Thanks for your pm Jennifer.
Myxomycetes are quite sturdy when mature, so I do not have the problems you are encountering most of the time. However, immature plasmodia are very sensitive to light and dessication and I have managed to photograph them using the same setup.
For sensitive specimens I would store them in a cool garage on wet moss or paper towel until needed - only bring them into a centrally heated house when necessary. Working quickly is an advantage I think.
I always use a simple circular diffuser made from a single sheet of A4 folded lengthways and stapled (shown opened in the picture above). This give a large circle around the sample and protects it from heat to some extent.
I started using Jansjos but prefer one Trond flat panel either side - I prefer the colour and diffuse light. These are OK up to around 2x on an MP-E 65.
For higher magnifications I use a single flash aimed at the outside of the paper and synced to the camera flash (in a darkened room - I set up using Tronds first). I think this is currently my preferred method.
Camera is a Canon 70D in silent mode. All settings are manual. I almost always have the MP-E 65mm set at f2.8 and change exposure by adjusting flash power (between 1/4 and 1/32 usually with shutter often around 1/30 sec or faster) or by adjusting shutter speed in case of continuous lighting (between 1/4 and 1/30 sec normally).
Focus is adjusted using the E100 microscope base and all stacks are done manually by eye. You soon get a feel for how much to turn the focus control for a given magnification (i.e. 2x would be approx one rotation between shots). I view on live view and watch each photo as it arrives to the computer to check focus position. I wouldn't worry to much about calculating your depth of field - you can see as the photos appear if you have what you need.
In my experience the MP-E is much easier to use than an objective on a tube lens. Sometimes I get better results at a lower magnification and cropping the part of interest.
Starting with an easy inanimate subject at lower magnification and gradually increasing difficulty would be my approach. I'm not sure automated focus is necessary.
I hope this helps.
John
P.S. I couldn't bring myself to decapitate an E100 so bought a steel plate from ebay, drilled a couple of holes in it and just screwed it in where the slide holder was. This has the advantage of still being able to use the XY stage controls for fine adjustment. The heavy box of microscope slides is critical in keeping the steel plate flat. Specimen rotation is acheived by sitting the petri dish/slides on a glass plate.
P.P.S. Here are some images of a developing plasmodium from an earlier post which survived photography - see page 3
http://www.photomacrography.net/forum/v ... s&start=30
