I've been testing different Iso settings and exposure lengths to see what will work in my Bertole 8 skies.
Attached is a single sub from last night. Conditions were perfect. On the back of the camera and in this sub, it appears that I've got some decent data to work with.
Then comes the stack !
Its a complete wash out
77 subs @ 150 sec. ISO 400 with CLS filter. 130mm F/5 Newt
I must have stacked it a dozen different ways and its the same.
I'm almost literally pulling my hair out.
Has anybody got any suggestions ? or do i need to just keep turning down my sub lengths until I get something worthwhile ?
Ryan, I have no idea what you know or don't know about stacking, or which software you are using, but with DSS that is the result that you should expect; you then have to manipulate the image in DSS or elsewhere to get
the final image, which you then move to your preferred processing software
such as Startools or Pixinsight or Photoshop for final tweaking. Hope this wasn't patronising.
raymo
Not patronising at all. Just high lighting missing information.
I've been stacking images for about a year now. Yes normally the stack is brighter than the single sub but this is to the extreme. I don't normally use the Newt under these skies as in the past I could only get decent length subs with my SCTs. I've just started guiding so I've been using the Newt at home and using my CLS filter. I just cant believe I cant get a 2.5min sub @ iso 400 without wash out. Is it a setting ? or is it just really really terrible skies that I will have to work out how to get around ( a stronger filter is on the cards ).
Is there a setting in DSS to keep this white out down ?
Before I hear about star tools..... I know, I used it, but it seems the glow is so bright that its mingled with the data. Like a limiting magnitude. Cut it out or tone it down and the feint detail goes with it.
You have to adjust the black point too. That will kill the white. That's perfectly fine.
Thank you Logan.
I normally do this in PS as part of my processing. To get rid of the white in this shot, I need to take it half way into the histogram curve and it destroys the whole image.
I'm more wondering if there's anything I can do to stop DSS making it so bright when it stacks the image or if its just more practice with the setup, inevitably reducing the sub length significantly.
Many of my images are so bright that nothing can be seen; this is fine, as said by lognic04. To get an image you can work with, do the following.
Below to the left of the final image you will see three colour sliders. Move any one of the three to the left until the tall corresponding colour cone intersects with the line of dashes that rises up from the bottom of the window and goes off to the right side of the window. Cone should intersect the line about 10-12mm from the bottom of the window. This will entail moving the colour cone a long way to the left. Do the same with the other two colour cones, making sure that the cones are as near as possible to forming a single cone. Click apply. The image will now appear. The sky background will be either too dark or too light; move the three cones left or right as necessary; note, the cones are very touchy to adjust. When the three cones are pretty much forming a single cone, your colour will be balanced. If there is an overall colour cast to the image, move the relevant colour cone to the left by the smallest amount that you can move it; can be fiddly. Don't tick the box at bottom left of the window to move all cones together, it doesn't work properly.
Try this, we can do other adjustments later if you wish.
raymo
And if the only solution with this setup is to reduce my capture. Which is better in peoples opinion ? To reduce the Iso and keep the sub length longer or to go with my cameras sweet spot of Iso 800 and massively reduce the length to say 1min ?
My thoughts are if I reduce the Iso, I'm still getting signal just weaker . Longer subs means less combined noise in the end product ?
Many of my images are so bright that nothing can be seen; this is fine, as said by lognic04. To get an image you can work with, do the following.
Below to the left of the final image you will see three colour sliders. Move any one of the three to the left until the tall corresponding colour cone intersects with the line of dashes that rises up from the bottom of the window and goes off to the right side of the window. Cone should intersect the line about 10-12mm from the bottom of the window. This will entail moving the colour cone a long way to the left. Do the same with the other two colour cones, making sure that the cones are as near as possible to forming a single cone. Click apply. The image will now appear. The sky background will be either too dark or too light; move the three cones left or right as necessary; note, the cones are very touchy to adjust. When the three cones are pretty much forming a single cone, your colour will be balanced. If there is an overall colour cast to the image, move the relevant colour cone to the left by the smallest amount that you can move it; can be fiddly. Don't tick the box at bottom left of the window to move all cones together, it doesn't work properly.
Try this, we can do other adjustments later if you wish.
raymo
Thank you Raymo. I'll give this a go. I've never used the adjusters in DSS, I've always done it in PS. This maybe what Im missing
You're welcome; its not a work around, its the normal workflow for DSS.
I also do the luminance and colour saturation in DSS, although I know most people don't.
cheers raymo
