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M51 First Attempt

Gerry Casa Christiana

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Craney

Craney

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I am going to have to revisit M51 now it is higher in the sky.  My 200 pds has yet to get this level of detail, although to be fair I usually don't do many subs and my mount aint as bomb proof as yours.  I like the flick of gas coming off top riight, usually seen in the captures of the more advanced imagers.  From my limited experience this is a good shot, well done.

(what length subs did you do ?? )

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Gerry Casa Christiana

Gerry Casa Christiana

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Thanks for the compliment. Yes it's a good subject right now and also M101 and others in the same area. I only did 120 second subs as my bomb proof mount will only reliably track for this time. In fact I had 29 subs but 9 went to the trash and that's good. I usually lose half! 

So what mount are you on? Heq5?

Gerry

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Craney

Craney

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Yep, the good ol' HEq5.   Having a 200 pds and a Canon 60D hanging off it, their is a bit of faith involved in getting 2min subs.  Sometimes it works.  At the moment I am going for diffuse nebula, but I do like galaxies... and there is only a few thousand to go at !!!!......along with everything else. 

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alacant

alacant

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Hi. Nice shot. 

13 hours ago, Gerry Casa Christiana said:

Any pointers cheers  I like it

'D' shaped stars: focus tube protrusion into main tube? I'm no expert but I think the focus is a touch wayward. Try ISO 800? But hey, it's all there. Well done. HTH.

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Waldemar

Waldemar

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15 hours ago, Gerry Casa Christiana said:

Hello all

I had a go last night at M51 20 subs @3200 bias 179 and 29 flat frames. Processed in Lightroom. 

Any pointers cheers  I like it.

 

IMG_4346.thumb.jpg.22fbaacf66d3681c76e7888d1c187418.jpg

 

Gerry

Hi Gerry,

Pointers? I hope you don't mind...:
As I see it: The stars on the outsides are elongated, especially in the top half of the picture. They seem to point at 2/3 down from the top of the picture, which means you have a bit of curvature (no flattener?) and the optical axes is not in the centre of your image.
To get a better result without changing anything, you could try focusing on the star above M51 @ 1 o'clock. Focus is a bit off as well. A flattener would be a nice addition.
If you already use one, you may want to change the focal distance between the flattener and your camera a little bit by trial and error. Baader Delrin spacers are great for that. 

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Waldemar

Waldemar

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13 hours ago, Gerry Casa Christiana said:

The best subs I ever got is when I pointed the focuser downwards! With my camera hanging underneath it! Just a pain when I want to look through the finderscope :) worked though much better tracking and less weight for balancing. 

All good fun 

In fact that is the best position for your camera. Because of a better radial balance that way, tracking will be better and RA balancing will lighter, too.

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Gerry Casa Christiana

Gerry Casa Christiana

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16 minutes ago, Waldemar said:

Hi Gerry,

Pointers? I hope you don't mind...:
As I see it: The stars on the outsides are elongated, especially in the top half of the picture. They seem to point at 2/3 down from the top of the picture, which means you have a bit of curvature (no flattener?) and the optical axes is not in the centre of your image.
To get a better result without changing anything, you could try focusing on the star above M51 @ 1 o'clock. Focus is a bit off as well. A flattener would be a nice addition.
If you already use one, you may want to change the focal distance between the flattener and your camera a little bit by trial and error. Baader Delrin spacers are great for that. 

No not at all. I appreciate it. I'm using a baader mpc 3 to correct coma. I think there could be a little movement in my focuser. Can I use a flattener apart from what I'm already using? The spacing is 55mm which baader says is correct. I keep checking it! :) could be the camera wasn't quite flat. I'll check my other pictures. Thanks for the pointers :) 

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Gerry Casa Christiana

Gerry Casa Christiana

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26 minutes ago, Waldemar said:

Hi Gerry,

Pointers? I hope you don't mind...:
As I see it: The stars on the outsides are elongated, especially in the top half of the picture. They seem to point at 2/3 down from the top of the picture, which means you have a bit of curvature (no flattener?) and the optical axes is not in the centre of your image.
To get a better result without changing anything, you could try focusing on the star above M51 @ 1 o'clock. Focus is a bit off as well. A flattener would be a nice addition.
If you already use one, you may want to change the focal distance between the flattener and your camera a little bit by trial and error. Baader Delrin spacers are great for that. 

The others are not the same. Maybe it was just collimation as I didn't do it because we had a friend over for a meal and I rushed it as it was already late. Probably that! 

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barkis

barkis

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Very creditable result Gerry, and bonus galaxies too.
The 450D is doing a good job for you. I have recently acquired a 150pds,
and I'd be very pleased with a similar result to yours. 
Not sure our UK skies will be as accommodating as the Italian ones though.
We need lady luck's help most of the time here :icon_biggrin:.
Well done.

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Waldemar

Waldemar

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5 hours ago, Gerry Casa Christiana said:

The others are not the same. Maybe it was just collimation as I didn't do it because we had a friend over for a meal and I rushed it as it was already late. Probably that! 

Ok Gerry, good to hear! The 55 mm distance for your MPCC may vary due to telescope 'flaws', so if you can try to get closer and further away a little like 0,5 mm and check the difference. May be a surprise!

A very nice but expensive program to solve all those kind of issues and more is CCD Inspector from CCD Ware. 

regards,

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Gerry Casa Christiana

Gerry Casa Christiana

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10 minutes ago, Waldemar said:

Ok Gerry, good to hear! The 55 mm distance for your MPCC may vary due to telescope 'flaws', so if you can try to get closer and further away a little like 0,5 mm and check the difference. May be a surprise!

A very nice but expensive program to solve all those kind of issues and more is CCD Inspector from CCD Ware. 

regards,

I had a look at the program. Hmm yes won't be buying that. Yes I'll give it a twiddle and see what's loose. I'll also check the focuser I think that's got loose somehow. 

 

Gerry 

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Waldemar

Waldemar

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12 minutes ago, Gerry Casa Christiana said:

I had a look at the program. Hmm yes won't be buying that. Yes I'll give it a twiddle and see what's loose. I'll also check the focuser I think that's got loose somehow. 

 

Gerry 

You can download a trial version and fiddle around with it... that will tell you what you need to know without buying...

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