Abysmal M101

[greenkat]

Ok, someone help me out here

Using a Meade DSI-C 1 on Orion Optics 6" reflector, .5 focal reducer, light pollution filter, using envisage set on drizzle, about 40 20sec exposures, this is what i got :scratch:

Next image is the best I could get after messing with levels, curves ext in photoshop

Now, I can see M101 is there, correct me if im seeing things, so, why does it look so Rubbish

[beamer3.6m]

I think you out of focus for a start. Your stars look very bloaty.

The image is very bright, Why so blue, did you image this early on in the evening?

[greenkat]

Hi Beamer

The blue is caused by the light pollution filter, it seems to turn everything blue, even when using it visualy, though you do seem to lose a magnitude or six , hold it up to a streetlamp and it just dissapears .

As for focus, I thought I had pretty good focus as I tried to get the stars as small as possible. Isnt the bloating effect due to overexposure of individual stars ?

I did get quite a good image of Duphe , I'll try posting it tonight.

Forgot to mention though, these were taken through a window

[Psychobilly]

I have found the DSI's to be tricky beasts so mine get used as guidecams now.

There is a much improved focus aid in the latest vesion of envisage which you can download of the web...

Draw a box around a star and you get a 3d surface plot of the intensity which you can use to focus for the smallest top and steepest sides...which occurs at best focus..

Billy...

[Ant]

I would also forget the LPR filter. I doubt you'll need it for 20 second shots.

I would try to nail focus as beamer mentioned, then increase the exposure to 30 seconds and DO NOT include the LPR filter.

This will let more light through. Also allow 10 seconds between frames if possible to give the chip time to cool. I usually allow between 30 seconds and a minute between frames - it does help with noise.

Also did you take any dark frames? They are also extremely important to the look of the final image.

Good luck - you're well andtrulyon the slippery slope!

Ant

[thing]

I'm far from being an expert but taking images through a window is a non starter, the glass will throw up all sorts of aberrations. Plus I don't think that 20 secs is going to give you enough data, you ought to be going for at least 1 minute subs.

[Vega]

You could of got away with saying "My first ever daytime DSO!!!" , I would have believed you .

Matt

[Ant]

Didn't notice the window bit...

That's going to cause you no end of issues, the glass in the window isn't optically very good, if the window was closed. If open then the difference in heat between indoors and out doors will be a nightmare.

Go outside - things will improve no end!

Ant

[beamer3.6m]

Good first effort though.

I'm afraid this hobby is all about the practice.

[greenkat]

Thanks for the replies guys,

Billy, I do have latest version on envisage with the 3d focus window, but i'll keep working on the focus.

Ant, no LPR? , lol, anything over ten seconds turns out like tango man from here I have seen pics stating lpr used, and the pics still seem to have the star colours, mine turns everything blue. am I using the wrong type of LPR filter? no idea what make mine is, its just one I bought years ago.

Vega, lol, the pics were taken after midnight, so technicaly I could say morning shots

Beamer, I wish it was my first attempt lol

[thing]

I don't know if you are stacking in DSS but when you've stacked you are left with the stacked image and the colour histogram at bottom left. If you are getting loads of light pollution then the red curve will be far over to the right compared to the green and blue. Use the sliders to bring the red curve over to the green and blue curves and then align them all up so they are on top of each other. This will shift the vast part of your LP.