Search found 1311 matches

by enricosavazzi
Fri May 14, 2010 4:23 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Case study: "Portable" stacking set-up.
Replies: 44
Views: 28560

Enrico... it sounds like you may have this type of rotating back. When the bellows material is removed you can see that the rear bayonet mount is inserted through the back standard and "attached" via a screw-on metal locking ring. This ring has several "spring" fingers that provide the tension for ...
by enricosavazzi
Thu May 13, 2010 8:11 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: 25mm vs 12.5mm vs 8mm for 10x magnification
Replies: 18
Views: 4890

Re: 25mm vs 12.5mm vs 8mm for 10x magnification

Hi all The 8mm lens at f/2.8 is darker at 10x compared to the 12.5mm at 10x and the 12.5/2.8 was darker at 10x compared to the 25/2.8. I am not really sure if this should be the case, I thought it should be the other way around because with longer lenses you need longer bellows thus more light lost...
by enricosavazzi
Thu May 13, 2010 7:06 am
Forum: Equipment Discussions
Topic: JML 21mm f/3.5 Lens---Mounting Techniques
Replies: 69
Views: 63141

My solution was epoxying the rear part of the barrel of an RMS microscope objective inside the barrel of the JML lens. You can see a detail in the top right portion of the picture, and the modified JML lens among colleagues. One thing to remember in this type of modification is that the two parts sh...
by enricosavazzi
Thu May 13, 2010 3:34 am
Forum: Equipment Discussions
Topic: JML 21mm f/3.5 manufacturers' specs
Replies: 15
Views: 9678

BTW, I notice that morfa's lens has a long axial scratch extending from the "L" of JML to the end of the lens barrel. Mine does too. Do other people's? --Rik Mine does have the scratch. I have seen internal lens barrels with comparable scratches, as well as optical elements with comparable pencil m...
by enricosavazzi
Thu May 13, 2010 3:09 am
Forum: Equipment Discussions
Topic: Leitz/Leica/other microscope stand for photomacrography?
Replies: 11
Views: 13743

Olympus CH stand

One more update - I got a complete Olympus CH microscope at about half the price I paid for the Leica Galen stand I discussed above, and could not resist the offer. Here are my impressions. Like the Leica Galen, this is not a stand I would recommend for microscopy. The illuminator and condenser are ...
by enricosavazzi
Wed May 05, 2010 7:50 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Case study: "Portable" stacking set-up.
Replies: 44
Views: 28560

Charlie, Enrico, Did your solid version come with M42 mounts or was it fitted with the Exakta bayonet mounts? I ask since the black solid one I have has such bayonet mounts and I wonder, if they could be changed against M42 mounts salvaged from one of my lightweight versions, especially as Enrico w...
by enricosavazzi
Tue May 04, 2010 6:52 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Case study: "Portable" stacking set-up.
Replies: 44
Views: 28560

I would actually use an old Exacta bellows (see picture). This is similar to this Pentax in many ways... even uses the same rail… but it is much heavier and locks down more solidly than any bellows I have ever seen. The Pentax shown above is cast metal, but “hollowed” (don’t know the correct term)....
by enricosavazzi
Mon Apr 26, 2010 12:25 pm
Forum: Macro and Micro Technique and Technical Discussions
Topic: Case study: "Portable" stacking set-up.
Replies: 44
Views: 28560

Enrico and Chris, The trinoc head I'll be using has a three position slider... 100% viewing. 20/80 viewing/trinoc, and 100% trinoc. There is a thick piece of multi-coated flat glass in the 100% trinoc position. My guess is that this is there to keep it par-focal to the other positions that must use...
by enricosavazzi
Mon Apr 26, 2010 9:07 am
Forum: Equipment Discussions
Topic: Lenses for reversing?
Replies: 20
Views: 5436

Nikon open [actually closed, as already corrected above] (or as aperture ring is set) ... Actually, this is true only of Nikon lenses with an aperture ring. Lenses without this (e.g. Nikkor G lenses) keep the aperture fully closed, and are essentially impossible to use reversed (unless one uses a s...
by enricosavazzi
Mon Apr 26, 2010 12:30 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Case study: "Portable" stacking set-up.
Replies: 44
Views: 28560

... what I really want to do is incorporate an old trinocular head I bought just for this purpose. I want to modify the head so that I can get a clean shot (ie. no glass at all) in one of the slider positions. ... I did this a couple of weeks ago, with a Nikon Labophot head (which, incidentally, do...
by enricosavazzi
Sun Apr 25, 2010 1:35 pm
Forum: Equipment Discussions
Topic: Navitar 6000 6.5:1 zoom macro lens w/ Nikon 10x/0.30 inf obj
Replies: 10
Views: 3031

I have some of these zoom lenses, but never tested them properly. Vignetting in the corners on an APS-C sensor is indeed a problem, as far as I recall: http://www.savazzi.net/photography/photomacrolenses4.htm Some people did try to build the Optem 6000 into a high magnification microscope, but not w...
by enricosavazzi
Sun Apr 25, 2010 4:26 am
Forum: Macro and Micro Technique and Technical Discussions
Topic: Case study: "Portable" stacking set-up.
Replies: 44
Views: 28560

Charles, [warning: some semi-serious text follows] this is a nice equipment, but, as you have found, portability and stability are not easy to obtain together. Some time ago I sat down to think about solutions along similar lines. Mass absorbs vibration, so my first thought was incorporating the pho...
by enricosavazzi
Fri Apr 16, 2010 1:31 pm
Forum: Equipment Discussions
Topic: Making a big telecentric lens (a though experiment)
Replies: 6
Views: 2901

See HERE , "Brightfield Illumination of Large Field Sizes" by Theodore M. Clarke. Fig 17 illustrates the basic scheme. Clarke uses the method to make both the illumination and the imaging telecentric at the same time, in order to photograph mirrored surfaces. The same technique, applied to imaging ...
by enricosavazzi
Fri Apr 16, 2010 9:34 am
Forum: Equipment Discussions
Topic: Questions about Flashlight
Replies: 3
Views: 1209

Re: Questions about Flashlight

Hey guys, Unfortunately I recognized, that my 580EX2 Speedlight is too heavy for using it outside in nature. I tried some gooseneck variants but no gooseneck is strong enough to hold it the way I want or even hold it the way the gooseneck should. Best regards, Magom I did not have much success with...
by enricosavazzi
Fri Apr 16, 2010 9:23 am
Forum: Equipment Discussions
Topic: Making a big telecentric lens (a though experiment)
Replies: 6
Views: 2901

I assume you've googled and found the Schneider pages. The Bilateral construction is intriguing. Perhaps you could make one with two 300mm f2.8s back to back, and a camera moving laterally, behind, though I'm not sure I understand how it works. Maybe say a 200mm behind the 300? There's a bit here, ...