Search found 128 matches

by Joseph S. Wisniewski
Sun May 24, 2009 10:28 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Bee vision -- filtering and mapping for UV photography
Replies: 14
Views: 3606

Re: Bee vision -- filtering and mapping for UV photography

Bees have in contrary to us humans a special receptor in their eye which has a UV sensitivity which peaks around 360nm (UV-A). They also have a blue and green sensitive receptor - quite similar to what we have. If it is true that bees have S (blue) and M (green) receptors similar to human, then I t...
by Joseph S. Wisniewski
Tue Mar 10, 2009 5:53 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Securing butterfly wings for Photomacrography
Replies: 15
Views: 4318

I have a real strange sense of deja vu here... For higher magnifications and fast lenses, a piece of glass as thick as a standard photographic filter (2mm thick glass) will play hob with your resolution. I knew I wasn't going crazy. Yesterday's post about resolution targets, and the use of a window...
by Joseph S. Wisniewski
Tue Mar 10, 2009 5:50 pm
Forum: Equipment Discussions
Topic: available Test chart for resolution sharpness
Replies: 21
Views: 5595

That aside, I was going to propose the use of "popped top" microprocessor chips. Their dies are huge, they're wonderfully flat, and they have features down to insanely small levels. Homomorphic deconvolution can compute resolution from the patterns of a chip. How do you 'pop a top' ? For ceramic pa...
by Joseph S. Wisniewski
Tue Mar 10, 2009 5:45 pm
Forum: Equipment Discussions
Topic: available Test chart for resolution sharpness
Replies: 21
Views: 5595

There is a trick for cheaply producing high resolution virtual targets using a microscope objective as a tiny projection lens. Basically you set up the microscope optics "in reverse" to turn a large resolution target into a tiny image of a resolution target, which you look at using the lens being t...
by Joseph S. Wisniewski
Tue Mar 10, 2009 5:40 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Good book for collecting/preserving insects
Replies: 7
Views: 2044

When I was very young (maybe 4 or 5) I discovered that pretty much any reasonably thick book could be used to collect and preserve insects... There are probably still books in my parents home that have "preserved" insects between the pages. As a bonus, insects collected in this way are especially fl...
by Joseph S. Wisniewski
Tue Mar 10, 2009 5:36 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Securing butterfly wings for Photomacrography
Replies: 15
Views: 4318

I have a real strange sense of deja vu here... For higher magnifications and fast lenses, a piece of glass as thick as a standard photographic filter (2mm thick glass) will play hob with your resolution. A lot of us here play with microscope objectives. Those are typically marked as to whether they'...
by Joseph S. Wisniewski
Tue Mar 10, 2009 5:30 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: 50mm El_Nikkor vs 40mm Apo-Componon
Replies: 23
Views: 24856

My camera (D2Xs) will not fit onto the Nikon PB-6 bellows, the base of the camera is too deep. I have to mount an extension tube, a PN11 (52.5mm), between the bellows and the camera. I also have a complex lens mount at the other end of the bellows. Thus with the PN11 + bellows at full extension + l...
by Joseph S. Wisniewski
Mon Mar 09, 2009 6:04 pm
Forum: Equipment Discussions
Topic: available Test chart for resolution sharpness
Replies: 21
Views: 5595

How about EPROM memory with a window for ultraviolet erasure. For incident light illumination tests. The transparent window will throw all the tests off. Fast lenses look at a pretty wide cone of light, and the shallower the angle, the longer a distance through the window light has to travel and th...
by Joseph S. Wisniewski
Tue Feb 03, 2009 8:58 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Are X-Rays macros?
Replies: 15
Views: 4802

Right now, I'd be more concerned with getting my own body through airport security, with my wrist full of metal pins. Dr. appointment went well today, new, more comfortable cast. Pins come out in two more weeks. I got dizzy and had to lie down when they cut off the old cast and I saw those pins stic...
by Joseph S. Wisniewski
Tue Feb 03, 2009 8:40 pm
Forum: Equipment Discussions
Topic: A DIY Reversed Lens Linkage
Replies: 4
Views: 2063

Much easier to get a coupling ring and reverse attach an old manual lens onto a longer lens. Are you doing this on a Quanon? If so, how do you control aperture on the reversed lens? If you're leaving the reversed lens wide open and controlling aperture on the "longer lens" mounted on the camera, yo...
by Joseph S. Wisniewski
Thu Jan 22, 2009 2:02 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Are X-Rays macros?
Replies: 15
Views: 4802

Are X-Rays macros?

Day 9 of the broken wrist saga, can't shoot, can barely type, can't play a flute, sleep at least 12 hours a day... So, what have I got? Lots and of time, and drugs... Which brings up the obvious thought: since X-Rays are essentially shadows, shot by consummated "light", they are always at 1:1. Does ...
by Joseph S. Wisniewski
Wed Jan 07, 2009 12:14 pm
Forum: Equipment Discussions
Topic: Macro Nikkor 65/4.5 vs. Zeiss Luminar 63/4.5
Replies: 3
Views: 3654

Interesting review. Thanks for posting it... One silly question. Did you reverse the 60mm micro-Nikkor and set the lens's magnification ratio to something approximating your reproduction ratio? For 3x, set it to 1:3 when reversed. Or course, due to the moving front node when you do this, actually fi...
by Joseph S. Wisniewski
Tue Dec 30, 2008 4:21 pm
Forum: Equipment Discussions
Topic: Macro to infinity spherical|orthogonic|lenticular pano head
Replies: 19
Views: 27303

Re: Macro to infinity spherical|orthogonic|lenticular pano h

For focus stacking you'd still need to rescale in the cross-scan direction to avoid echos. Unfortunately. The way around that is a volumetric stacking and panning algorithm, but right now we're a good distance away from seeing those. I've played with small ones, but building a 3D "volume" of pixels...
by Joseph S. Wisniewski
Tue Dec 30, 2008 12:25 pm
Forum: Equipment Discussions
Topic: Macro to infinity spherical|orthogonic|lenticular pano head
Replies: 19
Views: 27303

Re: Macro to infinity spherical|orthogonic|lenticular pano h

That will be interesting. The rear focusing motion is a little ugly, the object side focal plane displacement is not linear with the image side movement of the standard. I'm not sure I understand. Can you elaborate? I can always elaborate. Verbosity is one of my few character flaws... OK, say we're...
by Joseph S. Wisniewski
Tue Dec 30, 2008 11:59 am
Forum: Equipment Discussions
Topic: Macro to infinity spherical|orthogonic|lenticular pano head
Replies: 19
Views: 27303

Re: Macro to infinity spherical|orthogonic|lenticular pano h

Aluminum can be worked with standard woodworking tools, so just think of it as shiny wood and you'll be able to do anything :lol: The 8020 aluminum extrusions are actually pretty easy to work with. http://www.8020.net/ has lots of examples and they also have an ebay store. Yes, I frequently abuse m...