Search found 4578 matches

by Lou Jost
Thu Oct 29, 2015 5:47 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Common fly, its proboscis and leg
Replies: 18
Views: 5418

Thanks Rik, that's good to know.
by Lou Jost
Thu Oct 29, 2015 2:51 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Common fly, its proboscis and leg
Replies: 18
Views: 5418

Beautiful images! May I ask why you have an extension tube in the set-up? That's something new for me. I had thought the best results would be with the tube lens focused at infinity.
by Lou Jost
Thu Oct 29, 2015 2:47 pm
Forum: Equipment Discussions
Topic: Camera for Macroscopy
Replies: 22
Views: 2283

Hmmm....mysterious....
by Lou Jost
Thu Oct 29, 2015 11:31 am
Forum: Equipment Discussions
Topic: macro scenery with a bridge camera
Replies: 1
Views: 686

macro scenery with a bridge camera

Charles Krebs' old macro scenery posts are amazing, and people keep adding more info as technology advances. See http://www.photomacrography.net/forum/viewtopic.php?t=4864 and http://www.photomacrography.net/forum/viewtopic.php?t=4879&highlight=olympus+angle for example. I started trying to emulate ...
by Lou Jost
Thu Oct 29, 2015 10:51 am
Forum: Equipment Discussions
Topic: Camera for Macroscopy
Replies: 22
Views: 2283

I don't know what the magnification of your lens is, so the following comment may be irrelevant.... If the magnification of that lens is on the low end for the kind of FOVs you would like to have, a mirrorless bridge camera with a small high-density sensor may be able to put more pixels under your s...
by Lou Jost
Mon Oct 26, 2015 10:54 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: 12 shot in this stack taken in hand of a chilled wasp
Replies: 14
Views: 2998

I try to apply the same general guidelines people often use when approving or denying collection permits in ecological reserves. The main principle they (and I) use is that the collection should have negligible impact on the local population. So I would not collect an uncommon, long-lived insect, li...
by Lou Jost
Sun Oct 25, 2015 8:00 pm
Forum: Equipment Discussions
Topic: Help needed for water droplets
Replies: 5
Views: 1049

Use a very fine spray or misting device. The tiny droplets stay on easily, and they slowly grow into bigger ones if you keep adding mist. The trick is to grow the droplets in place rather than try to pour big ones on initially. If the drops have momentum they won't stick.
by Lou Jost
Sun Oct 25, 2015 5:22 pm
Forum: Equipment Discussions
Topic: Optimal sensor pixel density for Mitu 10x
Replies: 23
Views: 5333

Rik, that last paragraph is a good summary. I read the resolution/sharpness article you linked to. Your photo of the aerial image led me to wonder about photographing the aerial image of my Mitu 10x + 200mm tube, using say a 2x or 3x lens on an APS sensor. That's another interesting way to get more ...
by Lou Jost
Sun Oct 25, 2015 2:40 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: What really causes "diffraction blur" ?
Replies: 36
Views: 18615

OK, thanks for the clarification. That helps a lot.
by Lou Jost
Sun Oct 25, 2015 2:24 pm
Forum: Equipment Discussions
Topic: Optimal sensor pixel density for Mitu 10x
Replies: 23
Views: 5333

The difference is especially important when one wants to get lots of pixels under a very small subject. With a bridge camera I can work at 5x or 10x on the sensor, whereas getting the same number of pixels under the same object on an APS sensor requires more like 20x.
by Lou Jost
Sun Oct 25, 2015 5:41 am
Forum: Equipment Discussions
Topic: Optimal sensor pixel density for Mitu 10x
Replies: 23
Views: 5333

Rik, thanks for your comments. Not my intention to make you grouchy, quite the contrary! "The results discussed in the above threads have been subjected to the test of matching reality, and they're held up quite nicely so far. If you think they don't, in some experiment of your own, then the onus wi...
by Lou Jost
Sun Oct 25, 2015 5:23 am
Forum: Equipment Discussions
Topic: Would reversed infinity objectives be telecentric?
Replies: 15
Views: 3275

Rik, thanks for all the detailed advice in these posts about how to do this, and why one would want to do it. The photos above are pretty much the test you suggested just now. They are taken at very small aperture (I think f16) for deep depth of field (no stacking involved at all) and for each test,...
by Lou Jost
Sat Oct 24, 2015 6:31 am
Forum: Equipment Discussions
Topic: Would reversed infinity objectives be telecentric?
Replies: 15
Views: 3275

Thanks for the tip about the term "Optical comparator", which is not one I have heard before. However I'm broke after buying a Mitu and other optics, and after some unforeseen personal expenses. For the foreseeable future I'll have to stick with home-made telecentric lenses. I have seen elf's rig. I...
by Lou Jost
Fri Oct 23, 2015 9:49 pm
Forum: Equipment Discussions
Topic: Would reversed infinity objectives be telecentric?
Replies: 15
Views: 3275

Chris, I've just run through a series of resolution tests with the telecentric combo using butterfly scales as the subject. I can see almost no degradation in the image centers, compared to the normal lens without the Raynox. The corners show some loss of sharpness, and some purple fringing at large...
by Lou Jost
Thu Oct 22, 2015 7:35 pm
Forum: Equipment Discussions
Topic: Would reversed infinity objectives be telecentric?
Replies: 15
Views: 3275

By loss of resolution, I think you mean loss due to the added Raynox? I haven't looked carefully at the effects of adding a Raynox at this long inter-lens distance. Will test tomorrow if I get my real work done in time. But I have tested the Raynox at "normal" separations with this 90mm lens at 0.5x...