected

The Leica system you've pictured is their "video microscope". I've owned a few of them over the years, and indeed still have one in a box somewhere. The optical system is desiged for C-mount applications, so coverage is limited. The higher mag objectives do cover more than C-mount, but the 1x and 0....
by ray_parkhurst
Sat Feb 13, 2021 8:04 am
Forum: General Discussion Forum and Community Announcements
Topic: This is what cells *really* look like. Wow!
Replies: 5
Views: 3143

Re: This is what cells *really* look like. Wow!

Very nice and well-produced video. Lots of ThorLabs product placement as well! There is of course quite a bit of CG rendering, so you have to view videos like this with a critical eye as to what was drawn by artists vs what is "real". Luckily they give you views of some of the actual images, and eve...
by ray_parkhurst
Sat Feb 06, 2021 5:48 pm
Forum: Equipment Discussions
Topic: Newport Damped Optical Posts
Replies: 38
Views: 7205

Re: Newport Damped Optical Posts

Instead of a second carriage, you could also add an idler rail and carriage. This allows you to more flexibly choose the spacing and works with rails that have less travel as the second carriage does not reduce the travel. The end result is the same, ie a much stiffer system.
by ray_parkhurst
Fri Feb 05, 2021 6:49 pm
Forum: Equipment Discussions
Topic: Awesome Objective Design PDF Online
Replies: 4
Views: 1591

Re: Awesome Objective Design PDF Online

Cool, thanks Robert.
by ray_parkhurst
Sun Jan 31, 2021 3:38 pm
Forum: Equipment Discussions
Topic: New 1.4x Lens Test Results Online
Replies: 52
Views: 9797

Re: New 1.4x Lens Test Results Online

RobertOToole wrote:
Sun Jan 31, 2021 12:29 pm
Olaf G wrote:
Sun Jan 31, 2021 6:29 am
DSC07881.jpg
I like the idea using the diagonal grid pattern, its really and quick and easy to see the area of sharpness!

Best,

Robert
I agree. The corner-to-corner tilted grid looks like a great tool for performance testing.
by ray_parkhurst
Sat Jan 30, 2021 12:52 am
Forum: Equipment Discussions
Topic: Zeiss EpiPlan HD Objectives
Replies: 2
Views: 1690

Re: Zeiss EpiPlan HD Objectives

Duke wrote:
Sat Jan 30, 2021 12:33 am
So you mean old finite one?
Opton Epiplan HD 16x 0.35 160/0 WD=1mm, f=10.4.
It does require LCA compensation (Kpl).
I have one of those somewhere in my 'garbage' box. It's not good for anything.
Bad news, but thanks...Ray
by ray_parkhurst
Fri Jan 29, 2021 9:16 pm
Forum: Equipment Discussions
Topic: Chugai KOWA Vari Focal Computar dL 105-150mm f / 4.5-5.6 Godzilla Lens
Replies: 6
Views: 1760

Re: Chugai KOWA Vari Focal Computar dL 105-150mm f / 4.5-5.6 Godzilla Lens

I wonder if the optics are the same as the other Computar 105-150 f4.5-5.6 for sale on eBay, and at Surplus Shed? I bought one of those years ago, and was not terribly impressed with the performance. I remember mentioning that I was buying one, and a forum member on a different forum took that as a ...
by ray_parkhurst
Fri Jan 29, 2021 5:58 pm
Forum: Equipment Discussions
Topic: Zeiss EpiPlan HD Objectives
Replies: 2
Views: 1690

Zeiss EpiPlan HD Objectives

Is there a good reference for these, perhaps with specs? Do they require CA correcting eyepieces? What is the WD of the 16x? I bought a 16x on a whim and am hoping it was a good purchase...Ray
by ray_parkhurst
Fri Jan 29, 2021 5:17 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: 8000ED Image Circle
Replies: 5
Views: 1726

Re: 8000ED Image Circle

A lot depends on how you define "Image Circle". Indeed a bit beyond where I tested, the lens begins to "vignette", ie the image goes dark. Some would say this is the edge of IC, but my (loose and variable) criteria is that the edge of the IC is the point where the sharpness and/or CA have noticeably...
by ray_parkhurst
Thu Jan 28, 2021 5:42 pm
Forum: General Discussion Forum and Community Announcements
Topic: Bay Area Meetup
Replies: 4
Views: 2674

Re: Bay Area Meetup

I remain interested. Maybe in the Spring.
by ray_parkhurst
Wed Jan 27, 2021 9:59 am
Forum: Equipment Discussions
Topic: New 1.4x Lens Test Results Online
Replies: 52
Views: 9797

Re: New 1.4x Lens Test Results Online

Strangely, it seems the 16-shot composite has introduced more false color, where there was less in the single image. I suspect that it has revealed more "real" color. These colors look to me like interference colors formed by small features on the subject, as opposed to false colors introduced by t...
by ray_parkhurst
Wed Jan 27, 2021 8:46 am
Forum: Equipment Discussions
Topic: New 1.4x Lens Test Results Online
Replies: 52
Views: 9797

Re: New 1.4x Lens Test Results Online

Strangely, it seems the 16-shot composite has introduced more false color, where there was less in the single image.
by ray_parkhurst
Mon Jan 25, 2021 6:45 am
Forum: Equipment Discussions
Topic: Mikrotar 90mm f1.6
Replies: 4
Views: 2146

Re: Mikrotar 90mm f1.6

What a lens, Microlithograpy? Do you any of the background on this lens Ray? Thanks for sharing that, I have never seen that one before. Best, It's the only one I've ever seen or heard of, so no info other than what the seller posted. Did a quick search for Mikrotar 2 and nothing online. FYI, for t...
by ray_parkhurst
Sun Jan 24, 2021 8:58 pm
Forum: Equipment Discussions
Topic: Mikrotar 90mm f1.6
Replies: 4
Views: 2146

Re: Mikrotar 90mm f1.6

Did someone on the forum win this auction? It was available a while back for ~$500, and the seller put it up for auction recently. I bid but not high enough. ... https://www.ebay.com/itm/Mikrotar-2-90mm-f-1-6-ultra-rare-prototype-portrait-lens-GOI-M52-/114634561338 What a lens, Microlithograpy? Do ...