Setup for specimens in water on a research vessel?

[kmkocot]

Hi all,

I am an invertebrate zoologist and my lab will be on a ship-based expedition to Antarctica this November. We will be sampling marine invertebrates and I would like to be able to take nice images of specimens in shallow dishes of water or petri dishes. We have a microscope with a camera for *really* tiny things but I'm looking to design a setup to take nice photos of relatively larger specimens on the order of 1-10 mm in size. I should note that we use dishes with the bottom painted with Black 3.0 paint for most of our photos but sometimes a white background is preferred. The ship tends to have a lot of vibration (so as much as I would like to do focal stacking, that is out of the question) and portability is a somewhat important consideration.

Can anyone recommend a relatively portable camera stand / microscope-style mount and/or lighting situation for shooting down into dishes of water that will reduce glare from the water's surface? I was wondering if anyone has experience with using a lightbox with their flashes pointed upward or using another source of extremely diffuse light for imaging specimens in water?

I currently don't own any gear but am considering purchasing a Canon mirrorless body because a colleague of mine has a lot of lenses he could loan me. If I were to do that, any recommendations on lenses for this application? Depth of field is somewhat important for me as we will be doing somewhat high-throughput documentation of specimens.

Thank you!
Kevin

[Lou Jost]

I wouldn't worry about the glare. That has never been an issue for me. The lighting is never so axial as to cause glare, because the lens is in the way.

For such a wide range of subject sizes and given the need for a fast workflow, I'd recommend the Laowa 2.5x -5x as one of your lenses. Perhaps even better for you is the much more expensive Canon MPE-65 because it goes from 1x-5x). To shoot through water you will have to stop both of these down. How much depends on the depth of water. You'll be stopping down anyway because of your single-shot workflow, so that's not an issue. But you shouldn't expect to get very sharp images of 1mm subjcts if you have to stop down much.

You can get away with stopping down less if you use a reversed Micro Four Thirds lens mounted on a Canon zoom lens. See my discussion here:

https://www.photomacrography.net/forum/ ... sc&start=0

https://www.photomacrography.net/forum/ ... ting+water

The zoom tube lens would give you some flexibility for field of view, though less than you would expect, because the zoom vignettes at lower magnifications. I don't have experience with Canon zooms so maybe someone else can give you hints about a good zoom to use. No matter which one you use, the useful zoom range will be much less than the nominal range, but that can still be helpful if you have to work fast, especially if you are willing to crop the vignetting out later.

If you are stopping down a lot, and if you need a wide range of magnifications and can't spend time changing lenses, you could reverse a wide-angle zoom on a long zoom. Then you could zoom either or both, giving you great flexibility. But image quality would suffer compared to the options I mentioned. You'll have to weigh the importance of image quality versus the importance of speed.

[Ichthyophthirius]

This might interest you. The photographer uses horizontal and vertical setups (7:00), white and black backgrounds, and Canon 100 mm and MP-E 65 mm macro lenses.

https://www.youtube.com/watch?v=Ahfu7ZCs94A

[Rorschach]

The size range of your specimens is exactly the same as mine (benthic freshwater macroinvertebrates). By far the best tool for looking at them (and photographing) is a good stereo microscope.

[lothman]

may be this is interesting for you:
https://www.venuslens.net/product/laowa ... cro-probe/

but it is rather expensive

[elf]

You might consider an Olympus which does in camera focus stacking. I don't know if Canon has this feature.

p.s. Renting a camera and testing various lens would be beneficial.

[TheLostVertex]

You might consider an Olympus which does in camera focus stacking. I don't know if Canon has this feature.

p.s. Renting a camera and testing various lens would be beneficial.

I have an m6 mii, and it has focus bracketing, I am pretty sure the 90d does as well. Focus bracketing on it works well IMO, with the caveat that you can not use flash with the feature. I am not sure if there are any cameras with focus bracketing that can use flash though. With a 100mm macro and close up filter I have been doing focus stacks somewhere around 2-2.5x without issue.

[Rorschach]

I would like to again emphasize the versatility of a quality stereo microscope. No other option comes close for that size range of specimens (and somewhat beyond that range).

At one point I spent time on a research vessel at sea doing bottom invertebrate sampling. There are some ways around the problem of the vessel moving due to wave action and the ensuing movement of specimens in water (or ethanol).

The trick for sampling and sample pre-processing on the rear deck during rough seas was a rope around ones waist!

[Lou Jost]

Two tricks for keeping very small things still in the water: mix with glycerine or add methyl cellulose. Or smear the bottom of the receptacle with glycerine and then add water, and embed the specimen in glycerine.

Hang the camera + microscope on a bungie cord and control the focus remotely with wireless? Some cameras now allow this. I imagine some high-end stereoscopes do too. Use an external monitor for display. I've never tried this so best to test first!

[Scarodactyl]

I would like to again emphasize the versatility of a quality stereo microscope. No other option comes close for that size range of specimens (and somewhat beyond that range).

A photomacroscope might be a better option if the goal is primarily photography rather than inspection. Maybe even one without eyepieces like a Navitar system if high resolution isn't paramount vs versatility. These can also be had pretty affordably.

[jcb]

The biggest problem, affecting quality much more than the optics may be the effect of ship vibrations on the surface of water (wavelets). Victorian microscopists (modern ones also, perhaps) used closed water cells (basically a more or less thick space between two glass surfaces filled with water and their specimen).

[Rorschach]

A photomacroscope might be a better option if the goal is primarily photography rather than inspection. Maybe even one without eyepieces like a Navitar system if high resolution isn't paramount vs versatility. These can also be had pretty affordably.

That is true if the only target is photographing things.

However, I have _never ever_ seen a zoologist (zoology was what I majored in during my MSc) who wouldn't want to look at specimens as well

There is something absolutely magical, sometimes even stunning, about the true 3D view that you get with a stereo microscope. One can be mesmerized by the views for quite some time.

Of course, there are also compromises between a macroscope and a stereo microscope: a stereo microscope that has an objective that can be slid to axial position. As you know, these are much better for photography than other stereos. Especially if an PlanApo objective is in use.

[houstontx]

I've always like Kurt Maurer's solution here (almost bottom of the page):

http://sawdustfactory.nfshost.com/microscopes/

Hes mounted a stereoscope horizontally to look through a small fish tank. Maybe a similar smaller setup can be made. Click on the flickr link at bottom to see example images.