Tech decisions for a newb

A forum to ask questions, post setups, and generally discuss anything having to do with photomacrography and photomicroscopy.

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Charles Krebs
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Post by Charles Krebs »

Alex,
Of course, you're all a bunch of nutters, and there's no WAY I'm going to be sucked in to going down the same path as all of you… Rolling Eyes
no no, I mean it, really!
The field of microscopy seems to be much more complicated than photography and its measly handful of parameters…
If, just by chance, I happened to mention to them that I was looking around for some objectives (in the <8x range) that might be lying around in a bottom drawer
hmmm.... what's that distant sucking sound I hear! :smt044

Actually microscope objectives become a real viable (and desirable) option from about 10X and up. There are a few nice 4X and 5X that can be used, but the advantage, if any, over the optics we've discussed is not that great (and there are a couple of possible "downsides" like a fixed aperture, shorter working distances, and questions of coverage on a full frame camera).

Microscope stuff does get a little more complicated. There's much to be found in the forum threads. Be best to spend some time searching through them. But briefly (in terms of putting it on your PB-6)...

Newer Zeiss objectives (infinity design) would require an additional tube lens. Not completely impractical, but almost.

Older Zeiss and most other manufacturers (160mmm, finite type) required corrective eyepieces to complete correction for chromatic aberration. Not practical on bellows.

The best options in used gear (without tackling the tube lens issue) are some Nikon "CF" style objectives. Nothing here bwtween 5X and 10X.

For 10X you would be most interested in:
10/0.30 Nikon CF Plan Achromat
Any of the Nikon CF M Plans (finite 210mm tube length). There were several versions made.

Working distance becomes a critical issue. You'll get about 9-10mm of working space with most of the ones mentioned. Many 10X objectives will have unusably short working distances.

No CF Plan Achromats on eBay now, But here are a few CF M Plans: 200280675991, 110280668140, 350079982121 (20mm working distance... other than that image quality about same)

The BD versions have the same "glass" but shorter working distance unless you remove the darkfield component to the mount. (350104224200)

Lastly, microscope objectives were designed to produce a smaller image than the other optics we've discussed. No problem with the D300, but with the D700 you may want to check the corners to see if it's up to your needs.

augusthouse
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Location: New South Wales Australia

Post by augusthouse »

* post overlap with Charlie

Alex,

In regard to milling/drilling tables. There are some options available in Australia; I've not used them myself, so would be best to ask Rik about the 'fine details'.

Here is one such item:
eBay # 260351287441 (put that number in the eBay search box)

This type of approach will cover the X and Y ( I've even seen Rik use a similar approach on the Z axis on occasion).

The Proxxon (what is a Proxxon you may ask - details to follow) is also available in Australia - I will need to recall the model numbers and find a link - from memory they were just under AUD $300.

*http://www.proxxon.com.au/ (type 27100 in their search box - should arrive at PROXXON 27100 KT 70 COMPOUND TABLE AUD$275.00).

........................................

Vertical or horizontal (and anywhere in between) are all achievable and applicable. It is good to have options on-hand.

Have you read the forum threads regarding the use of microscope objectives on bellows? Very interesting reading. Basic survival knowledge - use finite objectives that correct for CA within the objective rather than those that rely on assistance from the eyepieces, etc.

Discussions surrounding microscope focusing blocks also contain significant info to assist in arriving at a decision.

I have another PDF of Kaiser gear. It has more info and pics than the one attached to the link I posted earlier. It's 1.97mb in size and I am trying to locate where I downloaded it from - no success as yet.

Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

ayashko
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Location: Melbourne, Australia

Post by ayashko »

so something like these (the 10x specifically) wouldn't be of much use?

ebay: 310117458095

cheers

Alex


ps. I'm going to nab the movement he's also got, so keep your greedy paws away… 8)

Charles Krebs
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Post by Charles Krebs »

Alex,

No not really useful. The only one that has a chance on a bellows might be the M 10X (and you would be paying too much for it alone). The other three would be paperweights without a proper microscope (working distance a small fraction of a mm with the 40X, and oil immersion needed with the 100's). It's an older version, so it would likely show a fair amount of CA used on a bellows... (Unfortunately one can only guess with stuff that's not been "tried" out in this way before).

BTW, if the "movement" you're thinking of is 310117628819, that's not really suitable to move things for stacking.

ayashko
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Location: Melbourne, Australia

Post by ayashko »

'twas the movement, but I was thinking of coarse positioning at this stage–I'm still looking for focus stage/movements.

Thanks for the information.

Alex

ayashko
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Location: Melbourne, Australia

Post by ayashko »

Charles, from searching through the site, I've come across some veery nice pics of yours using the companon 28/4. So I went and borrowed the one I saw the other day. Could you confirm for me if you get a chance, is it the same as this one?
I've got a 28 f4 as in the image - not the 28 f2.8 which is listed.
If it is, could you tell me what the front end thread is so I can track down some adapters please? From what I've been able to gather, it's a 43 x 0.75?

Cheers

Alex

Charles Krebs
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Post by Charles Krebs »

Alex,

You'll need to measure it. It's the same lens I have but it is in a different mount than mine (the old mount had a 30.5mm filter size, but this appears obviously larger).

Eric F
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Location: Sacramento, Calif.

