Search found 3413 matches

by ray_parkhurst
Thu Mar 28, 2024 11:34 am
Forum: General Discussion Forum and Community Announcements
Topic: Software LoCA analysis
Replies: 3
Views: 53

Re: Software LoCA analysis

In quick search, the most relevant thing I found was https://smallpond.ca/jim/photomicrography/focusAnalyser/howto.html . It uses a web-based tool located at https://smallpond.ca/jim/photomicrography/focusAnalyser/index.html . I checked that the tool seems to be live, but did not attempt to test it...
by ray_parkhurst
Thu Mar 28, 2024 11:29 am
Forum: Equipment Discussions
Topic: MEJIRO GENOSSEN FL0530 4.0/110 FLOAT LENS TEST IS FINALLY ONLINE
Replies: 71
Views: 3409

Re: MEJIRO GENOSSEN FL0530 4.0/110 FLOAT LENS TEST IS FINALLY ONLINE

Ray, I think you should use the procedure I described a few comments earlier (although maybe this is what you meant as well). With the subject centered, adjust focus , then (if the subject is flat and perpendicular to the camera) adjust CAS ring while watching the corners, then re-adjust the focus ...
by ray_parkhurst
Thu Mar 28, 2024 7:24 am
Forum: Equipment Discussions
Topic: MEJIRO GENOSSEN FL0530 4.0/110 FLOAT LENS TEST IS FINALLY ONLINE
Replies: 71
Views: 3409

Re: MEJIRO GENOSSEN FL0530 4.0/110 FLOAT LENS TEST IS FINALLY ONLINE

I wonder whether that's also true for the Macro-Varon or Rayfact VF - and whether there are differences between the Rodenstock HR Digaron 105mm 5.6 Float and the LINOS inspec.x float 105mm 5.6. when it comes to the settings of the float ring. I checked my 85MV on APS-C and its CAS ring seemed to be...
by ray_parkhurst
Wed Mar 27, 2024 5:24 pm
Forum: General Discussion Forum and Community Announcements
Topic: Software LoCA analysis
Replies: 3
Views: 53

Software LoCA analysis

Is there a way, using Zerene or Helicon or other software, to analyze the LoCAs of an optical system? If there is no canned method, then what is the best method to remove the RG, RB, and BG info from a given image file so that the resulting monochromatic images can be 3D analyzed? I've done RGB anal...
by ray_parkhurst
Sat Mar 23, 2024 7:13 pm
Forum: General Discussion Forum and Community Announcements
Topic: THK KR20 on eBay $40 + $5 shipping
Replies: 0
Views: 69

THK KR20 on eBay $40 + $5 shipping

Here's what seems a great price for the KR20 on eBay. This one has a fairly short throw, so would benefit from an idler. And although the auction says it includes a motor mount, the pics don't show one. The pics do show a motor coupler though. Overall for $40 + $5 shipping this is quite a deal IMO: ...
by ray_parkhurst
Sat Mar 23, 2024 4:46 pm
Forum: General Discussion Forum and Community Announcements
Topic: Loss of Robert OToole
Replies: 28
Views: 786

Re: Loss of Robert OToole

I too have been preparing for this for some time. I last met with him back in Sep or Aug, and delivered a few lenses he wanted to evaluate (the Bokina, and a few others). He seemed a lot healthier than at our previous meeting, and was actually eating pretzels with the dark beers at his favorite beer...
by ray_parkhurst
Fri Mar 22, 2024 12:12 pm
Forum: Equipment Discussions
Topic: Lens recomendation for film reproduction
Replies: 44
Views: 1016

Re: Lens recomendation for film reproduction

I think the required mag range is 0.5...1, which is within the capability of a native 55mm or 60mm Micro Nikkor, so I am questioning the need for any special mounting techniques. Why not just install a 55mm or 60mm and shoot? Quality will be superb.
by ray_parkhurst
Thu Mar 21, 2024 7:50 am
Forum: General Discussion Forum and Community Announcements
Topic: Glut of Rodenstock Apo Rodagon D 2x
Replies: 13
Views: 202

