Dare I mention Russian stuff.

[apochronaut]

I brought this oddity about a Russian( maybe Soviet?) seemingly iris equipped objective up a while ago. Seems they needed to use up existing parts. Below is a recap but then there is more.
I am in the process of filling out a third nosepiece for a PZO Biolar. Ultimately the stand will have 3 swapable dovetailed 5 objective nosepieces : DIC, Anoptral phase contrast and this one ; intended to be as much as possible a planapo set with an iris equipped 100X in order to accomplish high rez DF. It is hard to find a planapo iris equipped objective for anything short of a King's ransom , so my thoughts turned towards Lomo : likely topping out at 20mm f.o.v. max. but good enough and hopefully cheap enough to be affordable, An iris equipped planapo turned out to be elusive but I purchased an iris equipped 45mm parfocal 160mm tube length fluorite 100X 1.30 objective on ebay but when it arrived it was marked infinity. The oo version and the 160mm version look identical, except for that designation. After an email, the seller apologized for the mistake but indicated he had no 160mm versions and offered a refund. This, though the pictures in the listing clearly showed 160mm inscribed on the barrel.
The image produced by the infinity version was poor in the 160mm scope and equally as bad in a Reichert infinity scope, which I put down to a difference in reference length and telan lens requirements. It had an odd bleeding flare about it with weak resolution and poor contrast. A couple of weeks later and a surprise package containing the same objective in a 160mm version arrived. No charge and no comment from the seller. If only all ebay merchants were that way inclined.
There was one additional problem though. Even though the objective was identical to the infinity version, even down to having the aperture opening triangular graphic on a graduation ring, it in fact did not have an iris diaphragm. The quality of the image was good to excellent but no iris. Useful but not really what I intended.
Since the two objectives were so similar, I reasoned that perhaps I could put the iris from the infinity corrected objective into the 160mm version. Breaking down the infinity objective, I found that it was in fact fouled with immersion oil. Maybe that was the source of the image problem? I cleaned it up, reassembled it and found that it's image in a 160mm stand was as good as that of the 160mm version. I then broke down the 160mm objective. The two objectives turn out to be optically identical and perform equally well in the 160mm stand. I can't explain this except that perhaps Lomo designed what I call a modified infinity system, where a compensating optic is placed in the stand in order to adjust for "infinity" space accessories and then a further optic downstream completes the process, as a telan lens would, producing a convergent beam. . Thus 160mm objectives could be used but are marked infinity in order to have a coordinated system.
The two objectives below look like identical Russian howitzers awaiting the ejection of their loads but they are in fact similar microscope objectives, different in the name of the tubelength only.
F.Y.I. The Lomo planapos and fluorites work perfectly with Olympus W.F. 10X Bi. eyepieces such as were used with the Olympus shorty planapos. 18mm f.o.v. with an ever so slight bowl effect, rather than a truly flat field.

For anyone looking for a highly corrected 45mm psrfocal 100X objective with an iris diaphragm, these are a very economical option and you can buy either the 160 or the infinity version and it will work well on any 45mm parfocal microscope with a 160mm tube length and provide excellent imaging. They are fairly commonly available. There is even a U.S. seller with some of them. Just make sure that you confirm that it has the iris diaphragm installed not just the registration mark. If you look at the two pictures, the one with the iris diaphragm( oo ) also has a black knurled ring that actuates the iris diaphragm. The other ( 160 ) just has the chrome threaded collar. Both also have a mechanism of parfocalizing them to other objectives by moving the internal lens housing up and down in the outer barrel.

[MicroBob]

Hi Phil,
interesting story, thank you!
Is it possible to unscrew the the outer sleeve with the labeling? There were 33mm Lomo 90:1s where it was easy to convert an achromat into an apochromat by simply exchanging the sleeve!
I once bought a 70:1 1,23 water immersion objective from a professional dealer - delaminated in multiple layers. I asked for a proper one and got one that was even worse. It is quite possible that boxes full of damaged parts find their way to ebay from time to time.

Russian microscopes would be quite a nice field for a collector, very detailed program and many rare bits to look for a life time long.

Bob

[apochronaut]

Yes, I could likely swap the engraved shrould one for the other. I never checked to see if I could for sure , just whether the entire lens pack or iris could be moved over. That shroud freely rotates and is held in place by a chromed threaded brass collar in one case and a black plastic collar integrated with a long channeled sleeve to actuate the iris drivepin under it , in the other. The barrel is different for each with the iris version having a lateral channel cut for the drivepin, so were I to have integrated the iris from one with the lenses from the other, it would have had to be in the original barrel marked infinity.
The objectives are both fully coated with 6 lens cells in each, doublets in most cases ; 4 below the iris and 2 above. The space for the iris is taken up with a spacer in the plain one. The only differences I can see is that the cell around the very back lens in one is slightly thicker walled and the return springs are different lengths.
The image quality; resolution and contrast is about as good as an AO Spencer(uncoated) 97X 1.30 fluorite from the mid-50's but with better planarity. The fluorite characteristics are evident and I would grade them as semi-plan.

