Lomo 2.5 - 0.05 Experience

Phil973 · Post by **Phil973** » Thu Oct 10, 2019 2:31 pm

Hi,

Does any one have experience with the Lomo 2.5 - 0.05?

A friend gave me one yesterday and at first sight it shows a lot of chromatic aberration.

I try this lens on a PB6 bellow with +/-160mm extension, images are really not sharp, working distance is very short btw.

I'm just curious of the settings if someone use this lens achieving fair results.
I search in the forums as well as online, it seems there's not a lot of info.

Thanks in advance

ray_parkhurst · Post by **ray_parkhurst** » Thu Oct 10, 2019 3:21 pm

Most low power microscope objectives don't work particularly well for photomacrography. I've had good luck with the Olympus M Plan 2.5, but otherwise all the objectives I've tried below 3x have been a disappointment. Even the Mitutoyo M Plan Apo did not do well vs some other lenses in the 2x range. I guess the tradeoffs to fit within a parfocal or nearly parfocal microscope environment are detrimental to IQ.

Phil973 · Post by **Phil973** » Thu Oct 10, 2019 6:22 pm

ray_parkhurst wrote:Most low power microscope objectives don't work particularly well for photomacrography. I've had good luck with the Olympus M Plan 2.5, but otherwise all the objectives I've tried below 3x have been a disappointment. Even the Mitutoyo M Plan Apo did not do well vs some other lenses in the 2x range. I guess the tradeoffs to fit within a parfocal or nearly parfocal microscope environment are detrimental to IQ.

Hi Ray, thanks for your answer, have you any recomendation within the 1/3x?

ray_parkhurst · Post by **ray_parkhurst** » Thu Oct 10, 2019 8:20 pm

Phil...have you looked over the recent tests done by Robert OToole at magnifications in this range, or at my own shootouts? You can glean lots of info on what performs well and what to avoid.

DimaDD · Post by **DimaDD** » Sat Nov 23, 2019 5:05 am

Dear Philip,

We've bought one LOMO POLAM-L213M microscope recently for our lab (as a good inexpensive workhorse) and I'm seeking solutions now how to attach mirrorless camera to its trinocular output (with image covering full APS-C sensor).

This objective (PLAN 2.5/0.05 P) is included in the standard kit. LOMO representative informed me that correction of chromatic aberrations in this POLAM is performed in eyepieces and C-mount 0.5x adapter (the only adapter in the box), that is why this objective (and all others designed for this POLAM) shows extensive color fringing if used alone.
So, modern LOMO objectives (at least part of them) are not suitable for simplest DIY constructions

. My own tests also confirmed this.
Hope this information is helpful.

Regards,
Dima DD

Lou Jost · Post by **Lou Jost** » Sat Nov 23, 2019 6:30 am

I also have the 2.5x objective, and when used on a camera, it sucks. For photography in the range 2.5x to 4x for full frame, I currently really enjoy the Laowa 2.5x-5x zoom, for its convenience. The ability to change magnification easily is a huge advantage if you have to take pictures at various m. Although lens combos are better at particular m, you have to change lenses for each new m, and it is hard to fill the frame exactly with any given combo. You can do that easily with the Laowa, and it is sharp all the way to the corners of FF and has no obvious optical problems. At the high end of its magnification range you could do better with other solutions, but it is very useful even up to 5x.

For 1.5-1.8x the Dimage 5400 is very hard to beat. You can also vary the magnification very easily by changing extension.

You can get that same ease of changing magnifications, though with a more limited range, by using lens combos and a zoom tube lens. Zooms tend to vignette at their lower focal lengths, but this can be reduced by using a zoom designed for a larger-format sensor. So a good FF zoom works well as a tube lens on MFT, and a medium format zoom works reasonably well with FF.