Messier 13 - first attempt at imaging

Just had a try at imaging M13. I am using a Celestron 8" telescope with my Canon 50D. I am very new to all this and I have to say I am finding it really difficult to get images that I am even half satisfied with. No doubt practice will get me there in the end!

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What type mount are you using ? If you use a go-to mount are you using any type of guider mechanism ?? However being your first try i think you have done very well . Lacks any color tho , did you change to greyscale ?

I have the Celestron Nexstar 8SE which has a goto mount. I have the wedge which allows me to set up to track equatorially - if that is the right expression. Is this kind of mount always going to prove difficult to get decent images?

And yes, I did change to greyscale.

Hey mlc, another Hampshire bumpkin I see!

What were the image settings of your shot? ISO, exposure? You've got the brighter stars in the clustuer, but not that many of the dimmer ones, so I'm assuming this was a fairly short exposure or your ISO was very low? There appears to be a bit of trailing too, so it seems your mount wasn't too accurately polar aligned? I'm not familiar with the wedge systems, but I think as long as you get it set up right you should be able to take longer exposures and improve on your images/reduce the trailing.

But yes, practice makes better. My first year worth of images were never even one-tenth decent in my eyes, but it's still fun all the same.

Did you know there is a Hampshire group here https://photography-on-the.net/forum/showthre​ad.php?t=679197

If thats your first attempt its one hell of a lot better than mine!

I used an 8" Meade LX200 for a couple of years and always struggled to get it properly aligned and balanced. Lifting it up onto the wedge always led to a heart stopping moment until it was bolted down.

Am I right in assuming that is a single frame? If so then Deep Sky Stacker is your friend. Take more shorter frames and add them together in DSS. Make sure you have decent balance though I always found a little forward bias helped. Too much though was disastrous. Finally make sure everything is screwed down tight.

Thanks so much guys for the comments advice etc.

Adrena1in the settings were ISO 1600, 60secs. I think you are right about the polar alignment being a little out - I have only had the mount a few days - and the telescope a little longer so this is all very new and I expect as I do it more often I will improve. I guess the very fact that it is so challenging to get everything to come right together is part of the fascination of this hobby!

Chris, you are right about it being just one shot. I did take quite a few but the quality was very variable. Still there were a few I thought might stack so I tried using DSS. Unfortunately with the threshold set at 10% DSS stated it was unable to detect any stars. As I reduced the threshold this continued down to 3% where it detected around 10 and at 2% (lowest setting) it detected loads. I tried running at 3% and it stated that it could only stack one image. I was using the raw files directly and I do wonder if I may get a better result if I convert to jpg or tif first. I will give that a go.

Another area I find problematic is focus. The focus for viewing with the eye is different from that required for the camera. I find it very difficult to focus on faint/small objects using liveview/viewfinder. My solution so far is that I have made a makeshift dial that I have attached to the focus knob on the scope. I can then focus on something bright (eg Jupiter) and make a note of the dial reading. Then back to find and centre the desired object focused for the eye rather than the camera. Then turn the knob back to the focus point for the camera using the dial, fix on the camera and were in business. Am I over complicating this? It seems to work, more or less!

Yep focussing is absolutely key to the whole hobby. With a 50D you could try live view onto a laptop screen or go for a trial of Nebulosity. Its not free software but has one of the best frame and focus routines I have seen for getting critical focus using a DSLR.

(I woud not take .jpg's into DSS. They will be no better)

Re. focussing, make yourself a Bahtinov Mask -> http://www.focus-mask.com/Free_Template​s.html

Or ask nicely and I'll make one for you...I've made several, and though I've not tried any yet, (I'll ask the chap I gave an 8" mask to how it's doing), I found the process of making them quite relaxing. Girlfriend would sit there and sew, I would sit there and cut out Bahtinov Masks from a piece of black plastic sheet that I bought a long time ago to make some baffles for my telescope, but never did.

And cheers for that link Artyman.

Thanks for the lead on Nebulosity Chris - I will check that out. I will need to work out how to get round the fact that my laptop battery is knackered and lasts less than 60mins so not currently practical to have the laptop close to the scope. I guess a replacement battery is the obvious option! Or a very long extension lead - I tend to use the scope in the field behind my garden so quite a way away from the nearest electricity supply!

I made myself a Bahtinov mask a week or so ago. I cut it from stiff card. Unfortunately with the heavy dew we have had in recent nights this was not just the best material to have used! It does work though. Oddly it works through the camera eyepiece but not in live view - the diffraction lines are simply not visible in live view. Not really worked out why this should be!