Well its a start, M109, M101, M81/82

[Chris]

A couple of very short sub exposure Ursa Major Galaxies, I'm sure I'll look back and laugh M101 had 67 x 15 seconds the other week, and last night I gave M109 a shot with 139 x20 seconds plus 20 darks (and the moon getting in on the act) all stacked in DSS and tweeked in Photo Pro. Still with oval stars after about 70 minutes tweeking my Polar alignment and a bit of drifting he he..

[stan26]

Nothing wrong with them Chris, as you say its a start and we all have to start somewhere! I still have on my hard drive my first set of subs I took of M101 and they aren't as good as your effort! I haven't gone back to them since. I reckon you can easily squeeze 30-40 sec subs out of your EQ5. Did you do the camera drift align method? its a lot quicker than using the cross hair method. Also I guess you are balancing the scope correctly, i.e heavy side on east..? this will all help with longer subs and more detail in return. I found that with the M33 galaxy the last faint one I had a go at I needed about 2hrs of data just to get any structure and that was with extreme stretching in PS!

Regards

Stan:cool:

[Chris]

Hey Stan, thanks for your comments yeah I have my counterweight down the bar to take up the slack on the gears as you kindly recommended and I think I'm keeping more subs because of it, but just to make sure I've got you right when I'm behind the scope it will rotate up on my right side with the Earth rotation? I've kind of made up my own version of drift allignment where I initially polar allign by eye thorugh the polar scope then find my target take a 60 sec exposure look which direction the stars are trailing then adjust the scope east or west and repeat intill the image settles on one axis, then I repeat with the other axis with the alt/az bolts untill I've got the stars looking round on the 60 sec sub, the problem is that this changes from one image to the next? I think like you say from our last conversation the mount needs a rudy good service, or better still upgrade

How you getting on with you guiding, I'm well impressed with what you have achieved with your setup so far!

chris

[Quatermass]

You did better then me last night Chris I tryed for ages to find M101 again and gave up defeated at 1pm sigh its a swine to find M51 is far easier. Nice couple of images its good to capture these faint fuzzys gives me quite a thrill when I get a new one on my hit list.

[Tinker1947]

Gotta laugh i tried for quiet a while to find M51 and gave up, but M101 last time i tried popped up very quick...

[Quatermass]

I reckon they move slightly to one side to confuse us

Sent from my GT-S5670 using Tapatalk

[stan26]

Hey Stan, thanks for your comments yeah I have my counterweight down the bar to take up the slack on the gears as you kindly recommended and I think I'm keeping more subs because of it, but just to make sure I've got you right when I'm behind the scope it will rotate up on my right side with the Earth rotation? I've kind of made up my own version of drift allignment where I initially polar allign by eye thorugh the polar scope then find my target take a 60 sec exposure look which direction the stars are trailing then adjust the scope east or west and repeat intill the image settles on one axis, then I repeat with the other axis with the alt/az bolts untill I've got the stars looking round on the 60 sec sub, the problem is that this changes from one image to the next? I think like you say from our last conversation the mount needs a rudy good service, or better still upgrade

How you getting on with you guiding, I'm well impressed with what you have achieved with your setup so far!

chris

Sounds like bad periodic error, but it could still be your polar alignment. Just to confirm Chris - You need the balance along your RA to be slightly heavier on the EAST side. If your standing facing north (polaris) with the mount in front of you, the heavy side will need be on your right, because the sky rotation moves East to West and you will always want the side that's being pulled "UP" the heaviest which will always be the EAST side. It doesn't matter if its your scope or your counter weight on that side just make sure its weigh bias to the east.

If I'm honest I wouldn't of thought your way of polar aligning is that effective especially because you could be led down the wrong path by periodic error by doing it your way. You need to exagerate the star trailing more to get a good alignment. The way you are doing it will only show minimal drift error because your mount is already 95% correct and following the star if you get what I mean. You don't want to chase the star to align the mount accurately, you need to measure declination drift over a greater distance.

To drift align, set up and roughly align as per norm. Then find a star due south (or north if you can't see south) fairly low on the horizon and get it centred on the camera, switch on your RA drive to track it. Next is the special trick to speed up time to measure the drift quickly. Set your hand controllers slew rate to fastest setting 8x..? Set your camera to take say a 1min exposure. Start the exposure and leave everything for 5seconds, after 5secs have gone by press and hold the WEST RA button for 25secs. As soon as it hits 30secs exposure time hit and hold the EAST RA button untill the full 1min exposure is done. Take a look on your dslr screen and see where the star has drifted (north or south) and adjust the mount accordingly. Once there's no drift on the southern star do the same in the West. This is a very quick and accurate method to drift align. It done wonders for me!

Get yourself a pier, I got fed up of aligning all the time.

Stan:)

[Chris]

Hi Stan thanks for your help I'm pleased to say that I did have it right with regards to the balance of my scope with the counter weight rising up on my right (East) so it loads the gears with the Earth's rotation like you say. I understand what you mean about "chasing the stars" and my weird at the time logic was that I had by chance got my alt/az adjustment spot on as the star trails were complety horizontal on my 60 second subs with the scope levelled, so I thought to my self I wonder if I can fluke the other axis, which off course I didn't but kept on making east and west adjustments because I was chasing the dream of getting it spot on using my almost guessing method I understand how to do it properly honest . In fact I'm out now imaging M51 and I did start out as I did before with my slightly mad method, and I got to the point where I thought if the next adjustment does not work I will drift align properly, but then the next adjustment was almost spot on so I made a couple more very very small adjustments and got round stars on a 60 sec sub, I did get a buzz from this I am playing it safe though as I know that I will need to do a major crop with m51 and any trailing with be magnified, so I'm sticking to 15-30 sec subs, but I'm pleased with 30 seconds! I am so going to mark the position of my tripod legs on the paving so I can have less faffing in future. After all this I can definately see why you opted for a pier thanks for your help and I'll let you know how the M51 goes. Are you out tonight, its so clear! but cold!

Regards

Chris

[Quatermass]

I would love to have pier because polar alignment every time is a pain but thats not an option because of the trees around me. Cleaning my EQ5 mount did help a little but often I find just moving the weights a little or simply pressing the control pad forward then back a little cures the star trailing. Sometimes I just think its time to call it a night and go to bed lol. Actually 3 concrete blocks with a small hole chisled out for your telescope legs could be a good answer just find a good spot in the garden put the 3 blocks down and chisel out the little holes so the legs fit them nicely and then level it all out. Next night put the legs back where they were and your pretty much there. mmm where is my chisel?

[Zul]

Nice.