Search found 40 matches
- Mon May 09, 2016 11:48 am
- Forum: Equipment Discussions
- Topic: Macro photography with wide angle lenses
- Replies: 19
- Views: 2265
Nothing nice This isn't nice : http://www.4photos.de/camera-diy/Shortest-Canon-EF-Extension-Tube.html I love them :-) I have one of my short tubes always with me when I go to a photo tour. They are not only useful for wideangel, but also for 50mm focal length I use those often. My short extension t...
- Mon Mar 30, 2015 1:06 pm
- Forum: Equipment Discussions
- Topic: Fungus in my old Schneider Companon f5.6 80mm lens
- Replies: 11
- Views: 2376
Re: Polishing lenses - my glasses this time !
... Perhaps you can recommend some polishes that I can use on my reading glasses that live around my neck - they are getting badly scratched to the point where I try to clean them constantly - no luck. ... I got my Nirgin car glas polishing agent from a car repair shop. That is intended for glass a...
- Sun Mar 29, 2015 11:32 pm
- Forum: Equipment Discussions
- Topic: Fungus in my old Schneider Companon f5.6 80mm lens
- Replies: 11
- Views: 2376
... Yes it is possible in principle, but not recommended for two reasons - first is that the polishing will probably change the optical properties of the lens, and second - a proper polish without changing the optical properties is likely to be very, very expensive... As an optical engineer I thoug...
- Mon Mar 23, 2015 1:19 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Lomography Petzval lens
- Replies: 16
- Views: 14128
Those soft focus lenses like the Imagon or that Fuji use those special multi hole apertures to get different amounts of good corrected image and spherical aberration. The center has good correction, and the borders have a lot of spherical aberration. Many holes gives a softer image, less holes at th...
- Sun Mar 01, 2015 12:47 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Lomography Petzval lens
- Replies: 16
- Views: 14128
Re: Lomography Petzval lens
... For a long time, I'd thought about buying an antique Petzval and modifying it for a modern camera. This is certainly possible, but has its difficulties: Lots of antique lenses have serious condition issues, such as lens separation or fungus, and optically good specimens tend to be expensive. Al...
- Sun Mar 01, 2015 12:41 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Path to shutterless camera? Konost/CMOSIS development
- Replies: 9
- Views: 4389
... Shutterless cameras do exist as dedicated instruments for microscopes and telescopes. But they tend to be expensive, use older-technology Kodak sensors or too-small sensors, and be locked by restrictive software that may cost more than the hardware, is not open source, and may not be updated in...
- Tue Sep 09, 2014 7:15 am
- Forum: Equipment Discussions
- Topic: Tokina 90mm macro ATX f2.5 "Bokina" aperture lever
- Replies: 2
- Views: 2910
I have the Vivitar 90 Series 1 - the predecessor of the Tokina 90. For this I found a parts list - this could probably hep a bit: http://www.boggys.co.uk/page23.html Here a German user has tried this repair: http://www.dslr-forum.de/showthread.php?t=976752 But images are lost in thes forum. First he...
- Tue Oct 08, 2013 6:58 am
- Forum: Equipment Discussions
- Topic: Coated clear-glass-filter *behind* older optics for digital?
- Replies: 2
- Views: 1235
Old thread but I want to add: Digital optimized lenses are calculated with the AA + IR-Cut filter glass in mind. Old lenses are designed to have no glass between last lens and film. From this it is better to reduce parallel glass behind the old lens system (like the filters in fisheye lenses) to opt...
- Tue Oct 08, 2013 6:21 am
- Forum: Equipment Discussions
- Topic: Minolta lens(es) on Canon body?
- Replies: 4
- Views: 1754
I made a Sony A to Canon EF mount adapter . But as Charles wrote, it is with most lenses not really good to use - the lens has no iris ring, and the tickness one could use for an lever is too small - as long as one wants infinity. It seems possible to make an macro adapter with iris lever (like the ...
- Wed Mar 06, 2013 5:27 am
- Forum: Equipment Discussions
- Topic: Storage and cleaning of microscope objectives?
- Replies: 8
- Views: 1890
For dry clenaing I use sometimes a fresh broken styrofoam (Styropor) surface. For wet cleaning I reccomend to take a very, very small amount of the liquid. I think it is not sure that the lens border it thight enought to withstand much liquid on the lens. On normal photographic lenses I had once/twi...
- Wed Mar 06, 2013 5:17 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Telecentric combo at 0.8X to 1.69X
- Replies: 69
- Views: 45719
- Tue Mar 05, 2013 7:55 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Telecentric combo at 0.8X to 1.69X
- Replies: 69
- Views: 45719
Wouldn't it be possible to take an old manual lens and remove the actual lenses from it to get a tube with a diaphragm inside it? That diaphragm would still be operated by the camera. You just need to figure out a way to attach the actual lens to this and to keep the proper distance. Possibly use a...
- Mon Feb 11, 2013 2:10 am
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: CCD or DSLR?
- Replies: 9
- Views: 3434
Most consumer cameras have moving parts, most uncooled machine vision cameras not. No movement results in probably sharper images. And moving parts could damage more easily. Better DSLR cameras work for probably 300.000 images. I work at a machine vision camera manufacturers R&D department, and ther...
- Tue Jan 22, 2013 4:12 am
- Forum: Equipment Discussions
- Topic: DIY Tilt macro lens
- Replies: 6
- Views: 2876
- Mon Jan 21, 2013 1:08 pm
- Forum: Macro and Micro Technique and Technical Discussions
- Topic: Telecentric combo at 0.8X to 1.69X
- Replies: 69
- Views: 45719
With such a commercial tube with iris inside it is probably a problem when the iris is not in the register distance - no telecentric perspective. To get the lens automatism one could use normal expensive extension tubes and build a (probably removable) iris inside. Such will get lens a bit more auto...