Demonperformer

If yours is anything like mine, getting your SLIK tripod ready for "proper" astro work is going to be quite a challenge. I will follow your progress with interest.

Do you happen to have a link to your videos. Just bought one of these nd it would be good to see it done by someone who "never had an issue".

Thanks.

Hi, Mark, & welcome to SGL. 

I think an SE mount would struggle with a 925.

I wonder if you have anywhere you could house a permanent setup? There are some ingenious suggestions in the observatories board for small secure housings. Permanently polar aligned and ready to go in a few minutes might restore your enthusiasm.

Yes, excellent. I do like monochrome Ha images. 

Looks like your project is coming along nicely, Andy.

Was originally confused by the apparent absence of the lines in the 'off' graph from the 'on' graph ... then I noticed the scale on the Y-axis!!

Stopping down will basically sharpen the image but it remains the same size & resolution.

I'm no expert, but it is all a balancing act between using a small aperture (big f number) and exposure length. So 60s at f2.8 is roughly equivalent to 120s at f4. I will often play around with single subs using a couple of apertures and a couple of sub lengths at the start and see which I think is going to give me the best results. I find that even the act of taking the subs can be an art rather than a science ... maybe this reflects differences in the way I set up as I do not have a permanent setup so have to do it every time. Unless the f4 subs look quite a bit better than the f2.8 subs, I will usually go with f2.8.

5 minutes ago, alcol620 said:

DP do you have yours stopped down?

I run mine at f2.8 or f4.

When you stop down the lens you are only using the central part of the glass. The curvature on the elements is strongest at the edges and is hardest to get "perfect" and tend to be the worst part of the lens (that's a relative term with a manufacturer like Canon). Stop it down and you are only using the "best" bits of the elements within the lens and so overall get a better result.

Checking at the info on the FLO website, it looks as if you are using the correct spacing (no extender for the 1600) - as such I really don't know what is causing the star pattern. Someone else may be able to shed some light on it. In the meantime the first thing I would do is check if you get the same effect when you take astro pics with this lens on your 550D. If you do, it might be a problem with that particular lens. If you don't then the lens is ok and the problem must lie elsewhere.

Canon 55mm lens? Is that the 18-55 standard zoom that comes with canon dslrs? IMO this is not a wonderful lens. For a canon you can do a lot worse than pick up a "nifty fifty" - 50mm f1.8 II - but make sure that you get the Mk II version. I have used this with my 1600 and got some reasonable results.

That said, the way the stars are stretched is almost as if there is insufficient distance to the chip (see attached pic). Presumably you are using the zwo adapter? As you have the filterwheel, I wonder if you are using the "short" adapter (that allows for filterwheel to be added)? If so, you would need an extension to make up the distance if using it without the filterwheel.

Never done it, never heard of it being done, but sounds fascinating. Do keep us informed on how it goes.

Looks promising.

Checked Peak2Valley website and the CCDSPEC is also discontinued. 

Well, yes, but at $1500 per user per year for the standard version, one would want it to be fairly satisfying ...

I like it ... except that it gives me one more reason to fork out for one of these new-fangled printers!

Nice going. I keep thinking about buying one of these beasts. Currently trying to learn sketchup - no point spending out on a printer before I can produce the templates for what I need!

Not sure, but my guess would be that it is something to do with the central obstruction of the mak (loss of light grasp).

Also, how far apart are your alignment points? Slight errors on close alignment points result in magnified errors as you move further away.

Alignment on my SE mount got a lot better when (1) I started using a reticle eyepiece, and (2) I started using points that were significantly different in both alt and az.

I could do with something like that for my 8" sct when I'm trying to get it onto the EQ6 mount.

New filter ... quite excited to see how they perform in the field (or garden ) ...

I had never used mine, but wanted to check it worked before selling it. Of course, I couldn't find the manual that came with it so went looking on the Internet and found this ... eventually. 

Granted this might be of limited interest, but I had a major problem trying to find this this morning as Skywatcher seem to have decided anyone still using one of these can fend for themselves and have removed it from their website. So, in case anyone else is looking - and in case the site I found it on decides to follow SW's example - I am uploading a copy of the SW syntrek manual here so one will always be available.

Syntrek manual.pdf

You had me at 'easier to make'!

HI, Lorenzo, & welcome to SGL.

Love the idea of plugging wife adapter into the mount. Ain't autocorrect great.