Thus Far and No Further!

[Moonshed]

4 hours ago, Squiddy said:

And I can only refer you to my previous post:

So my conclutions boils down to this as the less expensive way to go further:

New scope and an autoguider (with autoguider I meen both the guide scope and the camera. You need a computer to this setup though). Total investment of around £500. Maybe someone has another opinion about this, but this is my two cents. Try this first before getting the polemaster if it doesn't fit your budget. You can always buy one later...

Thank you Squiddy, I really do appreciate how you are trying to help me get better pictures with a minimum of cost and your advice is, I am sure, sound. It's just that I have decided that I am not going to spend any money on upgrading any equipment just to get better pictures. I may get the PoleMaster but only because it is becoming a matter of necessity.  That is the whole point I made with my opening post how one thing leads to another. I appreciate your help but am sticking with what I have. Thanks anyway?

[Moonshed]

On 8 January 2017 at 01:46, Thalestris24 said:

30-50 calibration frames of each type is usually sufficient, 100 is a bit ott, imho. 15+ lights is good as that allows you to use kappa-sigma stacking though, generally speaking, the more lights the merrier, so to speak. Don't select the dss options to align the colour channels. It's best to use dss just for stacking, and PS or Pixinsight for post-processing. Alternately the v2.9 dev version of Gimp is ok for basic processing (I've not checked the gimp site for a while but 2.9 was the version that enabled 16bit processing).

Louise

Hi Louise,

Good  news!  I have made up my Master frames, Darks, Lights and Bias/Offset, with 50 frames of each. I then went back to the original 20  Lights I used for the M42 image at the start of this thread, added the 3 Master frames and the improvement in the finished DSS stacked image is remarkable. No hicups at all. I used kappa - sigma as well which is also an improvement on the standard stacking system. It would seem my problem with DSS boils down to insufficient space in the memory, I cleared out a few years of photos, tons of them, and things have been great ever since.

Thanks for all your help. To think people were telling me to get a new computer because 4GB of RAM wasn't enough! Anyway, problem sorted. Thanks again. 

Cheers, Keith

[Moonshed]

I meant to post the two images for comparison but forgot. So here they are, straight off DSS with no processing at all. I can see that even with the improved  image there is something going on in the top left corner, but that's a small detail. I am eager to get working in PS and see how much better the finished image will be. (Still to finish the PS tutorial on Layers and Masks, so maybe I'll wait until then, or maybe not ?)

 

 

[Thalestris24]

Hi

Did you stack with flats? There seems to be noticeable vignetting which should disappear after stacking with flats... It's important to get flats right otherwise they can ruin the stacked image. Also maybe check your darks for any unexpected gradients etc. Also not sure where the diffraction spikes are coming from?

Louise

[Moonshed]

1 hour ago, Thalestris24 said:

Hi

Did you stack with flats? There seems to be noticeable vignetting which should disappear after stacking with flats... It's important to get flats right otherwise they can ruin the stacked image. Also maybe check your darks for any unexpected gradients etc. Also not sure where the diffraction spikes are coming from?

Louise

Hi Louise, Yes I stacked with all 3 Masters. Flats, Darks and Offset/Bias. I don't why I am getting diffraction spikes, no idea. However, regarding your comments I had a quick look at my Flats and noticed that over the 50 there is a difference. It started out okay but then the wind got up and some clouds blew in, so there is some variation from start to finish. I used a clean, white, and crease free cloth doubled over and held firmly in place over the scope. I will re-do them on a better, cloud free day. I will also check out the Darks carefully and see if there is anything there. I am clearly on the right track but haven't got there yet so will try again soon and take a lot of care over it. At least I know what I am doing now? and that the system works.  

Cheers .

Keith. EDIT: Just noticed on my earlier post "Good news...." I said Lights where I should have said Flats for the Master frames used in stacking. Sorry for the confusion.