Re: Glut of Rodenstock Apo Rodagon D 2x

Well it says in the PDF about the D 2x: It is asymmetric in construction with 6 elements in 4 groups and is designed for format sizes up to 6x7 cm and scales of 1.2x to 2.5x for projection purposes or 0.8x to 0.4x for taking purposes. The size data refer to the smaller side, i.e. for projection ont...
by ray_parkhurst
Wed Mar 20, 2024 5:35 pm
Forum: General Discussion Forum and Community Announcements
Topic: Glut of Rodenstock Apo Rodagon D 2x
Replies: 13
Views: 202

Re: Glut of Rodenstock Apo Rodagon D 2x

Seems weird but the Apo Rodagon D 2X is optimized for 2X when reversed (and for 1/2x when "normal" mounted), did you know? I haven't used it for some years now but I also remember preferring the 1X model for my 18Mpx APSC https://nielspn.dk/files/apo-rodagon-d.pdf From the MTF charts - which for th...
by ray_parkhurst
Wed Mar 20, 2024 2:46 pm
Forum: General Discussion Forum and Community Announcements
Topic: Glut of Rodenstock Apo Rodagon D 2x
Replies: 13
Views: 202

Re: Glut of Rodenstock Apo Rodagon D 2x

What is "MF" ?? I should have written "MFU" for "Modular Focus Unit", Rodenstock's helicoid similar to Schneider's Unifoc. https://www.closeuphotography.com/2x-lens-test I had similar results with pretty noticeable CAs that 'calmed down' at f8. I'm not at all saying it's a bad lens but if I had to ...
by ray_parkhurst
Wed Mar 20, 2024 12:55 pm
Forum: General Discussion Forum and Community Announcements
Topic: Glut of Rodenstock Apo Rodagon D 2x
Replies: 13
Views: 202

Re: Glut of Rodenstock Apo Rodagon D 2x

rdstk2x.jpg IF this is what u r talking about I was curious about the adapter, not so much about the lens and I got 1 of the 2 available. I thought if the adapter is something like the unifoc it will be usable for other lenses too... I got the 1x Rodenstock and it is great little lens... but this o...
by ray_parkhurst
Wed Mar 20, 2024 10:00 am
Forum: General Discussion Forum and Community Announcements
Topic: Glut of Rodenstock Apo Rodagon D 2x
Replies: 13
Views: 202

Re: Glut of Rodenstock Apo Rodagon D 2x

Hi Ray I was curious about the reference you made about a modular focus unit with the lens so I ran a search. I think that I found an example but could not be sure what the mount actually was but then I noticed “out of stock” !! Best, John I just looked and can't find the auctions with the presumed...
by ray_parkhurst
Wed Mar 20, 2024 7:15 am
Forum: General Discussion Forum and Community Announcements
Topic: Glut of Rodenstock Apo Rodagon D 2x
Replies: 13
Views: 202

Glut of Rodenstock Apo Rodagon D 2x

I have an active search for these and was alerted today to a glut of them available on eBay. Anyone know what's going on? Seems maybe a manufacturing line shut down?

I see a couple auctions that even appear to have a modular focus unit with the lens, all for $199. IMO that is quite a bargain.
by ray_parkhurst
Mon Mar 18, 2024 12:35 pm
Forum: Equipment Discussions
Topic: MEJIRO GENOSSEN FL0530 4.0/110 FLOAT LENS TEST IS FINALLY ONLINE
Replies: 71
Views: 3409

Re: MEJIRO GENOSSEN FL0530 4.0/110 FLOAT LENS TEST IS FINALLY ONLINE

Thanks for all these suggestions. I am thinking that focusing the rear standard (which I also prefer to do with my 5x7 large format camera) should have the advantage of keeping the front of lens to subject constant and should be better for focus stacking. ... If you decide to focus with rear standa...
by ray_parkhurst
Sat Mar 16, 2024 5:20 pm
Forum: Equipment Discussions
Topic: Lens recomendation for film reproduction
Replies: 44
Views: 1016

Re: Lens recomendation for film reproduction

JKT wrote:
Sat Mar 16, 2024 12:08 pm
About the corner softness: How are you ensuring that you film is flat?
I guess a seconday question is if all 4 corners have issues?