M13 with Nikon D40

[geppetto]

Really pleased with this one.

M13 Nikon D40 prime focus 200mm F5 reflector.

Single frame 75 seconds

[barkis]

You've every right to be pleased Phil. For an exposure as short as a minute plus some, it is a great result. It is this method of imaging that gives me a lot of pleasure, because it is relatively uncomplicated, and produces very acceptable pictures. I don't want to come across as flippant here Phil. I realize the task is not as simple as I make it sound. I like it a lot.

Ron.

[geppetto]

Thanks Ron

Appreciate the encouragement

[Cloudgazer]

Yep thats a nice M13.. and only a single 75 sec frame :shock:

Scott

P.S. Is there a faint fuzzy in the bottom right part of the image?

[SteelRat]

Do like that Phil. S'a sweet globbie 8)

[Kai]

Thats a nice picture Phil.

Was that taken on the pier ? if so you have got the tracking sorted.

[richard42]

that is a great image! love m13 and very sharp focus!

[Kaptain Klevtsov]

Super M13 Phil. Tracking is spot on and there's no wobble so your pier is working perfectly.

I notice it looks a little B&W, is that converted to get rid of colour casts, or did you use a B&W mode on the camera?

Captain Chaos

[Kain]

Very nice Phil!

I have no idea when it comes to the technical side of imaging, but I know an image that I like when I see them, and this is just that!

Kain

[geppetto]

Cheers guys

Yes it was from the pier (very pleased with it, should have built one a year ago) 8)

Well spotted CC, yes I turned the colour off, too much orange sky

Gonna have to invest in a 2" LP filter at some point to fit my "T" adaptor setup.

This widefield stuff is going to be "my thing" I reckon, so need to tool up as they say

Got M57, 81, Leo triplet and quite a few others for the album.

Bit like fishing in a barrel last night

[moondog]

Phil, that's a fine image of M13 - especially for a single frame.

Good tracking and tight, round stars.

8)

MD

[geppetto]

Posted a small pre tweaked version of the M13 shot to show the LP problem.

What I am very pleased about is that the D40 is proving to be a credible camera

for astro work.

This shot was at ISO 800 and the noise levels were quite acceptable.

Gonna have some fun these summer nights 8)

Question is, what's going to be the best LP filter for this orange muck?

Have a Baader moon/skyglow one which works very well but it's 1.25".

Suppose a 2" one of those might suit the job.

[MartinB]

Lovely image Philip. What I really like is that the core isn't burnt out at all but you have brought out lots of the peripheral stars. Nice work on the processing and as KK says tracking looks sweet.

Don't get an LP filter to correct the orange glow if you are imaging in colour. You will just get blue/green colour cast. The sky glow will limit your overall exposure time since it will start to excessively brighten the sky. However it is very easy to process out the orange colour cast. Just go into levels and select the individual channels seperately. Move the black point to the start of the steep rise in the histogram on the left hand edge. Do this for each colour channel and you are just about there. You need to repeat the process if you move the white point over to the left or if you do a curves stretch.

I edited your orange image using elements V 2 so no curves trickery!! There was a little vignetting at the end so I lassooed the affected area, set a feather of 40 and adjusted the black point for the individual colour channels in the selected area.

You could spend the money you save on not buying an LP filter on Noel Carboni's actions for photoshop elements http://actions.home.att.net/Astronomy_Tools_For_Elements.html

[geppetto]

Thanks for the advice Martin, much appreciated. 8)

I posted the origional full image for tweaking by anybody who wants a go

http://stargazerslounge.co.uk/index.php?topic=13543.msg139914#msg139914

[jcm]

Question is, what's going to be the best LP filter for this orange muck?

Have a Baader moon/skyglow one which works very well but it's 1.25".

Suppose a 2" one of those might suit the job.

I had a long chat about this with Bern ( Modern Astronomy). At the moment I am just using a neodymium filter which does not introduce much extra colour. ( well up to a maximum of 8min at 800 iso). I am going to try the Astronomik CLS filter , which , reading other peoples accounts seems to do a good job. I will let people know how I get on.

John

PS Excellent image for a single frame.

[Caz]

That Nikon of yours is doing you proud Phil, great capture...

Caz

[geppetto]

Thanks Caz