Tech decisions for a newb

Post by Eric F »

Charles, I have been following your discussion with Alex with great interest (as with all of your discussions!). You mentioned that no Nikon CF Plan Achros were presently available on eBay -- but there was one: a Plan 10/0.30 DL, the phase version of the CF N 10x/.30, which has the same specifications as that lens. I wanted to buy this lens, so selfishly did not divulge the knowledge that it was available (I lost the bid anyway...). Now my naive question: would a phase and non-phase version of what must be essentially the same lens perform equally well in a non-phase role? That is, would the DL phase version of the CF N 10/.30 have been a good substitute for the non-phase lens if I was only interested in non-phase photography? I have several other phase objectives (Leitz 160's) that seem to give good results for non-phase functions, but I don't have their non-phase equivalents for comparative study. I haven't seen this issue discussed before on the forums, and so wonder what you might have observed.

Thanks for any info,

Eric

Charles Krebs
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Post by Charles Krebs »

Eric,

Not a naive question at all!

It's actually a reoccurring question in microscopy groups. (Whether phase objectives will give an image equal to a "brightfield" objective when used in non-phase illumination). The last time I remember this getting a big discussion on the Yahoo group I seem to remember some strong opinions that there is no problem doing this, and that the biggest downside might be a reduction in contrast. And yet I have one book on microscopy that specifically warns against it, saying the images will be inferior. I suspect that the wide variety of opinion is because there is a great deal of variability between the performance of different phase objectives when used for other lighting methods. This is the sort of non-answer I hate to both get and give, but it does seem in this case the best answer is "try it".

And now, when it is posed in regards to using these objectives on a bellows, I simply don't know. If I had my choice I would choose the non-phase, simply because my gut says the phase ring can't make things better, but could be a potential problem.

I haven't use phase contrast in some time, but I actually do have the Nikon 10/0.30 CF N phase. If I get a chance I'll try to to an A:B comparison and see what results.

Harold Gough
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Post by Harold Gough »

In my experience, at least for thickish specimens such as mites and springtails, a x10 phase contrast objective would give an acceptable performance with bright field but higher magnifications required separate bright field and phase lenses for working to the limits of resolution of fine detail. That was with a green filter in use for phase objectives, possibly the important factor.

Harold
My images are a medium for sharing some of my experiences: they are not me.

Eric F
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Tech decisions for a newb

Post by Eric F »

Thanks Charles; you've given me a complete and very informative answer. Anyway, the older I get, the more I learn how few complexities can be answered in simple yes or no/ black or white terms....

I haven't tried to work with any objectives on 'real' bellows yet. Rather, I am using the equivalent of metal bellows; it is a wonderful, 50 year-old Leitz monocular scope I was lucky to find on eBay. It is like the common type of 'Doctors scope' you often see for sale, except it was originally fitted with an "Opak vertical illuminator" (non functional) instead of a revolving nosepiece. The monocular tube is a straight, vertical draw-tube -- with tube length indicated along the side. You simply screw an objective into the bottom, then adjust the tube length appropriately. Though the original stage on the scope was very nice, I have removed it and am instead using a stand attached to a Newport XYZ Linear Stage, which gives me more room (the tube is also adjustable, of course). My subjects are pinned insects, and I am using a "KD-200" LED ring light modified into a dome light [see: http://www.cdfa.ca.gov/phpps/ppd/entomology/dome.html] for illumination at present. However, this light -- while very nice for stereo microscopy -- is probably insufficient for this compound microscope setup, so I am working on attaching a macro twin lite flash to the unit. For now, my camera (a Canon EOS 40D) sits attached directly to the photo eyepiece (using a SRB-Griturn slr adapter). With mirror lock-up and a remote switch, this setup seems very stable for photography (movement required for stacking occurs on the separate XYZ stage). Eventually, I will try to mount the camera on a separate photo stand -- to see if that offers any benefit.

Actually, it was your magnificent 'fly head' (of Nikon & Helicon fame) that inspired me to pursue this type of photography. I'm afraid my results are too modest to share at present, but I am hopeful of eventual improvement. I'm really very grateful for this forum and the many wonderful contributions that the well-informed and photographically talented members present.

Harold, the objective lenses I need for insect photos are mainly 4 to 10x, long working distance ones (however, trying to find these with high na + long wd is proving difficult & expensive!). So, maybe any interference caused by phase rings is much more apparent at higher magnifications than these.

Thanks again, Eric

Charles Krebs
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Post by Charles Krebs »

Eric,
Eventually, I will try to mount the camera on a separate photo stand -- to see if that offers any benefit.
Rather than going through the effort to see if it helps, it's not hard to "test" you setup to see if there would be a benefit. Compare several exposures of very fine detail using your "normal" exposure method with the same shots taken using an "open shutter" technique....

- Very low ambient light (darkened room)
- Illumination turned off
- Camera shutter opened
- Several second pause (all vibrations dampen out... don't lean on table! :wink:)
- Subject exposure lights switched on/off (or flash fired manually)
- Shutter closed

If these tests show a noticeable improvement, then a separation of the camera to a separate stand could be one way of improving things. (If you are using electronic flash there are other, simpler methods).

Eric F
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Tech decisions for a newb

Post by Eric F »

Thanks Charles -- more good advice. I will give this test a try.

Eric

augusthouse
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Location: New South Wales Australia

Post by augusthouse »

I mentioned a Kaiser PDF earlier in the thread.

Here it is:

http://www.meyerinst.com/html/stands/stands.pdf

hmmm...think I would need more than one shopping trolley...

Craig
To use a classic quote from 'Antz' - "I almost know exactly what I'm doing!"

ayashko
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Joined: Mon Jan 26, 2009 11:08 pm
Location: Melbourne, Australia

Post by ayashko »

thanks Craig, I'm slowly accumulating all the bits and pieces I'll need to get this happening, and will post either pics or questions as soon as I can… :)

cheers

Alex

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