Frustrated

[Neil McRae]

I am having tracking problems I think.

Using Eq5 Syscan and SW200P + Canon 450D tonight I tried several photos of the M42 Nebula. Power was via a 240v transformer.

I Polar aligned and did 3 star and 2 star alignments during a 3 hour session all reported successful.

Siderial Tracking selected.

I used ISO 1600 and various exposures from 30 to 4 secs.

Scope has been collimated yesterday and perfect even when defocussed on a bright star I had concentric rings.

Used a Bahtinov Mask and had perfect focus on the camera.

Now here is the results I got. Depending on exposure length I had star trails and this reulted in poor "focus" on the nebula.

Any ideas please as this is exactly the same as I had 2 weeks ago which prompted the purchase of a collimator and Bahtinov mask to no great avail. Is this someting to do with the tracking rate of the Synscan i.e. does it only update once per minute or some other number ?

Neil

[rowan46]

hello neil I may be off but the eq5 is at the top of its weight allowance with a 200p on top I am not an imager but I read that most imagers go to half the weight allowance for their mount it could be the weight of the ota thats the problem

[Sarah]

Yes it may be the mount isn't sturdy enough. Can you post an image as that may make it easier for someone to advise on?

How are you taking the images with the DSLR? Are you touching the camera, or are you using a remote shutter release control?

[Neil McRae]

Hi thanks for your replies

I was using a remote to trigger the camera.

2 Images attached one from last night and one from over a week ago.

To me they look like the mount was stationary

Neil

[Panzer]

Wow, is that colour real or photoshopped?? I thought all colour had to be added later but if I can get that from my scope I'm splashing out asap on some AP kit!

Regarding your tracking - I also have a Synscan, and also find it really temperemental. Sometimes it will track for a short while then stop for no reason. I think your problem will probably be the weight of the camera fighting against the motor, causing it to lag. Sounds daft but was there any wind? I find even the slightest breeze can cause the OTA to wobble, and thats without the added weight of a DSLR.

Well done on those pics though, aside from the light pollution and slight blur they're great!

[Neil McRae]

Panzer you might have the answer. I balanced the scope BUT not with camera attached. I will try that the next time I go out. Colour is real. All I did on Photoshop was ENHANCE brightness and contrast and used unsharp mask under FILTER.

The photos as you can see will be better if the "movement" is cured.

Thanks

Neil

[Black Knight]

I used to use a 200P on an EQ5 (I now own an NEQ6). It is possible to to take unguided images with this setup, but it is definitely tricky. Balance is very important, but you will also need really good polar alignment. I used to drift align as well, and was amazed when I did drift align how far out my polar alignment (which was painstakingly setup) was.

[Sarah]

I was going to say your polar alignment may not be accurate enough. Hadn't even considered balance! I agree. Try balancing with camera and then maybe look at your alignment if balancing doesn't help.

Good luck with this. And it is good to see a start with the imaging. Even though my attempts were rubbish, I was so chuffed to see some colour coming through on M42 despite poor alignment and poor focusing! Your attempts look better than mine did!

[Black Knight]

If you don't have an illuminated reticule eyepiece (I don't personally), but have a webcam and a laptop you could try drift aligning with WCS. Polar Alignment - WCS - Fast and accurate polaralignment for astronomical mounts, using a CCD / webcam and drift alignment

I have used this program in the past. The big advantage with WCS is you just need a laptop/webcam combo. If you don't have a webcam, there are techniques around there that will let you drift align with a DSLR. I can't find a link at the moment though ....

[Black Knight]

This is the sort of thing I was thinking of:

CCD Drift Method | AstroPhoto Insight

The article is entitled CCD Drift, but you may be able to use it with a DSLR.

[steppenwolf]

Your image is showing classic star trailing. The mount you have is operating at the edge of its performance envelope with this telescope so you are asking quite a lot of it. However, there are some things you can try to improve matters.

1. Be sure that your polar alignment is smack on

2. Balance the DEC axis first followed by the RA axis BUT once you have slewed to your imaging object, slightly unbalance your RA axis so that the rising side (this will be to the east) is a little heavier. In other words, if the counterbalance weights are rising, then slide them a little down the bar to increase the weight. If the telescope is rising, slide the counterbalance weights a little up the bar to make the telescope slightly heavier. This makes the motor drive remain permanently under a gentle load so that the RA axis doesn't 'teeter' between being driven and free-falling.

3. Ensure that all cables are fastened to the dovetail bar and hang from the centre of the mount placing no load or drag on the RA axis.

4. Take shorter exposures and lots of them

[Neil McRae]

Hi All. All your answers are great especially as my polar alignment was "rough" i.e. with no illuminated reticule I just put polaris in the middle of the reticule and slightly to the 4 o'clock position as that was where the prediction was. Just thought because I was getting "Alignment Successful" I was ok. I will now go and read your other articles as I do have a web cam and will try out all ideas. Thanks again for all your suggestions. I would have been lost without your ideas. I will post a picture or two once I get the time to sort this out.

Neil

Neil