m57 ( uk )

[little col]

first one is on the st80 refractor

second is on the 130pm reflector
both 5 x 30secs iso1600 dark subtracted
http://i124.photobucket.com/albums/p...st/M57WIDE.jpg
http://i124.photobucket.com/albums/p...st/m57big2.jpg

[Astroman (Andrew Wall)]

WOW better than my efforts from the other night, All I got was a blob LOL... Nicely done.

[davidpretorius]

geez, lord of the rings

[Ric]

Very nice Col, lovely sharp images.

Well done

[Dr Nick (Nick)]

Nice, colour is a bit off though

[Bassnut (Fred)]

Not really a wide field object, but you sure got it, on an ST80??, sheesh, your game ;-).

[5ash (Philip)]

I liked the second one the best.Ive taken pics of this and im sure theres more colour. also are they the wrong way round?the one with the refractor has diffraction spikes on the bright stars and the one through the reflector has none.
philip

[jase (Jason)]

This is a tough target and best suited for focal lengths upward of 2500mm.
Still a fine effort. Well done.

[little col]

thanks for all your comments
there may well be more colour in this image to tease out but i havn't got the hang of processing yet , so much to learn in so little time

[Ingo]

Looks pretty good, I've always liked mini, sharp, DSO's

[little col]

Originally Posted by jase

This is a tough target and best suited for focal lengths upward of 2500mm.
Still a fine effort. Well done.

thats interesting jase , how do you work out the best focal length per dso if i may ask , is there a formular?

[jase (Jason)]

Originally Posted by little col

thats interesting jase , how do you work out the best focal length per dso if i may ask , is there a formular?

Planetarium software (TheSky6 Pro) with CCD FOV indicators enabled is what I usually use. If you know your telescope/camera FOV combination and the object size in arcsecs you can pretty much work out how its going to fill the frame.

Where it gets tricky is choosing suitable framing of an object or objects in the FOV. Compositing is important from an aesthetics perspective and is often over looked. Simply taking "mindless" images is easy, but making it interesting or unusual is the challenge.

[little col]

thanks jase that all makes sense , i use starrynight so i know there is a section to actually get your e.p field of view into the settings so all i need to work out is the combination of the 300d sensor and the two scopes i have to give me an accurate fov to frame my targets with , it may sound silly but how do your work out this combination?
sorry for all the questions its just that i would like to get this part right before going any further if that makes sense

[jase (Jason)]

Col, I'm not going to reinvent the wheel, check this site out if you want to research some formulas - http://sunra.lbl.gov/~vhoette/Explorations/OpticalPowers/9b-fieldofview-s.html
There are plenty of other sites on the net too.

Or

If you want to cut to the chase, download Mr. Wodaski's CCD calc program - http://www.newastro.com/newastro/boo...camera_app.asp

Hope this helps.

[little col]

thanks very much jase this will help me so much
hopefully i will be able to hunt down some nice good size northern dso's to share with everybody