Choice of microscope objective for bellows and SLR

rjlittlefield · Post by **rjlittlefield** » Sat Apr 10, 2010 9:07 am

morfa wrote:Rik knows much more about this than I though so I guess it's not safe to make this assumption!

The question of which objectives are CF is one where mostly what I know is that I don't know enough.

I agree that the general appearance of the objective matches the non-LWD CF's that are shown in Nikon's brochure.

What I don't know is whether the objective really is from that same series, or it just has the same general appearance.

Sometimes the situation with objectives reminds me trying to ID insects.

The main reason I'm looking at the new Nikon objective stocked by Edmund is that I'd love to have one objective I could point to as a reasonably good known quantity, without always having to say "but you should ask before buying because there are a lot of objectives that look similar but don't work as well."

--Rik

dmillard · Post by **dmillard** » Sat Apr 10, 2010 10:31 am

morfa wrote: Oh well, then lets hope that Rik's Achromat doesn't turn out to be too good and that the one you bought indeed turns out to be CF. Judging from how very similar it looks to the non-LWD E Plan pictured in the brochure I must say I thought it safe to assume this.

Although it is not illustrated, it is described in the specifications table (page 14), so I would assume that it is also CF (with a caveat that my assumptions are frequently wrong

).

David

rjlittlefield · Post by **rjlittlefield** » Sat Apr 10, 2010 11:17 am

Yeah, probably I'm being too cautious in this case.

But I am mindful of what Charles Krebs wrote for us several years ago (Jan 2007, HERE):

At least "on paper", it would seem that the CF series, 160mm tube length objectives might be the best candidates for use directly on a camera bellows. But it is probably not that simple. I have several CF series objectives. One (which I have no longer) was a 10X LWD (long working distance) that gave color errors I could not live with. I have two other 10X that are OK, so I don't know if it was just that one sample or something more common.

Since then, I think we have collectively and individually learned a lot about what works well and what doesn't. But I'm pretty sure there are still gaps, even though I don't know where they are. I do know that one of the lenses in my collection is a Nikon 4X NA 0.10, labeled "E" and looking just like the E Achromat shown in the Nikon CF brochure. But I never use it because the image quality including CA is worse than what I can get with ordinary macro lenses. Is the objective a bad sample, is it not a CF in the first place, are my expectations wrong? I have no idea.

--Rik

bklein · Post by **bklein** » Sat Apr 10, 2010 6:59 pm

What do you guys think of a 5X like ebay 280477402160

Also a 4X (can't find anything about it) ebay 300414634777

Thanks,

Barry

ChrisR · Post by **ChrisR** » Sat Apr 10, 2010 7:39 pm

Now we aren't paying attention, are we?

The first one you found is an infinity objective. Needs a tube lens you don't have. Not as good as a finite one, for bellows use. I'll post some pics someday
The same vendor has one which is a 210, and looks new enough to be a CF:
280477395649

The other one whose number you gave, which is about to vanish, satin finished barrel, is I think an older, non CF.

I happen to have a pic of a few:

All Nikon apart from the last:
Red = infinite type - avoid
Green = CF, finite, go ahead
Grey, 2x is too low to be very interesting. You may as well use a 50mm macro or a reversed enlarger lens. Surprisingly short WD at a few mm.
Blue is a BD ( which is CF) like an MPlan 210/0. Ok but see the thread is bigger. Unscrews as shown to give longer WD, the nosepiece houses a light pipe for incident light microscopes.
White is all white cos it's cheap - probably a few dollars only. Olympus Finite not CF, but not too bad for the money

Note that the paint comes off some. There are two 4x 0.13s there.

The Apo 2x was about $180, the others half, or less, or much less. Various sources.

bklein · Post by **bklein** » Sat Apr 10, 2010 11:52 pm

ChrisR wrote:Now we aren't paying attention, are we?

#####, someone snuck that "inf" on the description later....

Evil forces are at work.

How about 200451422254. May be 4X, may be 5X....

ChrisR · Post by **ChrisR** » Sun Apr 11, 2010 12:47 am

?? wrong picture?

Looks late so likely to be CF though it's an E - not quite so "plan", maybe, and way too expensive.
I don't think "we" that is to say Charles Krebs, has a copy of all the brochures they produced, so there's a lack of data on the genealogy of the dynasty.
Plenty of scope for confusion too, when they were producing CF160 objectives concurrently with CFI60s.

bklein · Post by **bklein** » Sun Apr 11, 2010 8:37 am

And here is another variation: 280455057972
Like yours but "DIC"..... ?
What impact does "DIC" have for our bellows use?