I have seen multiple examples of those objectives on ebay , most from Russia , Belarus or Ukraine. The U.S. seller that has(had?) some versions marked 160mm sent me photos to prove the existence of the iris and one seller in Russia had a 160mm with the open/close mark on it but no iris. About 1/2 of the ones I looked at were marked infinity and 1/2 160mm, otherwise the objectives appear identical.

[Hobbyst46]

A stupid question: the engraved/printed marks on the Objective, in Russian, are readable by users from the USSR, Greece and some Eastern Europe countries, but did Lomo ignore Western export markets ?

[apochronaut]

Optics Planet distributed them in the U.S. and some of the objectives I have seen from them had English markings but probably for most of their Soviet production they sold so little outside of their sphere of influence that it wasn't worthwhile. There is also the " you wyii doo it owr way" factor. The English marked stuff was post Soviet and what I have seen had painted barrels.
Lomo also did custom branding. I know of one instance in France, anyway, en Française.

[jmp]

Some thoughts about this.

First, I second MicroBob's suggestion that perhaps the sleeves were swapped. I have a couple of Lomo 40x objectives, one for use with and one for use without coverslip:

20220330_170627_small.jpg (75.21 KiB) Viewed 2219 times

I was puzzled by the poor performance of the coverslip version, until I got around to compare the images I obtained from each... and it was clear that their sleeves were swapped. It made sense, both objectives came from the same source.

Second, I do have the infinity version and a relative of the finite version, in its quasi-planar version (non-fluorite), of the fluorites that you have. Both share the same barrel, and iris:

20220330_170547_small.jpg (83.23 KiB) Viewed 2219 times

Note that these have a white ring, while yours have a green ring. Removal of that ring lets you remove the sleeve with the description of the objective characteristics. The difference in color might be relevant because I've seen this:

IMG-20200803-WA0010.jpg (44.27 KiB) Viewed 2219 times

That's the lineup of Lomo's fluorite infinity corrected objectives: both 100x objectives have a white ring, while the green ring is on the 20x (which, by the way I would really like to find, as well as the 40x/0.85 non-phase). In any case, in my opinion the color of that ring might be an indication of previous tampering, which increases the likelihood of a sleeve swap.

[zzffnn]

That makes sense, since green is usually the default label color used for 20x objectives, and white for 100x, even though none of my many LOMO short 160TL objectives are color coded.

Also, I would guess the second free objective apochronaut received was free, because it may not be the original version (may or may not work / unknown to seller).

I also had a 160TL 34mm parfocal LOMO 60x NA 0.85 objective that looks to have clean and clear glasses in hand but performed very terribly on scope. Seller refunded me. I don’t know if there is a similar looking infinity version or if it has been swapped; never had a chance to compare. No worries though, as I stopped using high dry objectives all together.

[apochronaut]

That's a pretty impressive group of fluorite objectives.
Well, every Lomo fluorite 100X I looked at had a green ring and they were being sold by 3 different sellers in 3 different countries. The U.S. seller had quite a few at one time , purchased surplus I believe from some company that had them as objectives to use in DF. If you look closely at the 100X objectives, the coloured ring is smaller and needs to be held on with a further chrome ring, exactly the same design as my green ones. The lower power objectives have an entirely different style of ring which wouldn't fit on the 100X, due to the wide diameter of the bezel and the narrower i.d. of the low power code rings.
Neither of the objectives I disassembled showed any sign of having ever been disassembled. One very telltale sign would be on the rear baffle/springcap, which on those Lomos is very thin and has very shallow slots, plus the paint on it is micro thin. They were both in very tight and it is very hard to remove them without slipping a bit and removing paint. I saw no evidence of any repainting and there was no paint loss either. In fact there was no evidence of either of them being disassembled anywhere.
While there is a a general agreement on colour coding for objective magnifications today, that was not always so. Colour coding of objectives started as an in house thing, sometimes adopted by more than one company that worked together, such as Baker and AO in the 50's. Up until 1985 AO had 2.5X purple, 4X, black, 10X green, 20X blue, 40X, yellow, 50X brick red and 100X red. Earlier, black was 100X. In 1986 they went with the modern convention. Likewise , Vickers used a similar colour scheme inherited from Baker. At Bausch & Lomb right up until the latest production in the early 90's when they were branded Leica, it was light blue 2.5X, dark blue 4X, green 10X, mauve 20X, yellow 40X , white 50X and red 100X.
I suspect that Lomo at one time used a different colour code sequence or even more than one. I have a 40X .70 Lomo shorty that is coded pale yellow. In the coding scheme pictured above it seems both blue and black are used and then in the first picture both the 10X and 40X are blue.

Here is the very same green ringed Lomo 160mm fluor objective for sale in the U.S., this time with an iris.

https://www.ebay.com/itm/LOMO-Microscop ... ect=mobile