alcol620

Hi folks, feedback required on problems with star trailing on my SSA set up. Trying to get the set up to work so I can get out into the country dark sites. I have an ASI1600MC mounted on a TS Optics 60mm with flattener (focal length 260mm). I have taken time to polar align, checked that it does a full rotation in 24 hours but anything over about 30 sec subs and I get star trailing. Balancing is not easy and the camera and scope looks quite weighty for what is a rather flimsy set up. Any feedback welcome on how to get longer subs that others seem to achieve.

Thanks guys, wasted a couple of hours this morning trying to attach the crescent nebula without success then found this thread and hey presto all solved with the update. Thanks again

Thanks for your help Robin

Robin I did notice when imaging last night that most of the corrections on the PHD graph were RA and only occasional DEC so this bares out what you say. Should I attempt to measure PE and get the software to take it into account or just accept that it is there and simply let PHD guiding take it out? I read somewhere that trying to take it out sometimes confuses PHD. Alec

Thanks Robin What would the best way of checking this out? Alec

Hi Set up last night and checked PA and it was how it was left from the previous night at less than 1 minute error. I have attached a screen shot (Sharpcaps Snapshot was greyed out and I couldn't use). Following this check I then took and image without guiding and got the attached image with star trails. I turned RA and the stars appeared to turn around the NCP. I forgot to check the setting against PHD drift alignment. The only saving grace is that PHD guiding gets rid of the star trailing. All a mystery. Is there anything I could be doing wrong? Settings etc. How does Sharpcap pick up location, time etc (GMT or BST) Any comments welcome

There is a slider at the bottom of the screen.

Thanks Robin I will try what you suggest next time out and report back. Regards Alec

Hi Robin Thanks for that. Obviously with the mount being mounted on a Rigel Pulsar pier, movement from this should be minimal or non existent. Are there any other factors like data that I have to enter that I might have got wrong. I was disappointed as Sharpcap Polar align seemed to be working fine, Finding stars, giving me adjustment distances etc etc. Regards Alec

Hi folks I thought I would take my time last night and check polar alignment using the sharpcap software. It all seemed to go to plan, after a fair number of adjustments to the up/down/left/right the software indicated that I was within a few seconds on being spot on. I have a ED80 scope, AZEQ6 mount on a Pulsar pier. However, when I did a check on star trailing, ie running a 120s sub with no guiding, PHD not running I get quite long star trails. I have been under the impression that if I get polar alignment spot on, star trails would be a thing of the past, especially those of only 120s?? Ideas welcome, am I doing something wrong?

The ASI120 would have been an excellent guide scope.

Having been using PHD guiding for well over 12 months, believe it or not, I have only just noticed something odd about the setting (probably down to me, but I would like to know what is going on). I have always had the Global setting in the Brain which has "Dither in RA only" ticked. However, when I look at the graph when PHD is guiding and dithering occurs, the spike is always to the DEC trace. Anyone have any idea why this is happening?

Suggest you calibrate in the area you are going to image in. If you move to another area of the sky and guiding is Ok - carry on. If not recalibrate. It only takes a few minutes.

Hi Robin Similar experience to Nebula from Madrid. I PA'd the other night using SharpCap and the software said I was within 10", as I said I ran a 30 minute sub and found little in the way of star trails. Tonight I ran PHD2 drift alignment and had and error of 2.9' (25px) for the AZ adjustment and about 4' (52px) for the Alt adjustment. I am on a pier with and ED80 scope with Atik 383 camera, so I don't think there is any problems with flexing. Any ideas? Thanks Alec

Presumably getting a bit heavy for the Skywatcher Star Adventurer, with an imaging DSLR also on the rig??

Hi Robin Do you have any suggestions of how this software might be used to polar align a Skywatcher Star Adventurer? Presumably you would need a light weight guide camera and guide scope? Or is there another way? Thanks for your help Alec

Hi Robin I seem to have had better luck a second time and could see all the info on the screen. Played around with the Alt and Az and got the Polar Align Error down to about 10". Took a 30 minute image with no noticeable star trailing. Will check against PHD polar alignment in due course. Provided my alignment is as accurate as the software says, then it is an excellent way of getting accurate polar alignment. Many thanks for your efforts. Alec

I have a fixed pier and have been taking 10 minute subs with no visible star trailing Downloaded the software and tried out this evening. Followed the process and the program came up with the following results.Polar Align Error 00 06' 50" and told me to move the Polar Axis Right 00:05:36 and Up 00:03:55 however it didn't show anything else on the laptop screen to show where to make the moves to. Any ideas? Thanks for your help

Suggest you get Ascom EQmod running first.

Nice bit of kit, just waiting for a voltage controller from China so that I can make a dew shield heater for the Canon 550d. Then I'm set to leave it running in the garden. With the camera controlled with APT software.

Ballhead make sit easier to move the camera/scope position without moving everything else. The WO Zenithstar 71 may be pushing it a bit without a substantial tripod?

Hi folks Had a couple of quick sessions with the SSA with a Canon 550d mounted on it. Tried a 50 mm fixed lens and a 18/55 mm zoom lens. First problem is dew, not too much dampness required before the lens fogs up, in the process of making up a small dew heater to go over the lens. The wide field images I obtained using 120 sec iso 800 settings give reasons for optimism once I get a bit more practice. My reason for posting was to get views on the partly processed image shown. I assume the artefact on the two bright stars (deneb and vega) are caused by reflections in the lens somewhere? The 50mm lens images are fine, the image shown is from the 18mm/55mm lens. Would anybody like to comment? Also is there a Pixinsight technique to remove the artefact? Thanks Alec

Just had a go with the SSA and found, as Dave did, that there was no need to use the illuminator. Simply shine a small torch over the end of the polarscope to see the circle and marking to align Polaris.

Thanks GeoC very helpful Regards Alec

HI GeoC What tripod did you use? Thanks Alec