Some attempts at polarised crystal pics (Aspirin)

[Aenima]

Hi guys - hope you're well.

Been having fun. Had a go at making a polarising mod with one of those filter sheets that can be cut into bits with scissors. Was a very cheap way to experiment with the technique. I think the little sheet cost me 10GBP off ebay.

As you guys will know, a piece went into the 'head' just above the objective turret, and the other piece over the lamp beneath the condenser.

The crystals were my first nearly-successful slide after some failed attempts with salt and artificial sweetener - -So i crushed an Aspirin in a spoon and added isopropyl alcohol and heated until dissolved, tipping the spoon to drop a small amount of the liquid onto a slide then heated with a lighter until it dried. Chemistry is not my best subject! haha. total novice (again!) i'm sure better ways exist, especially with regards to getting pure crystal without gunk and impurities remaining on the slide. (Suggestions welcome )

These were taken with a canon 1000D using eos movie recorder to record a few seconds of video footage as i turned the fine focus - i then converted into TIFFs before stacking them in CombineZP.

Several objectives were used, but i forgot to make notes - most used were a leitz 10x fluotar npl, and 25x leitz phaco both picked up on ebay for 'happy prices'

Anyway, they aren't exactly great, but i was just pleased to have gotten a result at all.

unpro9cpolpol.jpg (348.57 KiB) Viewed 2935 times

sdfg.jpg (462.94 KiB) Viewed 2935 times

pol4.jpg (475.65 KiB) Viewed 2935 times

pol3.jpg (430.37 KiB) Viewed 2935 times

pol5.jpg (483.25 KiB) Viewed 2935 times

[75RR]

These were taken with a canon 1000D using eos movie recorder to record a few seconds of video footage as i turned the fine focus - i then converted into TIFFs before stacking them in CombineZP.

Certainly works. I imagine it could be quite useful when used on those pesky critters that do not stay still for long.

[zzffnn]

Aenima,

You made beautiful crystal patterns, though somehow they are not very colorful. You did rotate your bottom polarizer, correct?

Maybe the lack of color has something to do with your crystallization method or related chemistry. I found that crystal that are too thick or too thin won't be colorful.

You can filter your solution with tissue paper to remove undissolved materials.

91% isopropyl alcohol is not available in UK, I am guessing? I have used that to dissolve aspirin and the resulting solution can quickly recrystallize by itself, without heating, through IPA evaporation.

If you can do remote- controlled slow sequential shooting at say 2 frames per second, you can activate that and slowly rack up your microscope focus drive (don't rack down focus, as objective may crash into sample). That does the same quick focus stacking as using video function, though it provides a bit higher resolution.

[Hobbyst46]

Aenima,
Pure or nearly pure isopropyl alcohol is highly flammable and will catch fire if placed near an open flame (from a lighter, match, gas). The pure liquid boils at about 82 degrees celsius, so you can safely heat it in a boiling water bath or over a small pot with boiling water.

[JimT]

You did rotate your bottom polarizer

I was going to suggest the same thing.

[Aenima]

Wow, some great ideas, thank you

A couple points stick out.

The crystals being too thick causing lack of colour. This might explain my problems with salt. Haven't managed to crystallize in a way that leaves thin layers. Also rather limited in equipment and ingredients not to mention skill

The rotation of the filter, i did have it set to it's darkest but once the camera was attached i messed around a little bit too much with the rotation in an effort to get different lighting and contrast. I do like the golden appearance, but it did seem to be the most abundant colour - will try filtering the liquid in hopes that a purer crystal will show more variation, or vibrant colour. (as well as keeping the polarizer crossed) i gave the sellotape slide a try between the filters for extra colour, but very unfamiliar with how to properly use it (possibly the cause of the overly gold images?) so yeah, i'm still trying to figure it out.

Also, the suggestion to use timed single shots instead of video - I didn't realize that the EOS movie recording the live view would be any different to shooting single frames. But did suspect the quality might be reduced, so it's handy to know.

I think aside from convenience and speed, the reason i used EOS movie was the trouble i keep having with Digicam control - for some reason it locks up after a few shots, and a 'canon error xxx' appears, and the LCD camera screen shows the blue swirl of waiting for transfer to complete - its like the images are piling up rather than being transferred smoothly. It means after 6 or 7 shots the software and camera need to be restarted. (tried the two options 'save to card and pc' and 'save to pc only' but no joy) i'm thinking my SD card might be faulty, or something like the USB cable - but thats a total guess.


ANYHOO, that's a whole different story lol - as for polarized light, i have some great suggestions to look into, thank you.

[Aenima]

Aenima,
Pure or nearly pure isopropyl alcohol is highly flammable and will catch fire if placed near an open flame (from a lighter, match, gas). The pure liquid boils at about 82 degrees celsius, so you can safely heat it in a boiling water bath or over a small pot with boiling water.

Yep! found that out the hard way! my eyebrows will grow back eventually