PROBLEM HELP

[Anthony1979]

ive stacked 69 lights and 40 flats in dss and put it through gimp and my image has come out like this and i dont no why because this has never happened before .. never  had any problems like this.... have i clicked on something in dss i shouldnt have........ really frustrating

[Mr niall]

Have you tried stacking it without the flats?

[tooth_dr]

Looks like a really nice image, I think I would do as Niall says and try it without the flats.

[Anthony1979]

I mean the colour i dont no why its come out like this... Its never done this before.... When i use the stacked image in gimp and use level and curves the colour come out lighter and lighter..... Im not bothered about the flats thats just  another problem to solve another day.... Its just this colour.. Its never come out like this before

[tooth_dr]

Just now, Anthony1979 said:

I mean the colour i dont no why its come out like this... Its never done this before.... When i use the stacked image in gimp and use level and curves the colour come out lighter and lighter..... Im not bothered about the flats thats just  another problem to solve another day.... Its just this colour.. Its never come out like this before

The flats can cause that colour issue

[Anthony1979]

So theres nothing i can do about it.... Its never happened before when ive tried using flats

[Knight of Clear Skies]

I've had lots of similar problems with flats over-correcting in DSS. Often I just use the GradientExterminator plugin for Photoshop to remove any vignetting.

If you put the stacked image without flats on Dropbox I could have a quick go at sorting it out.

Edited April 23, 2020 by Knight of Clear Skies

[tooth_dr]

10 hours ago, Anthony1979 said:

So theres nothing i can do about it.... Its never happened before when ive tried using flats

If you want to resolve this, you need to take steps to work out the issue.

1) try without flats - is the problem still there?

2) if problem is not there with current flats - take new flats

3) try again with flats - is the problem still there?

Then let us know the result.

[Anthony1979]

3 hours ago, Knight of Clear Skies said:

I've had lots of similar problems with flats over-correcting in DSS. Often I just use the GradientExterminator plugin for Photoshop to remove any vignetting.

If you put the stacked image without flats on Dropbox I could have a quick go at sorting it out.

I dont no how to use dropbox sorry

[tooth_dr]

1 minute ago, Anthony1979 said:

I dont no how to use dropbox sorry

Can you post the stack of 69 lights here, without any flats, just the lights, stacked in DSS?

And then post the stacked flat that DSS saved 'MASTER FLAT'

 

We can definitely get to the bottom of this for you.

[Anthony1979]

Yes im just re stacking my lights again 

[Anthony1979]

Im having to re stack flats aswell because i deleted everything i stacked last night in frustrating so may take a while

Edited April 23, 2020 by Anthony1979

[david_taurus83]

Flats with a DSLR are difficult and something I'm grappling with myself. If I could clean my sensor of all dust spots I'd try and image without flats.

[Anthony1979]

1 hour ago, david_taurus83 said:

Flats with a DSLR are difficult and something I'm grappling with myself. If I could clean my sensor of all dust spots I'd try and image without flats.

I can deal with the flats problem that will be my next question....its mainly where has this nasty colour come from

[david_taurus83]

1 minute ago, Anthony1979 said:

I can deal with the flats problem that will be my next question....its mainly where has this nasty colour come from

The flats can affect the colour balance.

[Anthony1979]

OK.....  These are all re-stacks all the same as the pic above.... First i re-set to default in dss and the only change i made was ;

In RAW/FIT DDP Setting - i clicked in white balance - use camera white balance..

In Stacking settings - i clicked lights - kappa sigma clipping

Everything else is left as default

Now all that nasty colour has gone i think

OK here are the stacks i had just done

 

MasterFlat_ISO400.tif M101 - LIGHTS 72x60.TIF

[Anthony1979]

This is  a lights and darks stacked... but im still getting this red colour... 

so could it be some setting in dss 

[barkis]

It is a fine Image too, so well worth pursuing the problem to correct it.

Ron.

 

[Tommohawk]

Your image looks good, maybe a bit red... But my colour vision is awful!

There is an "align RGB histo" feature in DSS which should help with colour balance. Can't remember exactly where this is.

BTW what camera are you using and is it modded?

[Anthony1979]

4 hours ago, Tommohawk said:

Your image looks good, maybe a bit red... But my colour vision is awful!

There is an "align RGB histo" feature in DSS which should help with colour balance. Can't remember exactly where this is.

BTW what camera are you using and is it modded?

Nikon d3500 unmodded

[Anthony1979]

I think ive resolved the colour issues... I think it was the colour balance settings in raw/fit ddp setting... So im stacking AGAIN.... See what happens.... I was still at it till 4 this morning

Edited April 24, 2020 by Anthony1979

[david_taurus83]

Hi Anthony, I had a play with those stacks myself in Pixinsight and Photoshop. The flat looks fine, its well exposed and picks up all the dust spots. The uncalibrated light stack looks ok as well but for some reason there are streaks where the worst dust spots are. Also a horizontal band near the top that looks like the edge of a frame. Did you move the camera at all during the capture? The flat shows donuts where the dust is. If the dust was on the camera sensor they usually stay put even if you move the camera but as they are streaked on the image I reckon they are on the secondary mirror. That said, its a fine effort and a lot better than my first attempt at M101 with a newt. I've debayered and over stretched the flat so you can see the dust donuts and I've removed the gradient in Photoshop and brightened the background of M101 so you can see the streaks made by the dust donuts.

[Anthony1979]

I removed the camera when i was packing up and forgot i had to do my flat so i put it straight back after realizing (i know big mistake)...  But apart from that the camera was secure during the session... The secondary looks perfectly clean.. Thanks

Edited April 24, 2020 by Anthony1979

[happy-kat]

Did your stack include a frame or frames taken out of sequence ie time period was different?

[Anthony1979]

All my lights were taken continuously during the night.. The flats were taken day after