M42 - 31.1.2010 (first Guided image)

[Carole]

This is probably going to be a bit of a disappointment after all the anticipation but I suppose it's better than my last attempt and you can just make out "the running man".

I am having great difficulty enhancing images in colour (they look vile), so I have converted to B&W, I guess I'll learn eventually.  At least I got the guiding to work at long last.

So herewith:
M42, Sunday 31.1.2010
20 x 180secs, darks, flats and Bias minus 0.5 degrees
Canon DSLR 450D, CLS filter
WO Megrez 72 APO F/6 72mm aperture
Stacked in DSS and enhanced in photoshop (must try to improve on this).

I don't know why but the 5 min x 12 subs that I also did on the same evening stacked,  but I could not improve them afterwards.  Done at the same "sitting" with same set up etc etc

[Mac]

Good image for your first attempt at guiding.

All you need to do is to just nail the focusing, as it's just out of focus ,
Are all the subs the same?
As for your colour stacking, how exactly are you attempting to do this?

Post one of your

vile

ones for a comparison.
It might be just the way you are stacking them?

When you use the 450d, do you use the live view to help you in your focusing?
and or do you use a focus mask?

Apart from that,
now you have the guiding sorted, hope to see some more from you.
weather permitting.

Mac.

[Carole]

Thanks Mac,

All you need to do is to just nail the focusing, as it's just out of focus

Yes, this is proving to be a difficult aspect for me.  I cannot see the object in live view (although I forgot you told me to UP the ISO temporarily).  I focused on sirius with the focus mask and it seemed OK, then moved to M42, took lots of short images with the focus mask until I thought it was in focus, but obviously I still need to get this right.

Are all the subs the same?

I guess so, I didn't change the focus.

Re:the vile colour ones

It might be just the way you are stacking them?

It's not the stacking that's the problem it is when I try to stretch the image afterwards.

I'm not sure I want to put a VILE one on public display, might wait until the imaging session, or when I can show some-one on the laptop.

Carole

[Mike]

Like Mac says, the guiding looks good, just need to sort the focus out and it would have been a half decent image.

You're getting there! Persevere !

[Carole]

Thanks Mike, I've sweated blood to get this far, but determined not to let it beat me.
Just sorry I've taken up so much of every-one else's time on the way.  Especially with the SC3 which Mark has finally confirmed does not work in LX. 

Carole

[RobertM]

That's a very good attempt Carole.  To nail the focusing, make sure the optics are cooled down, slew to a bright star and use the focus mask to focus, then "DO NOT TOUCH" and slew to the target, image and go...  If you use a Bhatinov mask then Mars is a good target to focus on as I did the other night.  You may notice the focus shift overnight but it should be minor compared with what you recorded.

As we keep saying, it's a very steep learning curve but persevere and the rewards are well worth the effort.

Robert

[Carole]

Thanks Robert:

To nail the focusing, make sure the optics are cooled down,

The scope is kept in my conservatory which currently is VERY cold, so optics are already cooled. 

slew to a bright star and use the focus mask to focus, then "DO NOT TOUCH" and slew to the target, image and go...

that's exactly what I did.  I also checked with the focus mask on M42. It's very annoying as I'm doing all the right things, and it looks to be in focus at the time, I just wish I could see what I am focussing when I do the focussing!!!!  Just have to keep going until I get it right.

Carole

[MarkS]

Guiding works!

It's quite possible that you focus accurately and then something moves afterwards - is everything held in place securely and is the drawtube locked in place?  I made this basic error (yet again!) at the weekend when imaging Mars with eyepiece projection - I forgot to tighten the eyepiece in its holder causing the focus to drift off.

In any case - always check your first sub carefully (zooming right into the image), just to confirm that it really is in focus.

Especially with the SC3 which Mark has finally confirmed does not work in LX.  

We found that attempting to use LX mode crashed PhD (in Vista) - which I think Duncan has also found (if I remember correctly).  

Mark

[Carole]

is the drawtube locked in place

Yes, I locked it in place.

always check your first sub carefully (zooming right into the image), just to confirm that it really is in focus.

Did that too.  It was fine with the focus mask, no triple stars or small stars with rings.

Maybe my eyesight is letting me down.  I am starting to wonder about my monovision contact lenses which give you reading vision in one eye and normal sight vision in the other eye, it's not perfect vision says the optician but enables me to wear contact lenses like bifocals.  Maybe I need to swap back to glasses once I've done with looking through eyepieces which I find difficult with glasses on.