ChrisR · Post by **ChrisR** » Sun Apr 11, 2010 9:21 am

What impact does "DIC" have for our bellows use?

Nil, for opaque specimens.
Suggest you do some googlin, you'll find far more answers. Links eg from here http://www.microscopyu.com/articles/opt ... ecial.html
will keep you entertained all day

bklein · Post by **bklein** » Sun Apr 11, 2010 2:53 pm

True, I could spend my day Googling to find the answer but actually I first tried searching this forum and kinda gave up when it came back with 1500 hits and nothing definite found in several minutes of looking within them. (try searching with DIC and objective as terms...) I suspect the information I find outside of the forum would say as your reference did - that it works normally in BD scopes. That to me is not really an answer. I am looking for first hand experience with such objectives on bellows by more experienced guys like you and Charles...
(I've actually spent the last two days trying to get rid of a rootkit virus that won't die... About ready to go Mac.) Searching for these objectives on ebay I clicked on a link within one of the listings and now I'm in pc hell.

ChrisR · Post by **ChrisR** » Sun Apr 11, 2010 3:25 pm

Well I suggest you browse through the Nikon and Olympus microscopy sites, for background info. You would find in the reference I gave for instance, that

DIC objectives are not modified internally

and pile of stuff about prisms and so forth.

Try googling
dic +objective +application
- and there's always
http://en.wikipedia.org/wiki/Differenti ... microscopy

The answers are always so much longer than the questions.

more experienced guys like you and Charles

Charles and I are barely orbiting in the same solar system of experience. I just try to chime in on a few of the easy questions, and leave Charles, Rik and others with the harder ones.

Enoplometopus · Post by **Enoplometopus** » Sun Apr 11, 2010 3:57 pm

>>The reason I say "assuming" is only that Nikon's CF brochure does not illustrate that particular lens, so I can't be sure what it is.<<

Wow, you make me worried. I'll wait and see...

>>I'm starting to really envy you ;-)[/quote]
Yes, it is a wonderful thing to have a spouse who tolerates my quirks.

<<

Well, actually I can join that club...

>>It would not be extreme to describe me as "well experienced in failures". This is to be envied?<<

Yes, it is. Simply because we humans only learn from mistakes. We never learn from success, only from failures. And your "experience in failured" is the base of your knowledge. And that is certainly something to be envied ;-)

Thanks for the text results, that sounds great. Just in case the objective I bought is not what I expect it to be, i know what to buy...

Cheers, Daniel

--Rik[/quote]

rjlittlefield · Post by **rjlittlefield** » Sun Apr 11, 2010 6:15 pm

bklein wrote:Also, Nikon has the CFI60 series scopes with objectives referred to as CFI and CFI60 (which looks a lot like CF160).

Since I took the time to look it up...

Nikon's CFI60 designation refers to a color-free infinity objective with a 60 mm distance from mounting threads to in-focus subject. See HERE for a full description.

--Rik

bklein · Post by **bklein** » Thu Apr 22, 2010 8:45 am

Back to this "dead horse"...
Searching ebay on "Nikon" and "m plan" I come up with perhaps 3 or 4 different physical styles. The new knurled barrel ones are obviously nice and definitely CF. But the others I've not read whether they all are CF or just some. All I'm discussing would be established as finites. In particular there is one that has a smooth barrel with ribbed ring right at the threads. Like this look:
ebay 280449535322
When people are making comparisons in this forum of the "M PLan 10" are they referring to just the latest model?

rjlittlefield · Post by **rjlittlefield** » Thu Apr 22, 2010 10:33 am

It's not so much a matter of "latest model", but "different model".

The unit that I have and that I write about is an N Plan 10X NA 0.30 160/0.17, optimized for visual quality on a biological scope under cover glass.

The one you're looking at is an M PLan MI 10X NA 0.25 210/0, optimized for a particular instrumentation task on a metallurgical scope with no cover glass. It has a smaller aperture [not so good] and is designed for a longer tube length (210 mm vs 160 mm) [different], with no cover glass [better], and for a different task [possibly an issue].

Notice in the advertisement that it says: The MI multiple beam (Tolansky) objectives provide higher measuring accuracy, down to 1/100 of the wavelenght (approximately 5nm with 540 IF Narrow band filter), due to their sharper fringes. They utilize a reference mirror which must be brought into direct contact with the specimen. By itself this is pretty scary.

However, the mirror they speak of is not part of the objective. See http://www.photomacrography.net/forum/v ... php?t=9419 , where Craig (augusthouse) says that the WD of the objective alone is 12 mm and shows an image that looks good clear out to the corners.

--Rik

Edit: fix typo in designation: "N Plan" versus "M Plan"