Losing detail in stacking

[Atacamallama]

I seem to be getting a "washed out" effect on stacking in DSS.

the file M27i is the stacked image of several hours data, but it has less detail inside the object than the individual frame also attached.

I have tried several stacking modes, but this effect is always present. It is rather ironic looking at the separate subframes in DSS with quite a lot of detail of the red cross stripes inside the object, for these then to disappear in the final stacked image.

any suggestions on what I am getting wrong?

TIA

[bogdog]

with all images stacked i think you still need to tweak the picture in photosop or whatever image app you prefer

here is your pic with curves adjusted,but you will do better i just tried without going into it more

http://i41.tinypic.com/rk62c8.jpg

[sgazer]

you need to tweak the resulting image in Photoshop. Staking will have improved the signal to noise ratio, so when you stretch the levels and curves, you can bring out even more finer detail without increasing the noise to much. A quick stretch of your stacked image shows there's plenty of detail still in there (looks a bit noisy because it a jpg, but your TIF output from DSS will be better).

[Atacamallama]

thanks for the replies. I do indeed tweak in PS, but that is not quite my point. The detail I am losing is the red cross inside M27. This is much more visible in the single frame, but in my stacked image it seems whited out. Bogdog, your image still seems to have this problem, although yours' sgazer seems to have recovered it.

I had an even more drastic case of this with M57, where I actually had to make the picture darker to pick up any detail inside the object....

[Psychobilly]

Stacking has resulted in the feint neubulosity in front of the Ha Cross now being visible ...

Imagine the nebula as a Ball of expanding dust edge on features will appear stronger as you are looking through more material ... the front parts will be thinner but will obscure the detail in the middle once you have sufficient data for them to become visible......

You sometimes see red channel noise in Ha rich targets which with enough data becomes the fainter outer shell...

Peter...

[jgs001]

When you're saving the image from DSS, are you saving with the changes embedded or applied ? The adjustments that you can make in DSS do work, to a point, but the author of DSS states on the website, that these are designed for getting an idea of the content and not for the final edit. They are really quite harsh in their effect, and this can cause you to have an effect of lost detail.... It's better to embed the adjustments and apply a gentle set of iterative adjustments in your preferred editor, than using DSS for the main tweaks.

[bogdog]

Bogdog, your image still seems to have this problem,

yeah as i said i only adjusted the curve twice and seen it wasn't washed out completely,if you work on it i'm sure you will get the result you are after

i'm no expert ..just learning myself here as i go along

[Atacamallama]

John, thanks for that. usually all i do is up the colour 20% in DSS and have the changes implemented, I am using a colour CCD and this seems the best way, but I'll look into embedding the changes again...

[Daniel-K]

it looks to me your white point is to high by this i mean your stretching it too far and its causing the center of m27 to blow out. also it looks like you need to bring the blue channel back into align with the red and green.

you have got good data you just need a few basic steps to get moving in the right direction, as said above a tiff would be better as a jpeg gets compressed and looks poop

[Atacamallama]

Astro Boy, thanks for that, although I have not done any stretching in that result. However, I think I am getting somewhere with Hyper Giant's suggestions and saving with changes embedded not applied.

I did this drizzled version which seems to have preserved a lot of the detail i was worried about:

[Daniel-K]

the drizzle looks really good!!