First Light on the Pleiades

[+Derbyshire Dave]

I've been struggling, my mount has been broken, and only got it back last week, so two months out of the game. In that time I'd bought a William Optics GT81 and field flattener, so was more than a tad frustrated that I hadn't been able to use them.

So on Monday, managed to get a bit of clear sky to try  them out. Hoorah!

 

Managed to get 40 minutes on the Pleiades, 20 x 2 minute shots. No calibration frames.

 

This is the result..

 

So pleased with the kit, and can't get wait to get out again!

 

Cheers

[+Derbyshire Dave]

Whilst I'm really pleased with the resolution, the colour wasn't what I'd hoped for. I always think of the Pleiades as Blue.

 

My process was to use my modified Canon 1300d, then go into Photoshop and drag in the R,G and B graphs under levels, until they were all aligned. No surprise I guess that this doesn't leave any excess of blue. Any suggestions as to how to do this a different way would be very much appreciated.

 

So, from the shot above I tried to add some blue. Altered the colour balance by sliding Cyan/Red towards Cyan and Yellow/Blue towards Blue.

Also cropped in to add a bit of emphasis..

 

This is the result..  I have to say I quite like it, but would be interested in anything else I could have done earlier to get the result directly.

 

 

[+Derbyshire Dave]

Re colour balance, meant to add that as well as the modified camera, I was also using a CLS filter

[Tweedledee]

They're both nice in different ways, but overall I prefer the bluer version. ?

[+Graham]

Great shot Dave. 

Instead of doing the colour balance try this. 

In photoshop. 

Click on the image tab.

From the dropdown select adjustments.

Then select selective colour. 

You can then change the colours as and how you please. 

Just play with it. 

[+Bino-viewer]

How do you know how long to expose for, for an object like this...??

Is there a general rule of thumb ?

 

Would it have looked any different if you had taken 8 x 5 min subs ?

 

Or 40 x 1 min subs ??

 

Nice image by the way Dave.

 

 

 

 

[+Derbyshire Dave]

1 hour ago, Bino-viewer said:

How do you know how long to expose for, for an object like this...??

Is there a general rule of thumb ?

 

Would it have looked any different if you had taken 8 x 5 min subs ?

 

Or 40 x 1 min subs ??

 

Nice image by the way Dave.

 

 

 

 

Thanks Rob, yeah, I don't know if exposure would affect it. I like the blue version too, it's what you always see, but I feel I'm tinting it that way, rather than achieving it naturally.

 

When I use the CLS and the modified camera I always get three split peaks for the three colours, so I guess my normal technique of lining up those peaks makes my stars all white, and the nebulosity does too. I might try the same object with an unmodifield camera and /or no CLS and see if the results are different. Anyone else that can advise, I'd be really interested

[+Ibbo]

have a look here

 

Open your image in PS

levels

and align the black point of the red, green and blue, I give myself a bit of a buffer of about 10 or 20

 

 

 

 

 

[+Derbyshire Dave]

Steve, really appreciate that. Hectic today, I'll have a good look in the morning!

[+Bino-viewer]

Excellent video Steve, thanks for sharing it.

Adobe camera raw looks a very compelling choice....and no darks or flats !

 

 

 

[+Derbyshire Dave]

Wow, amazing! There's a load of stuff in there Steve, thanks. Haven't got the latest Camera Raw, or Registar, but will look into both..

[+Ibbo]

I bought registar a good few years ago (when i had some money)

It is not cheap but is very good at what it does.

 

Does anybody know if DSS stacker give the option to save the registered/aligned subs ?

[+Derbyshire Dave]

Not sure what you mean Steve. You can save the files used as a file list, so you can re-run the stacking process with different parameters.

The result is the autosavennn.tif file.

Do you mean somehow saving individual aligned subs after the stacking process for importing into another program? If so, not that I’m aware of..

[Guest]

On 13/12/2018 at 13:47, Bino-viewer said:

How do you know how long to expose for, for an object like this...??

Is there a general rule of thumb ?

 

Would it have looked any different if you had taken 8 x 5 min subs ?

 

Or 40 x 1 min subs ??

 

Nice image by the way Dave.

 

 

 

 

From what I know, there's no "one size fits all" answer,

[8472]

If it's any use to you, I'd forego the CLS filter Dave, unless the LP is absolutely unbearable.

 

I've stopped using mine since I realised it destroys the yellow wavelength channel. You cannot recover this, whatever software you care to use.

 

Looking back, all my images post CLS filter are pretty much devoid of yellow stars.

 

Since I stopped using it, LP does blow the histogram out sooner, but this can be dealt with in post, as long as it was left of centre to start with.

 

Nice first light with the WO.

 

YMMV

[+Derbyshire Dave]

On 24/12/2018 at 20:28, 8472 said:

If it's any use to you, I'd forego the CLS filter Dave, unless the LP is absolutely unbearable.

 

I've stopped using mine since I realised it destroys the yellow wavelength channel. You cannot recover this, whatever software you care to use.

 

Looking back, all my images post CLS filter are pretty much devoid of yellow stars.

 

Since I stopped using it, LP does blow the histogram out sooner, but this can be dealt with in post, as long as it was left of centre to start with.

 

Nice first light with the WO.

 

YMMV

Thanks Kev. I must admit, I've pretty much got used to using the CLS all the time. I have a sodium street light at the bottom of my drive, but after your comments, I'll definitely try some with and some without the CLS and do a comparison.