First decent attempt at M51

[ubertank]

So after initially taking four or five 30 second exposures at ISO800, I went out the other night and took around 20 at ISO1600 for 90secs. The tracking held up reasonably well considering it was unguided and after a bit of processing this is my current best image.

I have so, so much work to do to learn how to process correctly, but I'm quite pleased with the outcome so far. The stars (more notably the large one) are clearly distorted and I've had a real tough time removing the blue tint from my CLS filter. I'm really finding it hard to get a more "true" colour and get rid of the blue tint without making it green or yellow. Any advice here would be welcomes.

So here it is anyway. 20 x 90 sec exposures on Canon 1100D with Astonomik CLS filter, through ED80 on NEQ6 pro. No flats or darks yet. Mostly edited through Startools, then screenshotted and a JPEG loaded into PS (haven't yet paid for Startools) Between that, saving as a JPEG again and then uploading to photobucket, there's a fair bit of quality lost along the way here (excuses ).

Would love feedback and advice.

[mart rich]

I think that is very good. I am just struggluing with M51 myself and hope to post an image soon, so I have a great deal of symapthy for the effort and learning curve!

Keep up the good work.

Out of interest what is your PA routine? I think I have managed to get 90s exposures that are worthwhile (yet to be processed), but I need to try and improve my PA by adding drift alignment, but that is yet another step to learn and is only worthwhile if I can leave the scope out for a few nights to get the benefit of the setup time. Changing the mount Alt bolts to the Astro Development upgrades has made PA a lot easier - the old ones had bent.

Martin

[ubertank]

Hey Martin,

Thanks for the comment. I think that I may have chosen a relatively hard target when it comes to getting the most out of the processing but M51 to me has always been one of the most beautiful objects in the sky so was excited to get right on it.

As far as my PA routine is concerned. I firstly make sure the mount is perfectly leveled and aim it north using a compass. Add the head which is already set to the right latitude for the dark site I use. Then if it's a bit dark I have to hold a red light to the top of the polar scope whilst awkwardly rotating Ursa Major to the angle it is pointing in the sky. I then adjust the bolts as required to place Polaris in the right spot. I then add the scope and weights and check the alignment is still correct with the increased weight, but this is never really a problem as an neq6 laughs in the face of an ED80 and a single weight.

That's basically it mate. I haven't performed drift alignment at all yet.

[mart rich]

I was absolutely thrilled to see M51 pop up in a test 30s exposure for the first time. No chance of seeing it through the eyepiece in my ED80 - it is well worth the effort with the camera.

Try getting some darks if you can, bias are quite easy too but the flats can be a pain.

I usually set up in the back garden, which is easier as I have marks on the patio now for the tripod feet, but the downside is the light pollution, although its not the worst in the country!

So I know the mount is roughly aligned and level. I then read off the transit time from the handset and rotate the clock on the polarscope to read the correct time (basically the same as aligning Ursa Major, maybe a bit more accurate) - should be easy but the clock is loose on the EQ5 so requires some contortion and crossed fingers. And yes then it is back to holding up the red light while adjusting the bolts to get Polaris in the circle, as you do. I tend to do all of that with the scope and weights on, not too bad and only have to do it once.

I have 40 x 90s plus darks, flats and bias of M51 waiting for my attention in Nebulosity (don't have PS). Hope to get round to it and post later this week.

Martin

[Scott]

I was struggling with the blueish stars too and someone on another forum suggested setting the white point to the centre of the galaxy. I also lightened the background sky as well to bring out more of the nebulosity. I don't know if any of this is the right way to do it but it improved my image .

M51 crop2 v4 JPG by Scott Prideaux 1961, on Flickr

[Astrosurf]

In PS I line up the graph peaks in the red, green and blue channels in the histogram. Have you tried that?

It's a lovely pic nonetheless!

Alexxx

[Twisted Lip]

Great pic, interestingly I was photographing the moon last night with the CLS Clip Filter in for the first time and noticed it was a very blue moon (no Manchester City jokes please Haven't done any post processing but I put it down to the filter.

If you can't see M51 through the your ED80 are you trusting your alignment to put it in the centre of the screen of are you taking a few shots and centring subsequently?

[mart rich]

When I tried I managed to get it centred after aligning on Mizar. That was a big relief as I didnt fancy too much faffing waiting for a 30s exposure each time to see if I had guessed the movement direction correctly!

I am not normally too precious about getting the target centred in the image, as long as it is reasonable.

Martin

[Twisted Lip]

Cheers Martin, annoyingly I do exactly that (take pictures for 30secs to see if I'm in the right place!) and its a complete pain. I tried a couple of M81/82 last night but was really struggling (and tbh the moon was too bright)

Will

[Scott]

if you crank the iso up to 6400 then 5 or 10 sec subs should show enough detail to frame your object. just don't forget to reset your iso . I've never done that........honest

[Guest]

So after initially taking four or five 30 second exposures at ISO800, I went out the other night and took around 20 at ISO1600 for 90secs. The tracking held up reasonably well considering it was unguided and after a bit of processing this is my current best image.

I have so, so much work to do to learn how to process correctly, but I'm quite pleased with the outcome so far. The stars (more notably the large one) are clearly distorted and I've had a real tough time removing the blue tint from my CLS filter. I'm really finding it hard to get a more "true" colour and get rid of the blue tint without making it green or yellow. Any advice here would be welcomes.

So here it is anyway. 20 x 90 sec exposures on Canon 1100D with Astonomik CLS filter, through ED80 on NEQ6 pro. No flats or darks yet. Mostly edited through Startools, then screenshotted and a JPEG loaded into PS (haven't yet paid for Startools) Between that, saving as a JPEG again and then uploading to photobucket, there's a fair bit of quality lost along the way here (excuses ).

Would love feedback and advice.

Get the camera astro modded, and then with the CLS filter the colour balance will then be almost perfect, i had the same problems, and like you say a nightmare to edit out, the CLS filter was designed to be used with a modded camera for almost perfect colour balance, was not designed tobe used with an un-modded one.

Hope that helps

MM

[roarke80]

Wow that's a beautiful pic.