Search found 3436 matches

by ray_parkhurst
Wed Mar 06, 2024 11:22 am
Forum: Equipment Discussions
Topic: What features and comforts would your hypothetical dream camera system have, based on your needs?
Replies: 11
Views: 433

Re: What features and comforts would your hypothetical dream camera system have, based on your needs?

I'd like to have the following camera: 40x40mm sensor. This allows use of the many high quality lenses with 62mm image circles out to the corners. I want the sensor to be square since all my published images are square. I do stack and stitch now to end up with essentially a 36mmx36mm sensor, but it ...
by ray_parkhurst
Tue Feb 27, 2024 9:30 am
Forum: General Discussion Forum and Community Announcements
Topic: Cell Phone maximum magnification
Replies: 1
Views: 390

Re: Cell Phone maximum magnification

Hello, There are different add on lenses for cell phones to make macro world vision possible. I wonder - instead of buying a pre-built attachment, my I use quality lens to get even better result? What is the max magnification I can achieve? What other factors do I need to consider? Thank you in adv...
by ray_parkhurst
Sun Feb 25, 2024 7:24 pm
Forum: Equipment Discussions
Topic: Lens with fungus and effect on image quality
Replies: 18
Views: 592

Re: Lens with fungus and effect on image quality

After f/16 I see the dirt on the sensor... but no hint of any of the strange shapes on the glass... You will never see the shapes on the glass, because the lens surfaces will never be in focus enough to see them. This is why you can have scratches, chips, etc on a lens and they will never show up a...
by ray_parkhurst
Sun Feb 25, 2024 3:51 pm
Forum: Equipment Discussions
Topic: Lens with fungus and effect on image quality
Replies: 18
Views: 592

Re: Lens with fungus and effect on image quality

I have been thinking about using a burning laser (like the kind used to engrave stuff) to burn off the fungus from internal elements. I've tried it a little bit but it is tricky since reflective surfaces on the lenses can send the laser into your eyes, burning off your retina instead of the fungus....
by ray_parkhurst
Sun Feb 25, 2024 3:16 pm
Forum: Equipment Discussions
Topic: Lens with fungus and effect on image quality
Replies: 18
Views: 592

Re: Lens with fungus and effect on image quality

I've compared a few lenses with mild fungus to their pristine counterparts, and saw no effect. Never tested anything with as much as the one shown above though. Also have purchased a few lenses that had mild surface fungus, and found it usually cleans off quite easily just with moisture from breathi...
by ray_parkhurst
Sat Feb 24, 2024 8:05 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Mitutoyo 10x e 5x e Sony A7rV
Replies: 11
Views: 449

Re: Mitutoyo 10x e 5x e Sony A7rV

It doesn't take huge misalignment of the front standard to mess things up. 1 degree will produce a 3.5mm shift on 200mm extension. You could try tweaking the bellows a bit to see if you can improve/degrade the decentering. Even on fairly stiff bellows it's possible to move 1 degree without doing dam...
by ray_parkhurst
Tue Feb 20, 2024 7:32 pm
Forum: General Discussion Forum and Community Announcements
Topic: SF Bay Area Electronics Swap
Replies: 3
Views: 3117

Re: SF Bay Area Electronics Swap

I'm getting anxious about the next Electronics Swap, scheduled for March 10. It's going to be at West Valley College, same as all of last year. It's an excellent location, and hopefully will stay there for a long time to come. 6AM start time, but most folks are not set up until 7AM or so. That won't...
by ray_parkhurst
Tue Feb 20, 2024 8:41 am
Forum: Equipment Discussions
Topic: Sharpest aperture for a given macro lens
Replies: 35
Views: 1434

Re: Sharpest aperture for a given macro lens

Interesting information about what you describe. It may be confusing that I did a “quick & dirty” test, and used some coins as objects to be photographed. (Maybe subconscious inspired by examples here on the forum? 8) ) Indeed, by that it comes down, “how” the coins are illuminated by the light shi...
by ray_parkhurst
Mon Feb 19, 2024 7:56 pm
Forum: Equipment Discussions
Topic: Sharpest aperture for a given macro lens
Replies: 35
Views: 1434

Re: Sharpest aperture for a given macro lens

I've played around with stitching coin images using a few methods. The differences mainly come down to lighting. Lighting on full coins is critical for things like luster and color, but on detail shots the most important thing is contrast on local surface features to best show the details. I started...
by ray_parkhurst
Wed Feb 14, 2024 8:29 pm
Forum: General Discussion Forum and Community Announcements
Topic: Highest Serial Number 105PN?
Replies: 70
Views: 20937

Re: Highest Serial Number 105PN?

Here's another beautiful 105PNA from Japanese eBay seller. Great price for the condition IMO.

Serial number is 1310

https://www.ebay.com/itm/395198303329
by ray_parkhurst
Wed Feb 14, 2024 8:24 pm
Forum: Equipment Discussions
Topic: What are these?
Replies: 9
Views: 465

Re: What are these?

That would fit a 28mm inner diameter photoport on older microscopes. I think Leica S or M microscopes had those? So yeah, most likely relay lenses for microscope photography. EDIT: https://www.naturamediterraneo.com/Public/data9/Guido%20Gherlenda/phototubes.pdf_201422202543_phototubes.pdf "American...
by ray_parkhurst
Wed Feb 14, 2024 5:34 pm
Forum: Equipment Discussions
Topic: What are these?
Replies: 9
Views: 465

Re: What are these?

I can imagine projection eyepieces looking like these. The front cylinder would fit standard eyepiece tube, and the optics would intercept the light before it focuses at the standard place, and redirect it to focus farther back and bigger. But this is speculation. I have never seen anything that lo...
by ray_parkhurst
Wed Feb 14, 2024 12:11 pm
Forum: Equipment Discussions
Topic: What are these?
Replies: 9
Views: 465

What are these?

They look like tube lenses of some sort but they are not converging. Mount diameter is 52.5mm.
DSC_6170_2.JPG
DSC_6171_2.JPG
by ray_parkhurst
Tue Feb 13, 2024 1:12 pm
Forum: Equipment Discussions
Topic: New 2-5x 25mm macro from AstrHori, potentially sharper than the laowa?
Replies: 9
Views: 652

Re: New 2-5x 25mm macro from AstrHori, potentially sharper than the laowa?

mkbn wrote:
Tue Feb 13, 2024 11:36 am
Which would be neat! I really love mine and I got it used at an OK price,
It was just released and you were already able to buy it used? That seems odd. Why did the seller let it go?
by ray_parkhurst
Tue Feb 13, 2024 1:07 pm
Forum: Equipment Discussions
Topic: Sharpest aperture for a given macro lens
Replies: 35
Views: 1434

Re: Sharpest aperture for a given macro lens

The presumption that f5.6 is best at 1:1 may not be correct. Macro lenses are generally optimized for their highest magnification, so it may be that you get better performance at wider aperture than you would when doing portraits. There is also the question of what "best performance" means. Some loo...