Stereo Zoom Microscope - What to buy?

[ojd01]

Hello Everyone!

I am looking to purchase a stereo zoom microscope - ideally with a DSLR attachment ability (trinocular or another method) - for larger "lumpy" subjects, where a compound microscope may not be as good and definitely do some stacking. Canon EOS would be the attachment also, I would imagine T-adapter of some sort and T2 ring?

I don't know very much about the good/bad brands or the things to look out for. Budget between £400-£600, maybe up to £1000 once I have sold some of my old photographic equipment. What would anyone on here recommend?

Thank you in advance!

Owen

[Ichthyophthirius]

Hi Owen,

What's been you experience with stacking so far?

In broad terms, stereo microscopes are not ideal for stacking because of the inclined optical axis (reduces image quality and stifts the image during stacking).

Alternative methods (low magnification: macro lens + focus bracketting; higher magnification: microscope objective) will give you better image quality at the same price point. You might get it to work if you already own a stereo microscope but if you're just starting out, it's not worth getting one just for photography.

Regards, Ichty

[Scarodactyl]

Yeah, stereo microscopes are the ultimate visual inspection tool but less ideal for photography. If you get a high quality stereo microscope you can get decent photos with it, but there are inherent limitations on resolution. If you want most of the ergonomics of a stereo microscope with better photographic possibilities you can aim for a photomacroscope. Realistically speaking the only affordable one is the Wild M400 series with a makrozoom objective, giving a 5:1 zoom ratio. Resolution and distortion correction is good and it covers aps-c very well but you get some axial CA on highlights. These systems allow you to have a parfocal zoom with good working distance and an upright image in the eyepieces just like a stereo, but with a single, higher resolution light path (so no 3D image).
There are in between solutions, with some stereo microscopes allowing you to offset the body or objective to one side to pull the image from the center of the lens. This could make sense if what you really want is a very good stereo with a side of photography but still want the best photos you can get.
Or you can go a step further yet and aim for a metallurgical microscope with long working distsnce objectives. Good for inspection and top notch for photography, not quite as comfortable as a macroscope but far more powerful.
Depending on your budget and needs one might be better than another. Or all three if you're feeling spendy.

[ojd01]

Hi Owen,

What's been you experience with stacking so far?

In broad terms, stereo microscopes are not ideal for stacking because of the inclined optical axis (reduces image quality and stifts the image during stacking).

Alternative methods (low magnification: macro lens + focus bracketting; higher magnification: microscope objective) will give you better image quality at the same price point. You might get it to work if you already own a stereo microscope but if you're just starting out, it's not worth getting one just for photography.

Regards, Ichty

Hello! Sorry for the delayed reply. I've done a lot of stacking with camera, extension tubes and 1:1 true macro lenses - I am very happy with what I get from that also.

I did try and delve into the camera + T-adapters + microscope objective and it wasn't working for me. Maybe, it might be the space restriction I had at the time, or that it was a very fixed unit I had. Also, I did struggle a little with the objectives I had (I think they are achromatic only, nothing semi-plan or plan , or special). I already own a compound microscope and enjoy using this for slides.

The stereo microscope I have been recommended by the company GT Vision is this one: https://www.gtvision.co.uk/GXM-XTL3T101 ... Microscope (currently not sold on the website but can be acquired new). This combined with a DSLR adapter for my Canon.

I feel I might need to look back into the camera + microscope objective setup + maybe a focus rail to improve the "bracket". I do still have the extension tubes and the objectives I currently have are 160mm tube, so were a bit of a pain to setup.

Thank you for your advice

Best Regards

Owen

[ojd01]

Yeah, stereo microscopes are the ultimate visual inspection tool but less ideal for photography. If you get a high quality stereo microscope you can get decent photos with it, but there are inherent limitations on resolution. If you want most of the ergonomics of a stereo microscope with better photographic possibilities you can aim for a photomacroscope. Realistically speaking the only affordable one is the Wild M400 series with a makrozoom objective, giving a 5:1 zoom ratio. Resolution and distortion correction is good and it covers aps-c very well but you get some axial CA on highlights. These systems allow you to have a parfocal zoom with good working distance and an upright image in the eyepieces just like a stereo, but with a single, higher resolution light path (so no 3D image).
There are in between solutions, with some stereo microscopes allowing you to offset the body or objective to one side to pull the image from the center of the lens. This could make sense if what you really want is a very good stereo with a side of photography but still want the best photos you can get.
Or you can go a step further yet and aim for a metallurgical microscope with long working distsnce objectives. Good for inspection and top notch for photography, not quite as comfortable as a macroscope but far more powerful.
Depending on your budget and needs one might be better than another. Or all three if you're feeling spendy.

