Search found 1307 matches

by enricosavazzi
Sun Dec 27, 2020 9:28 am
Forum: Equipment Discussions
Topic: Sony A7R with microscope lens
Replies: 32
Views: 8420

Re: Sony A7R with microscope lens

billben74 wrote:
Fri Dec 25, 2020 6:12 am
Apologies but could someone confirm that a7R 2 also has electronic first shutter ?
[...]
The A7RII has both electronic first curtain and fully electronic shutter (which are two separate settings in the menu). Verified it just now on my A7RII.
by enricosavazzi
Fri Dec 18, 2020 1:08 am
Forum: Macro & Microscopy Articles
Topic: Some progress toward NLOS imaging
Replies: 1
Views: 744

Some progress toward NLOS imaging

Report stating that non-line-of-sight imaging is about to become usable:

https://www.laserfocusworld.com/detecto ... 0965823D2G
by enricosavazzi
Sat Dec 12, 2020 3:15 am
Forum: Equipment Discussions
Topic: Testing Olympus UPlanFL N 4x 0.13 (FN 26.5)
Replies: 26
Views: 4841

Re: Testing Olympus UPlanFL N 4x 0.13 (FN 26.5)

[...] It [SWTLU] is cheaper than the U-TLU, which surprises me. There's also a U-SWTLU-SP which is $4075 (yes, four thousand), it uses ecoglass. Not sure if there's a pictorial difference. The fact that the SWTLU is cheaper than the U-TLU is probably explained by the fact that the SWTLU is just an ...
by enricosavazzi
Thu Nov 26, 2020 11:54 pm
Forum: Equipment Discussions
Topic: Reversed wide angle vs. telephoto for w/a macro relay
Replies: 13
Views: 2517

Re: Reversed wide angle vs. telephoto for w/a macro relay

Nice, 2011 is the earliest use of M12 lenses I've seen did you invented yourself? or can we find someone earlier? For the same use I'm looking for pinhole-type objectives, with forward pupil, maybe wider and with better optics. Marco Cavina described the Zeiss "Sonderobjektiv", a pinhole lens for 3...
by enricosavazzi
Thu Nov 26, 2020 1:44 pm
Forum: Equipment Discussions
Topic: Reversed wide angle vs. telephoto for w/a macro relay
Replies: 13
Views: 2517

Re: Reversed wide angle vs. telephoto for w/a macro relay

Years ago I did some work with a relay system, which I described in my 2011 book "Digital photography for science". While the discussion in the book contains additional details, the essential components from front to rear are: - A short-focal-length "pinhole lens" in CS mount (I used both a 2.8 mm f...
by enricosavazzi
Tue Nov 24, 2020 2:36 pm
Forum: Equipment Discussions
Topic: Mitutoyo gamme NIR pour macrophotographie
Replies: 3
Views: 1312

Re: Mitutoyo gamme NIR pour macrophotographie

The M Plan Apo NIR series is corrected from 480 to 1800 nm, so they likely display chromatic aberration in the 400-480 nm range (blue and indigo). Anything above 1,000 nm likely cannot be recorded with a Bayer sensor even after removing the NIR- and NUV-cut filters of the camera, so you would be pay...
by enricosavazzi
Mon Nov 02, 2020 1:03 pm
Forum: Equipment Discussions
Topic: Review of Mitakon Creator 85mm f/2.8 1-5X Mark II
Replies: 10
Views: 3209

Re: Review of Mitakon Creator 85mm f/2.8 1-5X Mark II

I found this lens's narrative arc very strange. One kind of gets the impression this company has no idea what they're doing, but I almost never follow normal camera lens development so I don't know if this kind of thing is normal? I would not say it is normal, but it is not unheard of either, espec...
by enricosavazzi
Mon Nov 02, 2020 12:45 pm
Forum: Equipment Discussions
Topic: Review of Mitakon Creator 85mm f/2.8 1-5X Mark II
Replies: 10
Views: 3209

