Search found 4524 matches

by Lou Jost
Wed Nov 18, 2015 8:17 pm
Forum: Beginners Macro
Topic: butterfly squame
Replies: 4
Views: 1800

Stunning. What are you using?
by Lou Jost
Wed Nov 18, 2015 8:02 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Rear-standard focusing with infinity objectives?
Replies: 19
Views: 4517

Rik, so the 10x at objective/tube lens separation = the sum of the focal lengths is going to be constant regardless of distance from front of lens to subject? In other words, it does not depend on your choice of 21mm? I ask because the Mitu has a working distance of 34-35mm. That's interesting thoug...
by Lou Jost
Wed Nov 18, 2015 5:23 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Rear-standard focusing with infinity objectives?
Replies: 19
Views: 4517

Rik, yes, this helps, thanks. I was talking about moving the back of the camera. I see I made a mistake in my calculations. And in this case, your math shows my intuition is mistaken.
by Lou Jost
Wed Nov 18, 2015 2:03 pm
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 205
Views: 98900

Wow! Thanks for that link, Rik. Looks like he is trying to induce nuclear fusion. Maybe he is making those fancy minerals right there out of hydrogen and oxygen.
by Lou Jost
Wed Nov 18, 2015 2:00 pm
Forum: Equipment Discussions
Topic: Rubber smell driving me crazy
Replies: 12
Views: 1626

I tried bags before writing my post--didn't work. My tires are baking in the sun outside right now, and will probably stay there a very long time.

Some sites recommend white vinegar, and I will probably try that eventually. My dinner table still smells like rubber even with the tires gone. Yuck.
by Lou Jost
Wed Nov 18, 2015 1:54 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Rear-standard focusing with infinity objectives?
Replies: 19
Views: 4517

Rik, thanks for your quantitative analysis. But the figure you give for the change in magnification as you move from 20 to 21 mm seems much too large. Are you sure about it? For the Mitu, the working distance is 35mm (but this doesn't matter). So let's say we make a 1mm thick stack by moving the cam...
by Lou Jost
Wed Nov 18, 2015 11:54 am
Forum: Equipment Discussions
Topic: Rubber smell driving me crazy
Replies: 12
Views: 1626

Rubber smell driving me crazy

Admittedly not an optical question...I built a vibration-resistant support using small rubber inner tubes as a base, with a slab of granite on top. But the rubber smell drives me crazy. Anybody know how to get rid of it?
by Lou Jost
Wed Nov 18, 2015 10:34 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 205
Views: 98900

Thanks. That's a lot of lamps!
by Lou Jost
Wed Nov 18, 2015 9:35 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 205
Views: 98900

Can you tell us more about how you lit your most recent set of images? I really like them, and it can't be easy to illuminate some of these, especially ones with all those glossy mirror-like crystal surfaces.
by Lou Jost
Wed Nov 18, 2015 6:32 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Preventing leaf curl for macro photography
Replies: 14
Views: 1603

Would the leaves still roll up if they were transported in a closed vertical tube with distilled water in the bottom, and if you kept their bases in water during the photography?
by Lou Jost
Wed Nov 18, 2015 5:35 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Rear-standard focusing with infinity objectives?
Replies: 19
Views: 4517

....and to what advantage? As Rik has often written, the advantage is a stationary entrance pupil so no changes in perspective occur during stacking. Maybe the Mitu is "close to telecentric" but it is not telecentric. And many other lenses are not even close to telecentric. Why not generally do it ...
by Lou Jost
Tue Nov 17, 2015 8:23 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Rear-standard focusing with infinity objectives?
Replies: 19
Views: 4517

Rear-standard focusing with infinity objectives?

Rik has often written about the advantages of keeping the lens fixed when focus-stacking, yet most people here (I think this includes Rik) seem to move the whole camera plus microscope objective. Yet it would be fairly easy (especially when the tube lens is a Raynox on bellows or extension tubes) to...
by Lou Jost
Tue Nov 17, 2015 3:48 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Does Stackshot buzzing noise cause vibrations?
Replies: 8
Views: 2811

dlg, those factors can be eliminated fairly easily. It is quite another matter if the main device holding the camera causes inherent vibration. Like a Trojan horse, it sits there in the heart of the set-up, invited by us innocents. We spend our time building vibration-proof supports, shutting off re...
by Lou Jost
Tue Nov 17, 2015 11:55 am
Forum: Technical and Studio Photography -- Macro and Close-up
Topic: Photo of Ploum
Replies: 205
Views: 98900

Your lighting is exceptionally beautiful!
by Lou Jost
Mon Nov 16, 2015 7:47 pm
Forum: Nature Photography -- Macro and Close-up
Topic: Madagascar part XVI
Replies: 4
Views: 1318

Thanks for the link, I look forward to reading your posts there.