Help with workflow

[UKJay1971]

After another unsuccessful night (well, it was successful in some ways, but not in terms of imaging), I realise I am not confident I have a good workflow. Here is what I do now, with the problems I have:

DAYLIGHT

1. Align my mount using a compass (true north, not magnetic) and a digital spirit level for latitude angle. Ensure that my mount base is level.

2. Set up rest of equipment and ensure it all connects

DARK

3. I fake an alignment on my GOTO mount to allow for the laptop to make adjustments via serial cable

4. Fire up PHD2 and polar drift align - I have an issue with this as I am not sure how accurate my Celestron GT mount is in terms of azimuth adjustment because I find it incredibly difficult to get near horizontal alignment in PHD. I typically get within 0.5 - 1 arc seconds of error but any other adjustments seem to send the error off in the other direction

5. Once drift aligning then I attempt 2 or 3 star aligning on GOTO - I try and use my camera with a cross hair in the software but is this wise, or do people align by eye then add their camera? (My alignment failed last night so I guess I might have answered by own question)

6. Use Bahtinov mask to find focus (again, I have some problems doing this on my camera as I find it difficult to see the diffraction spikes on my laptop screen)

7. Use plate solving to try and ensure that mount is well aligned

8. Try and image

9. By this time my PHD is starting to show wilder deviations on the graph so I get fed up and pack it up.

I appreciate I am being really inefficient here and I'd really value input to help me streamline as I am spending over an hour getting set up and I am sure I can do it quicker.

[Anne S]

How are you guiding? The latest version of Sharpcap has a polar alignment routing that uses a finderscope to guide with. That would be much quicker than drift alignment. It's free. You use a modified webcam, something like a GPCam or other guide camera to take an image, Sharpcap platesolve. You then rotate the mount manually and take another which is platesolved. Sharpcap then gives instructions how to adjust the mount. It takes away some of the adro, particularly if you have any difficulties finding suitable stars to drift align with. 

There's also a method of polar aligning using PHD2, can't remember how but it's something to do with disabling Dec guiding and watching the Dec line in the trap and adjusting the mount controls until the line stays in the middle. You don't need to be spot on in Dec as that keeps the Dec motor adjustments in the same direction and prevents bouncing/backlash issues.

Do do you level your mount with a spirit level before starting? I generally find azimuth is easier to get right. You need to make sure you loosen one screw before you tighten the other. Same in altitude. Can't remember how precise the adjustments are as it's a long time since I had a CG5! I now have an eq6 which is tricky to do the altitude adjustment and the scale is 3 degrees off!

if you're platesolving, do you need to do a 2 or 3 star align. I slew to a bright star near where I want to image, centre using the red dot (which should be aligned with the scope in daylight), by now the star should be on the camera. Focus. Centre on the chip, platesolve. Slew to my target and place where I want it.

Start guiding. Focus main camera, start imaging.

I'm lucky in that I have a fixed setup at home but I do image at Kelling and use the above method to set up, with the only exception that I use a Polemaster to do the polar alignment.

i hope that helps a little.

Anne

[wimvb]

What do the stars in your single subs look like? You may be missing good images while trying to chase a perfect alignment.

Polar alignment doesn't have to be spot on.

Also, if you use plate solving, you don't need (accurate) goto. The plate solve takes the place of goto alignment.

My method to focus using a B-mask, is to take short exposures at high ISO and adjust focus inbetween. But then, my camera's live view is pretty useless, and the camera can't be controlled by computer (usb).

[iapa]

My main issues with PHD2 going way off tracking were down to wrong focal length of guidescope and wrong camera spec.

 

I also use platesolving to centre targets and capture s/w with a mask to get focus..