Day 1 of Tony's astroimaging adventures

[that_guy]

Hi folks, took some pictures while testing the new guiding. The moon was on full blast so exposures were limited to 1 min :(. Got some decent subs tho and some darks. Recently bought Startools as well so I cheated my way through processing :P.

[that_guy]

anyone know what this black dot is on the right hand of the images? is it a dirty camera sensor or is it on the scope objective? cant seem to find anything on both to be honest and they're on all the pictures ive taken so far. they're a bit more prominent in the eta carina picture if that helps

[billdan]

Looking at the size of that smudge I would say it would be very close to the CCD chip, possibly on the chip cover glass.

This is the formula for working out exactly where it is,

Smudge Distance from CCD chip (mm) = pixel size(microns) x smudge diam (pixels) x focal ratio / 1000

Those test images looks OK Tony, though with Startools I would have expected richer colour on Eta C ( maybe not enough subs). I'm lazy and I use Startools as well and I'm reasonably happy with the program, I get much better results than previous techniques I've tried.

Cheers
Bill

[Mickoid]

I'd say if it appears in the same place of the frame when you check your shots it will be a foreign body on the camera sensor. They (sensors) are susceptible to contamination especially when astrophotgraohy requires the camera being removed from the OTA regularly. They can be very small to the naked eye and the sensor may appear to look clean. I clean my sensor when I see too many of these nasties because there's only so much the flats will do to eradicate them.

[that_guy]

would compressed air canister be ok to clean the sensor? im assuming theres some sort of glass cover protecting it.

[billdan]

Have to be careful with compressed air canisters, as they can sometimes spray condensation out and leave a film behind.

[that_guy]

any suggestions on how i should go about cleaning it without damaging anything?

[Mickoid]

I have cleaned my camera sensors many times but I remember being very nervous the first time I decided to give it a go. You do have to be very gentle and use the correct lens cleaning fluids and wipes to do it safely. Sensor cleaning kits can be purchased online but if you don't feel confident doing it yourself, get it done professionally. Most well known camera stores and specialised camera clinics will do it for you - albeit at a fairly steep price, one reason why I decided to do it myself.

[sil]

Talk about over reactions. You mostly only need a bulb blower to clean sensors, you gently squeeze to bulb to blow air to dislodge specs like this. Turn the camera so the sensor is facing down while doing this and keep it that way until you put a cover on it otherwise dust just settles back down out of the air onto the sensor again, upside down spec dislodge and fall to the ground. Any cheap bulb blower will work available everywhere camera accessories are sold. No "best brands", just buy a half dozen, they are rarely more than a fiver. If you are touching the sensor for cleaning it then you're doing things wrong and more likely to cause lasting problems.

[that_guy]

i gave it a good puff with the bulb blower like you said, that SEEMS to have dislodged the dust, test shots have been clear but shall see next outing aha thanks sil!

[LostInSp_ce]

Nice Tony and the guiding looks good. What's in store for Day 2?

[that_guy]

nothing while its constantly raining and overcast aha. my west and east (and some of north :P) is blocked by trees, my house and neighbours house. so targets are really limited aha. So far, I've been doing your average trifid lagoon, carina and cent a before i had guiding. I might try and get more data for m83. personally, i enjoy galaxies the most. one of the reason i want to get a newt for feint fuzzies.