EDIT. EDIT: Checked my Offset/Bias frames all 50 are the same, identical, plain blank, dark frames (taken at minimum  exp. 1/4000 sec.) nothing at all on them. Checked my Darks they are all identical. Each one has the identical pattern of about 40 "dots" scattered over each frame, all 50 the same, some white dots, some blue some a slight colour, but every frame identical. That would seem to me how it should be? Each taken same ISO as Lights and same exposure of 90 secs. The problem frames are definately  the Flats which I will re-take. The others are fine.

[Thalestris24]

Hi

I wonder, though, whether you've got your flats' exposure right - maybe you could post the master flat as .png?

Louise

[Moonshed]

2 hours ago, Thalestris24 said:

Hi

I wonder, though, whether you've got your flats' exposure right - maybe you could post the master flat as .png?

Louise

Hi, 

I just put the Canon to AV and let it do automatic exposure time for the Flats as I had read on a DSS site that was how it should be done, I have not come across any other way of doing it but maybe there is, I don't know. However, as always, I am open to advice. I will have a go at posting you the Master Flat as a .png, but it will probably be in the morning. Thanks.

Keith

[Moonshed]

3 hours ago, Thalestris24 said:

Hi

I wonder, though, whether you've got your flats' exposure right - maybe you could post the master flat as .png?

Louise

Hi Louise,

Here is the Master Flat posted as a .png as requested.

As I said I will be re-doing the flats as there were some variations throughput the run due to the weather, I will pick a better day for it next time. Thanks.

Keith

[Thalestris24]

5 hours ago, Moonshed said:

Hi Louise,

Here is the Master Flat posted as a .png as requested.

As I said I will be re-doing the flats as there were some variations throughput the run due to the weather, I will pick a better day for it next time. Thanks.

Keith

Hi

That looks ok, though I'm not well up on on sct flats. Yeah, av exposures should be fine for unmodded dslrs. I find it best to use a fixed light source for flats in order to get even illumination and avoid unwanted gradients. In, fact I've recently just been using artificial room light and taken shots of a plain white a4 sheet - no t-shirts or anything. Seems to be ok. Oh, make sure there are no leds on with your camera and switch the lcd screen off - an make sure the viewfinder is covered.

Louise

[Squiddy]

On 2017-01-08 at 19:37, Moonshed said:

Thank you Squiddy, I really do appreciate how you are trying to help me get better pictures with a minimum of cost and your advice is, I am sure, sound. It's just that I have decided that I am not going to spend any money on upgrading any equipment just to get better pictures. I may get the PoleMaster but only because it is becoming a matter of necessity.  That is the whole point I made with my opening post how one thing leads to another. I appreciate your help but am sticking with what I have. Thanks anyway?

Oh, I think I misunderstood you a bit. In this case I can assure you that the polemaster will make your life much easier  

[Moonshed]

2 hours ago, Squiddy said:

Oh, I think I misunderstood you a bit. In this case I can assure you that the polemaster will make your life much easier  

Okay Squiddy no problem ? Yes, the PoleMaster sounds ideal. I have made enquiries  with the UK supplier and they do stock an adapter for my mount. I think I will go ahead and order it because as you say, it will make my life a lot easier. Many times when I have been struggling to get PA I have got close but then been forced to stop because of back pain and just had to make do. It would be so good to do it inside my "moonshed" looking at my laptop screen instead, and get it spot on!

[Moonshed]

3 hours ago, Thalestris24 said:

Hi

That looks ok, though I'm not well up on on sct flats. Yeah, av exposures should be fine for unmodded dslrs. I find it best to use a fixed light source for flats in order to get even illumination and avoid unwanted gradients. In, fact I've recently just been using artificial room light and taken shots of a plain white a4 sheet - no t-shirts or anything. Seems to be ok. Oh, make sure there are no leds on with your camera and switch the lcd screen off - an make sure the viewfinder is covered.

Louise

Hi Louise, okay, thanks for that. Here in Norfolk it is blue sky and sunshine at the moment so I have taken another 50 Flats, this  time all the same, and will make a new Master Flat.

Keith