Re: Review of Mitakon Creator 85mm f/2.8 1-5X Mark II

The redesign caused the nominal aperture to increase from f/2.8 to roughly f/4.8-f/5.6 I would suggest the aperture decreased or was reduced. The way I use the term aperture value in the review is in the sense of f/ratio. This is the aperture as expressed in several of the geometric optics formulas...
by enricosavazzi
Fri Oct 30, 2020 2:26 pm
Forum: Equipment Discussions
Topic: Review of Mitakon Creator 85mm f/2.8 1-5X Mark II
Replies: 10
Views: 3209

Review of Mitakon Creator 85mm f/2.8 1-5X Mark II

I have written an in-depth review of the Mitakon Creator 85mm f/2.8 1-5X Super Macro (the Mark II version of this lens) because the reviews I found online do not answer several of my questions about this lens. The text is not final and the page is not yet linked to the rest of my web site, but can b...
by enricosavazzi
Wed Oct 28, 2020 12:00 am
Forum: General Discussion Forum and Community Announcements
Topic: Found mantis - now what?
Replies: 4
Views: 1636

Re: Found mantis - now what?

Mantodea are often kept as pets. There is quite a bit of advice on the web, for example https://www.keepinginsects.com/praying-mantis/care/ and links therein.
(at the above link, I could not resist laughing at the misspelling "live in desserts")
by enricosavazzi
Wed Oct 14, 2020 9:20 am
Forum: Equipment Discussions
Topic: Can I push the resolution of a 1:1 macro lens?
Replies: 23
Views: 4651

Re: Can I push the resolution of a 1:1 macro lens?

Lou Jost wrote:
Wed Oct 14, 2020 6:51 am
I added a short discussion and a couple of links about the other methods.

Thanks, that will be helpful to many.

I could not find the new additions, am I missing something?
Perhaps there is a server cache or something else that does not update immediately.
Clip0002a.jpg
by enricosavazzi
Wed Oct 14, 2020 6:32 am
Forum: Equipment Discussions
Topic: Can I push the resolution of a 1:1 macro lens?
Replies: 23
Views: 4651

Re: Can I push the resolution of a 1:1 macro lens?

[..]In the intro to the article, you mention two of the ways to get higher magnification out of a 1x macro lens, but you leave out what is potentially the best way, reversing it not on extension tubes but on a tube lens. I think it would be a more complete article if you mention that option and its...
by enricosavazzi
Tue Oct 13, 2020 12:24 am
Forum: Equipment Discussions
Topic: Can I push the resolution of a 1:1 macro lens?
Replies: 23
Views: 4651

Re: Can I push the resolution of a 1:1 macro lens?

As I explained above, with modern lenses that have floating elements, you should have used a teleconverter instead of extension tubes. Otherwise you aremoving the lens far from ist design point. I just published a page on my site dealing with tests of four legacy macro lenses with a 2x teleconverte...
by enricosavazzi
Sun Oct 11, 2020 7:28 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Effective aperture with teleconverter + macro lens
Replies: 6
Views: 2012

Effective aperture with teleconverter + macro lens

Let's see whether I understand the problem correctly, or I am making a mistake somewhere. We assume that the pupil ratio is 1 for simplicity, so the effective aperture A' is A' = A * (m + 1) where A is the nominal aperture, and m the magnification. So if we focus a lens at m = 2 by extension alone (...
by enricosavazzi
Fri Oct 09, 2020 9:37 am
Forum: Equipment Discussions
Topic: Olympus BX stage keeps drifting down, "focus shifting".
Replies: 20
Views: 3400

Re: Olympus BX stage keeps drifting down, "focus shifting".

[...] I am using BX53 stand just to clarify, very interesting pointers about provis models, well I really like 53 because it has small footprint and does not take much space on my very busy table! [...] Indeed, the Provis stand weighs north of 50 kg "naked", needs a strong table, and most functions...