Inquiry about Lomo 10x 0.40 achro lens - I looking for a 10x lens for macro

[fdupre]

Hello everyone,

I allow myself to ask you about a microscope objective: Lomo 10x 0.40 achro RMS 160 mm
More precisely on its use on a macro bench.

Lomo_10x_0.40.jpg (87.17 KiB) Viewed 1964 times

Does anyone know this lens in the macro area at 10x magnification?

Thank's a lot in advance for your feedback.

Sincerely,
Franck

[fdupre]

I got my answer about this lens and its use in macro;
I was given a site:
https://rafcamera.com/lomo-microscope-o ... minescence
which indicates that the working distance is 3 mm.
I was interested in buying it but so the working distance is too small for macro I think.

I will continue to look for a 10x suitable for macro that is not too expensive (below 200 dollars at the most would be perfect).

If you have any advice. . .

[Chas]

frank, its always worth bearing in mind what can be achieved mechanically in terms of stability and step size.
The step size to avoid banding with an N.A 0.4 objective is very small, See table 2-C (at the bottom of the webpage) here:
https://zerenesystems.com/cms/stacker/d ... romicrodof

Maybe a good idea to have a go with an ordinary 10x objective (off your microscope?) to check for general/unexpected problems?

[apochronaut]

Higher N.A. objectives always have shorter working distances, although 3mm is not bad for .40. Efforts have been made to produce such with longer working distances but at usually great cost.
At the .25 standard N.A. of most 10X achromats , the magnification to total magnification limit ratio is quite high at 25, even higer than that of a high resolution 40X .85 objective, so uless you are expecting to achieve very high overall magnification from the objective the value of the higher N.A. might not be there.

What working distance is required because some .25 planachromats I know of are 9mm.

[Scarodactyl]

Yeah, at 0.40 fairly long working distances are possible but only fairly specialized objectives attain them like the Mitutoyo 20x/0.42 m plan apo. For a 10x/0.40 it's very rare indeed. I briefly had a Mitutoyo HR 10x/0.42 with a working distance of 15mm, spectacular objective but it didn't work with my epi DIC slider so I passed it on. It does have some benefits over a more common 0.25 na 10x but the narrower DoF is inconvenient too.

[fdupre]

Very very very good microscope objectives the Mitutoyo but given the prices I already hear my financial management at home who would tell me this:

rrrrogntudjuuuu.png (164.63 KiB) Viewed 1832 times

[apochronaut]

Yes but Mitutoyo aren't the only options in fine 10X microscope objectives with a longer working distance. Mitutoyo are also infinity corrected. If infinity corrected objectives are o.k. with you, then there are many other cheaper options and plan too. Most would be optically as good or better than your Lomo choice which is not plan. There are also many 160mm options that have an extended w.d. and some would be plan, an important consideration if you are intending to photograph thinner samples.
If you provide the w.d. you are looking for, some suggestions could arise from that.

[fdupre]

Hello everyone and thanks fir your precious feeback,

@ Chas: following your wise advice, I did a test with the 10x objective of my microscope (Bresser 10x achro plane infinity):
shooting :

pdv600px.jpg (88.24 KiB) Viewed 1802 times

araignée_canon70-200_Bresser10x_MH.jpg (218.82 KiB) Viewed 1802 times

In terms of step size, I think I'm good but in terms of stability I think I'm at the maximum of the possibilities of my bench.
I must also say that the room in which I take my macro photos (my office) has a parquet floor! and is on the 1st floor. I think it's really not ideal for vibrations but hey, I can't change offices.


@ apochronaute: I confess that I did not understand you well (I am a beginner) but the term "wd" means "working distance" i think. From my little experience 10mm working distance would be good and more would be better but definitely more expensive i think.

Here is the working distance I get with the Bresser 10x achro plan infinity objective of my microscope screwed on a Canon 70-200 L f2.8 set to infinity and open to f2.8 :

work_distance_text.jpg (79.42 KiB) Viewed 1798 times

If you have any suggestions (cost: 200 dollars maximum please), they will be really welcome and really, thank you for your help apochronaute

Sincerely,
Franck

[ADi]

Hello Franck,

I don't know if the WD is so crucial.
I took a similar spider with the cheap Nikon BE Plan 10x/0.25 WD 6.7.
The resolution was so good that you can recognise the feather hairs:


https://live.staticflickr.com/65535/495 ... 734c_o.jpg

Best, ADi

[fdupre]

Hello ADi and Thanks for your return,
this is the one you're talking about ?
https://www.ebay.fr/itm/304709187431

[ADi]

Yes, exactly.

(But Mitutoyo is better

[apochronaut]

I'm thinking that using a longish camera lens for a tube lens will alter the objective's w.d. anyway and as well might detract some from the objective's performance. With subjects that fill the frame, corner sharpness becomes an issue, a well known distortion when using a camera lens for micro subjects, hence cropping. I use a really old 160mm tube Beck 40mm apochromat sometimes for macro. I made up a hollow 160mm tube for it and with that it should be about 4X at the sensor. It will cover a larger APS-C at least and it gives very good crisp images. It has a ridiculously long w.d. in the 30mm range. Many older lower magnification objectives have lots of w.d. and if you can find an apochromat, there is quality enough to allow for cropping. Might be an option closer to a modern Mitutoyo but cheap. You could liberate your camera lens and cut down on vibration.
You said that 3mm was too little but for a 160mm objective. Hard to know how that would have performed in your system, which has a pretty long optical path filled with lenses.

I just wanted to know what was enough for a w.d. There are a lot of options in the 5mm and up range. That Nikon BE Plan looks pretty o.k. and cheap too but bear in mind that the image posted by ADI uses a different lighting setup and probably doesn't use a camera lens as a tube lens. Maybe they could clarify what was the set up.

[ADi]

Might be an option closer to a modern Mitutoyo but cheap.

For reflected light, the Mitutoyo has no competition.
For transmitted light there is the Nikon Plan Apo 10x /0.45

I just wanted to know what was enough for a w.d.

I can manage 1 mm

the image posted by ADI uses a different lighting setup and probably doesn't use a camera lens as a tube lens

Yes, the difusser was a little different but the tube-lens was the Canon EF 70-200L.

BTW, Nikon BE Plan 10x/0.25 is good for crop, Mitutoyo M Plan Apo 10x/0.28 also very good for FF

[zzffnn]

The LOMO 10 / 0.4 is not a good lens for macro, it has been tested by a macro photographer at the other forum before.

Usually around 3mm or more working distance is workable, if objective has a sharp tip.

[fdupre]

Thank you for your very very interesting feedbacks.
@ADi : I bought the Nikon BE plan 10x lens. For 60 dollars including shipping it would have been stupid not to do it.
Sincerely, Franck

[ADi]

I bought the Nikon BE plan 10x lens. For 60 dollars

congrats !

[apochronaut]

Thank you for your very very interesting feedbacks.
@ADi : I bought the Nikon BE plan 10x lens. For 60 dollars including shipping it would have been stupid not to do it.
Sincerely, Franck

Probably a good choice for that amount of money. It is truly amazing what you can find in inexpensive superb imaging microscope objectives if you shop buy carefully.

[fdupre]

Hello everyone,
Nikon BE plan 10x lens received : Here is a first test: https://www.microbehunter.com/microscop ... 79#p138179
thank you all for your advice. because the lens has a very good resolution I find.
Kind regards,
FRanck