Search found 342 matches

by Blame
Sat Jan 31, 2015 8:17 pm
Forum: Equipment Discussions
Topic: How can I harvest and adapt a focus block?
Replies: 22
Views: 6629

The issue about mechanical stability is not so clearcut. What microscopes are designed to do is maintain micron-level stability between the stage and the objective turret . As soon as somebody breaks that particular connection, say by mounting the camera on a copy stand and looking downward onto a ...
by Blame
Sat Jan 31, 2015 5:22 am
Forum: Equipment Discussions
Topic: How can I harvest and adapt a focus block?
Replies: 22
Views: 6629

First because the microscope should also have a perfectly valid xy control for fine positioning the sample. It might need modifying but its solidly held where it is. I only have a couple of examples, but the stage X, Y, or both, controls don't work if the microscope is layed down, because of gravit...
by Blame
Fri Jan 30, 2015 4:28 pm
Forum: Equipment Discussions
Topic: How can I harvest and adapt a focus block?
Replies: 22
Views: 6629

Would you care to expand on your thoughts? --Rik First because the microscope should also have a perfectly valid xy control for fine positioning the sample. It might need modifying but its solidly held where it is. Then the bulk of the structure is fuctional with just the head in the way. Hack off ...
by Blame
Fri Jan 30, 2015 10:33 am
Forum: Equipment Discussions
Topic: How can I harvest and adapt a focus block?
Replies: 22
Views: 6629

How. You sure the question shouldn't be why?
by Blame
Wed Jan 28, 2015 10:10 am
Forum: Equipment Discussions
Topic: Bought an Old Carl Zeiss Jena focus block
Replies: 25
Views: 3350

Maybe you are better off just sticking to keyword "microscope" and waiting for something to turn up local. If it looks good quality in the picture and the seller is willing to check fine focus for distance and stickyness then bid. Normal rules. Wait for a poorly advertised deal. Ask questions early ...
by Blame
Wed Jan 28, 2015 6:15 am
Forum: Equipment Discussions
Topic: Bought an Old Carl Zeiss Jena focus block
Replies: 25
Views: 3350

There is no real assurance that it will be accurate if you gear down the coarse adjust. Well that's all that is happening with a planetary gear system. Makes no difference whether you do it internally or externally. As long as you have some spring tension to take up the backlash (which you would ha...
by Blame
Tue Jan 27, 2015 12:42 pm
Forum: Equipment Discussions
Topic: Bought an Old Carl Zeiss Jena focus block
Replies: 25
Views: 3350

You will have to wait till it arives but my guess is paper weight. You could wast an awful lot of time and end up with something that never really does the job. There is no real assurance that it will be accurate if you gear down the coarse adjust. Better sometimes to fold rather than raise the bet.
by Blame
Wed Jan 21, 2015 9:14 am
Forum: Equipment Discussions
Topic: Apo lens question
Replies: 13
Views: 2947

Blame, I disagree that such a blanket statement can be made about sensor size. As an example, my crop-frame Nikon D7100 has much less noise at base ISO than my full-frame Nikon D700. I also take issue with the idea that this should matter much to most photomacrographers. A much higher priority for ...
by Blame
Tue Jan 20, 2015 6:17 am
Forum: Equipment Discussions
Topic: Apo lens question
Replies: 13
Views: 2947

A FF Camera has an inherently larger dynamic range at optimum ISO. Given that stacking stacks noise they are worth the bother. You don't have to drop much under 5x before reversed enlarger lenses and such come into there own so no bad decision. You could still try for a tube lens. Reversed enlarger ...
by Blame
Mon Jan 19, 2015 6:48 pm
Forum: Equipment Discussions
Topic: Apo lens question
Replies: 13
Views: 2947

It was the infinite I was referring to - though there may be an even newer one than mine. It also may pass some light to the corners of full frame, but I'm pretty sure it's not sharp though I haven't done a lot with it. Memory tells me it's a smaller usable image circle than the Mitutoyo. Bout what...
by Blame
Mon Jan 19, 2015 3:33 pm
Forum: Equipment Discussions
Topic: Apo lens question
Replies: 13
Views: 2947

The Mitutoyo WILL cover short. As short as 3.5x with a 135mm enlarger lens on a FF camera. Catch is that the quality resolution area is much smaller than coverage. 200mm and 5x is a better compromise between corner and center resolution so ChrisR is pointing you in the right direction. The raynox ma...
by Blame
Mon Jan 19, 2015 9:04 am
Forum: Equipment Discussions
Topic: Advice on the suitability of these lenses and bellows
Replies: 16
Views: 4567

Can you guys suggest good legacy lenses which I could get for a good price that I could get a cheap adapter for and use on manual? Most primes 135mm or longer won't vignette too badly when used on an aps-c camera such as yours. That is when used as the tube lens with another mounted in front. My fa...
by Blame
Sun Jan 11, 2015 10:23 am
Forum: Equipment Discussions
Topic: dealing with legacy lenses, diaphragms and a mounts
Replies: 2
Views: 596

1) Better than using one on a full frame camera where they often vignette when perverted to macro. 2. Manual camera and enlarger lenses almost always have a diaphram. Microscope lenses are usually best used without. 3. In the rare case where a diaphragm would help you can start by using a circle of ...
by Blame
Sun Jan 11, 2015 10:11 am
Forum: Equipment Discussions
Topic: Advice on the suitability of these lenses and bellows
Replies: 16
Views: 4567

Don't bother with zooms unless you already have one or can justify buying for non-macro reasons. They rarely work well. That 50mm componon-s should deliver decently reversed on your bellows. You might also concider reversing it and mounting on a prime. There are plenty of cheap 135mm lenses with M42...
by Blame
Sun Jan 11, 2015 5:13 am
Forum: Equipment Discussions
Topic: gigamacro
Replies: 28
Views: 4863

Have you tried calculating the total number of exposures? Stitching means you get to use a bigger bug but that means more depth thus larger stacks. A camera's shutter could wear out fast. In general stack size is going to be proportional to magnification assuming the best of objectives up to about 1...