Hello! Thank you for your response and sorry for the delay in replying back. The two stereo microscopes I have been recommended (by GT Vision) are the following below:

https://www.gtvision.co.uk/GXM-XTL3T101 ... Microscope (currently not sold on the website but can be acquired new).
https://www.gtvision.co.uk/epages/es141 ... ducts/UZ-1
Both similar units - but the XTL3T101 being slightly better in optical quality. I do not think they are metallurgical, based on price.

I feel the issue I had with the camera + t-adapter + t-tubes + microscope objective setup was the lighting, positioning and bracketing. Since I have an EOS 500D for microscope work, I would rely on a focus rail, which I could not afford at the time. Maybe the microscope objective to camera setup could be the better option for me - and I already have half of the equipment. I would maybe need an upright stand, instead of working horizontally, I found that very frustrating.

This has left me with a lot of thoughts, which is very good! I hate rushing into purchases and finding out it's not good enough.

Best Regards

Owen

[Ichthyophthirius]

Hi Owen,

Thank you for the clarification. I think the GXM is a none-starter. The magnification range you get is between 1x - 4.5x. At the higher end, these stereo microscopes optics are usually not very good; so the usable range is maybe 1x - 3x. There are many other affordable and superior optics available in this range (macro lenses, reversed lenses, low power microscope lenses like the Lomo 3.7:1 https://www.closeuphotography.com/4x-le ... 00-dollars).

The second issue is the focus mechanism. On this stereo you have a parallax, shifting the image while focussing and degrading the image:
http://www.microbehunter.com/microscopy ... php?t=1628
https://www.lmscope.com/en/Stereomikros ... on_en.html (link is explicitly not a purchase recommendation)
Software might be able to handle this, but I haven't seen a lot of people in the forum using such a setup.

So you either have to tilt your microscope by 7.5 degrees or build a new stage with a mechanism to move the object at an angle; all that to use some mediocre optics. It doesn't seem worth it.

For £800 you should be able to buy a second hand Stack Shot (complete systems are occasionally on eBay https://www.ebay.co.uk/itm/164533938180) or one of the mechanical options http://extreme-macro.co.uk/extreme-macro-stages/ , bellows, an enlarger lens, and the Lomo 3.7. And a second hand stereo microscope for sample preparation.

Regards, Ichty

[ojd01]

Hi Owen,

Thank you for the clarification. I think the GXM is a none-starter. The magnification range you get is between 1x - 4.5x. At the higher end, these stereo microscopes optics are usually not very good; so the usable range is maybe 1x - 3x. There are many other affordable and superior optics available in this range (macro lenses, reversed lenses, low power microscope lenses like the Lomo 3.7:1 https://www.closeuphotography.com/4x-le ... 00-dollars).

The second issue is the focus mechanism. On this stereo you have a parallax, shifting the image while focussing and degrading the image:
http://www.microbehunter.com/microscopy ... php?t=1628
https://www.lmscope.com/en/Stereomikros ... on_en.html (link is explicitly not a purchase recommendation)
Software might be able to handle this, but I haven't seen a lot of people in the forum using such a setup.

So you either have to tilt your microscope by 7.5 degrees or build a new stage with a mechanism to move the object at an angle; all that to use some mediocre optics. It doesn't seem worth it.

For £800 you should be able to buy a second hand Stack Shot (complete systems are occasionally on eBay https://www.ebay.co.uk/itm/164533938180) or one of the mechanical options http://extreme-macro.co.uk/extreme-macro-stages/ , bellows, an enlarger lens, and the Lomo 3.7. And a second hand stereo microscope for sample preparation.

Regards, Ichty

Hello!

Yes, I am feeling the stereo zoom is not the best way to go. The camera + objective sounds better.

