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Daveskywill
13-04-2014, 08:02 AM
Hi everyone:

This is David Williams again. And I just had received a TeleVue Powermate 2" 4x barlow. And decided to try it out on Mars plus using my Antares 2" 1.6x barlow using my ST-2000XCM CCD camera.

Also I noticed that my mount or wedge was extremely shakey and unstable; because using a laser mounted on the front of the scope, and aimed at the
obs wall only 5 feet away the laser would bounce up and down about 3/16"

to 1/4" max amplitude then stable out. This was a problem. So I followed
about all the stabling advice on making a Meade Superwedge beefed up and
blessed. And now the max amplitude is about cut in half. But that's still
not so adicut. I'm still perfecting again my polar alignment.

PS: I do have a Nikon D800 DSLR, but surmise my mag of Mars will probably be
as large looking with it using those 2 barlows plus my Meade 1.25" 2x triplet compared to this pic taken with the ST-2000XCM as described above.

PPS: is Mars blurriness due to the mount shaked? It was a 1/2 sec exposure. 1x1 binning an autodark was taken.

Or was it a tad bit out of focus. I just guesstimated using the peak focus
numbers.

Thanks

LightningNZ
13-04-2014, 11:17 AM
The intensity looks spherical - it's well out of focus.

Astro_Bot
13-04-2014, 11:37 AM
That exposure is way too long. With a DSLR, I've been using 1/100sec and ISO400.

With an exposure that long (1/2sec), it won't matter whether you're focussed or on a stable mount or not (though those may well other problems), since Mars will move so much during the exposure that it'll be blurred (and hopelessly overexposed) anyway.

Best to focus on a star first then move/slew to Mars.