There is obviously something I am not getting quite right, it's just finding out what it is.

Just wondering if I can re-create that trick you do with your C11 on my Megrez, but not sure how I can adapt it to my set up. Need to have a think about this. 

Carole

[Fay]

Well they are getting better as you go along, Carole. Sort your focusing & then there will be a big improvement

[Carole]

Thanks Fay.  Hopefully I can get some help at DSC if I haven't sorted it by then.

Carole

[MarkS]

Carole,

So the stars were sharp in your first sub and then later subs became gradually de-focused?

The "C11 trick" (slewing the scope whilst altering the focus in steps) I already use on the ED80 and I also plan to use it on the Tak Epsilon.  Though I might also experiment with Nebulosity's focusing tool (which measures FWHM of stars).

Mark

[Mike]

Sounds like your focus lock needs adjustment.

[Carole]

So the stars were sharp in your first sub and then later subs became gradually de-focused?

No, what I mean is, it looked focussed to me, as the focus mask had merged the 3 stars, and when I zoomed in to an image I had done a short exposure of, again it looked focussed to me.  I had also focussed Sirius with the focus mask before I moved to M42 but that was very faint as well.  

I've just looked at a less enlarged version of the above and it looks more focussed when it is smaller.  I think part of the problem here is not being able to see the image sufficiently well enough to tell if it's truly in focus. I shall just have to find a way to overcome it.  

The "C11 trick" (slewing the scope whilst altering the focus in steps) I already use on the ED80

.  Must find out how you do that on the ED80 Mark.  

Carole

[Mac]

I think part of the problem here is not being able to see the image sufficiently well enough to tell if it's truly in focus. I shall just have to find a way to overcome it. 

plug the camera in to the pc. (Yup more cables )

and have a look at the image on the laptop screen.

Mac.

[Carole]

plug the camera in to the pc. (Yup more cables )and have a look at the image on the laptop screen.

I'm already plugged into the laptop, and as I have said before, M42 is too faint to show up on the screen in live view.  I can only look at it when I've grabbed a short image, and even then I don't think it is sufficiently large enough to be able to judge whether it's truly in focus.

I have now had a go at trying to process this in colour.
I've made the image a little smaller so the lack of focus is not quite so obvious.



Carole

[Mac]

I can only look at it when I've grabbed a short image, and even then I don't think it is sufficiently large enough to be able to judge whether it's truly in focus.

Er. why.

Granted live view might be a tad small when looking at the back of the camera, but that also has a zoom function.

But when you have taken a short exposure at high iso,
say 10secs at 800 or even 1600.
The image size your camera produces will be HUGE 4272 x 2848

so by using the laptop screen and zoomin in to the image you will be able to see if its in focus or not..

Your camera is a 12 megapixel camera!!!
Your laptop screen if its 1024 * 768 which is the average size is only 1Megapixels so the image will be huge!!

Heres a 12 Megapixel image (Highly compresed) sorry for the large post,

Your images should be the same size as this one!!


so you should be able to see one of the stars in the image and easily see if it is in focus with the focus mask.

If your image in not this size or even close.
Check that you have the correct settings for your camera.
Raw + Jpg (use the jpg so that you can see if its in focus)

Make sure the Jpg is set to large + fine.

If your going to DSC in a few weeks, im sure we can nail this focus in one hit.

Mac.

[Carole]

Ah ha!!!

Raw + Jpg (use the jpg so that you can see if its in focus)

I think this has hit the nail on the head.  I've had the camera set on RAW only, and can only look at images in Digital photo professional as no other programmes on my laptop will open in RAW.  The images are not that big when you open them (see example below).

YES, if I take the focussing images in JPG I can open and zoom in any other program on my laptop.  

Never thought of that, will try that next time.  All a big new learning curve, and learning by my mistakes.
Thanks Mac.

Just to show you what I was looking at in Digital photo professional and you can't zoom in any more than this - this is a single frame, perhaps you can see now why I could not tell it was out of focus.


Yes planning to go to DSC weather permitting.  i.e. not going if it's freezing.
Don't mind freezing for a few hours to do imaging if there's a warm house to come back into but can't face a whole weekend of freezing.

Carole