I needed to make something portable to do wide filed imaging away from the observatory. So I decided to make a motor driven mount from the left over’s I had laying around.
The old german equatorial mount is from a 1972, 4” reflector. The tripod which is very sturdy, is an old field survey tripod. The drive motor is a 240v synchronise motor 1 rpm, this was used to stir chemicals. Large white drive wheel, is a plastic wheel from the hardware store, which I turned down and grooved to take a rubber belt for the drive.
The camera mount is constructed from a car mirror ball hinge, and the finder scope is a 50mm binocular lens, housed in pvc pipe fittings. Counter balance weight is a flat belt drum pulley.
I used it last night for the first time, and I’m quite happy with the results. I roughly polar aligned, and managed shots up 210 sec each. Of course there is some star trailing, but I’ll sort this out with better polar alignment, and refinement of the drive speed. The best thing of all, it only cost me a can of spray paint.
Images,
Orion, 3 x 210 sec exp, Canon 1100D 18mm lens at f/5.
Eta Carina rising 5 x 90 sec exp, Canon 1100D 18mm lens at f/5.
OK.. here's the challenge: Barnard's Loop: Your DSLR vs my little Panasonic LX5. Single frame only, no stacking.
Prizes ? Hmm... Only the glory of the best image.
I have a slide taken 30 years ago from Mt Bowen, on Ektachrome 200 with a Pentax SLR with 50mm f/1.7 that captured Barnards Loop very nicely in a 15 minute exposure. With the latest firmware I suspect Barnards Loop is just within the grasp of the LX5 - without a tracking mount, just a fixed tripod. With the LX5 my maximum exposure is 4 minutes at f/2. For the lens, I'll shoot at either 17mm or 24mm (35mm equivalent) at f/2.
I'll stay silent on the question of ISO, my answer will probably be a big surprise.
You have a tracking mount and a DSLR with a far bigger sensor (less noise) but a slower lens, so it should be reasonably easy for you.
PS Take your time. The weather in Sydney has been utter crap for weeks, so it will be next year before I get a chance in dark skies without the moon.
Hmmm!... isn't Barnards Loop already there?
In fact, I could be wrong, (I often am!) but the is some fuzziness not far from rigel that may be the Witch Head?
Malcolm
PS Ah I see, the challenge is for single exposures, sorry!
Hmm... Nope I don't see it. (/me looks very closely) I know Ektachrome was red sensitive... What is interesting is that the limiting magnitude on stars is more than adequate compared to my slide, but the loop (red nebulosity) is completely missing.
PS Barnard's loop is not an easy subject, BTW. You will record the Flame and Horsehead first. A very worthwhile summer contest, I suggest, for the learners.
Damn it's been trickier than I thought, but I got it.
Tried just about every setting on the camera, that is with my limited knowledge.
Anyway here's my attempt at a single frame to image barnards loop.
Camera Canon 1100D.
Settings 18mm lens at f/3.5 - auto dark frames and high ISO adjustment off - ISO 6400 - 240 sec exposure.
There's no way I could have captured this with out a tracking mount, so on that score I failed, but it is a single frame. The only adjustments were done in Photoshop.