I was considering this setup:

- Canon EOS 500D (probably change this later)
- T2 - EOS adapter (already have)
- T-tubes (already have) - since the Lomo is finite to 160mm - one I have: https://www.ultramacro.co.uk/profession ... -640-p.asp (without the Raynox at the moment)
- T2-RMS (already have)
- Lomo 3.7x (need to find one)
- This macro stage - https://www.ultramacro.co.uk/ultramacro ... l-19-p.asp
- This auto rail - https://www.ultramacro.co.uk/ultramacro ... r-15-p.asp (or a better / more affordable for price one)

I have attached some images of the macro rail and stage. I think this will be a good starting point and having the vertical stage will use less space. I haven't looked into bellows and enlarger lenses though, that might be the next stop!

https://www.photomacrography.net/forum/ ... ew&id=2896
https://www.photomacrography.net/forum/ ... ew&id=2896

Kindest Regards

Owen

[Pau]

All this seems good, although I before would check the prices at the original makers sites. Wemacro, Zerene, Helicon focus, etc all have their own sites with direct sales.
I don't know www.ultramacro.co.uk but they seem just resellers

[JKT]

Lomo is finite, but it works even better as infinite.

On full frame with 120mm Gretag the sharp area was about 80% of image width and on DCR-250 it was about 30mm diameter. APS-C circle is about 27mm, so based on the latter, 112.5 mm tube should be sharp corner-to-corner. If you don't care about extreme corners, 100mm or even 90mm might do. Those are based on apparent sharpness on EOS RP, so it might not appear quite as sharp on APS-C sensor with smaller pixels.

As finite, it doesn't work that well on full frame due to limited image circle. The usable range starts from above 5, so I don't have enough data to predict APS-C behaviour.

[ojd01]

All this seems good, although I before would check the prices at the original makers sites. Wemacro, Zerene, Helicon focus, etc all have their own sites with direct sales.
I don't know www.ultramacro.co.uk but they seem just resellers

Don't worry! I have definitely been looking and there are a few resellers with good values. The original makers slap a £95 delivery fee so that doesn't help.

Got some kit on it's way

Owen

[ojd01]

Lomo is finite, but it works even better as infinite.

On full frame with 120mm Gretag the sharp area was about 80% of image width and on DCR-250 it was about 30mm diameter. APS-C circle is about 27mm, so based on the latter, 112.5 mm tube should be sharp corner-to-corner. If you don't care about extreme corners, 100mm or even 90mm might do. Those are based on apparent sharpness on EOS RP, so it might not appear quite as sharp on APS-C sensor with smaller pixels.

As finite, it doesn't work that well on full frame due to limited image circle. The usable range starts from above 5, so I don't have enough data to predict APS-C behaviour.

So you are saying shortening the tube length would increase the sharpness a little for APSC/FF? The 500D might not be as good, definitely not as good as the RP ( ). I have some tubes which I can assemble, disassemble to the length I need which is useful.

The other consideration is the Amscope 4X Plan Objective - 160/0.17 (https://www.amscope.com/4x-plan-achroma ... ens-1.html), which I have done a lot of research on. For 21.99USD + VAT + Delivery, it seems like a good steal. Hoping to find one to buy new or second hand in UK so I don't have to pay all the extra, as such.

Hoping to get all the new equipment end of next week, so I will give it a go and have a play!

[JKT]

Note that I was mostly talking about tube lens length when LOMO is used as infinite. When used that way, shorter tube will always result in sharper image ... at the center. It also means that in order to fill your image, you need larger image circle from the objective. This additional area can be unsharp or totally black if it is outside the image circle completely. In some cases the limiting factor can be the aperture in the tube lens as well. I estimated that with roughly 112.5mm tube lens, the corners would still be relatively sharp. Using shorter tube the sharpness at corners would begin to fail fast.

When it was used as finite (=extension tubes only), it needed 133mm extension (from T2 flange to RMS flange) in order to reach 5x. At shorter extension the corners on full frame were too bad ... for me. Corresponding magnification on APS-C would be 3.12x. You can approximate the required extension for any maginification from that 133mm at 5x: just subtract 33mm for reducing 1 from magnification. So 4x would be 100mm and 3x 67mm.