The next step was to get some photos – it’s all very nice cooing at your desk, calling over your long-suffering partner to have a look – but the idea was always to take pictures.
My first approach was to use a modified webcam. I use this for astrophotography – it’s just a Phillips webcam with the case partially dismantled and the optics removed, attached to a 1.25” adapter for fitting into an eyepiece tube.
Unfortunately I didn’t find this at all satisfactory. I couldn’t find a suitable point to introduce the adapter to the scope tube; I could mount it directly above the eyepiece, but the image was poor, and I struggled with the colour balance of the webcam (a problem I don’t see in astro work). Perhaps with a custom adapter tube it would work, but I didn’t have anything suitable to hand.
I fell back on another technique from astronomical imaging – afocal eyepiece projection. This is a grandiose term for what amounts to pointing a camera into the eyepiece. While not a permanent solution, it did at least provide some images, and a few minutes in Photoshop produced examples of white and XPL images side by side.
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Ok - they’re not going to win any prizes. But they do show that the basic technique can be achieved pretty easily, with very inexpensive materials. The scope originally cost about £40 including a set of blank and prepared slides, cover slips, etc. The polarising film cost a few pounds, and the camera was just a standard digital compact. It’s also worth pointing out that even with this crude setup, the visual results were very pleasing – much clearer than the photos.
Next steps? Well, I’m sufficiently encouraged that I’ve ordered a second-hand Olympus microscope and some proper glass filters. I need to find some meteoritic sections to examine, and look forward to seeing what a step up in quality can do.
Oh, and talking of quality... about two days after I took these images, I realised the polarising film wasn’t being scratched, and wasn’t delaminating. I just hadn’t realised that it came with protective plastic film on both sides.
Removing this led to somewhat clearer images, and a slightly redder face :-)
Mark Crawford