DSS, what am I doing wrong

[bomberbaz]

I keep getting an error message from DSS when trying to stack with the message about it not debayering 8 bit images, camera settings below. Can someone help me so I can get it to work please.

TIA. 

[ZWO ASI183MC]
Debayer Preview=On
Pan=2
Tilt=0
Output Format=FITS files (*.fits)
Binning=2
Capture Area=5496x3672
Colour Space=RAW8
Temperature=13
Hardware Binning=Off
High Speed Mode=Off
Turbo USB=100(Auto)
Flip=None
Frame Rate Limit=Maximum
Gain=302
Exposure=1.466706
Timestamp Frames=Off
White Bal (B)=95
White Bal (R)=52
Brightness=8
Auto Exp Max Gain=225
Auto Exp Max Exp M S=30000
Auto Exp Target Brightness=100
Mono Bin=Off
Banding Threshold=35
Banding Suppression=0
Apply Flat=None
Subtract Dark=None
#Black Point
Display Black Point=0
#MidTone Point
Display MidTone Point=0.5
#White Point
Display White Point=1
Notes=
TimeStamp=2020-12-29T20:23:18.3195578Z
SharpCapVersion=3.2.6383.0
 

[vlaiv]

1 hour ago, bomberbaz said:

Colour Space=RAW8

Hope you did not spend too much time on this?

Here are two tips:

- don't shoot in 8bit mode, shoot in 16bit mode always

- don't use SharpCap for deep sky imaging.

Although from exposure length I would say this is more of EEVA style session? Then it is ok to use SharpCap, but for more serious work - use at least ASCOM drivers in SharpCap and preferably different long exposure capture application (NINA seems nice).

[bomberbaz]

8 minutes ago, vlaiv said:

Hope you did not spend too much time on this?

Here are two tips:

- don't shoot in 8bit mode, shoot in 16bit mode always

- don't use SharpCap for deep sky imaging.

Although from exposure length I would say this is more of EEVA style session? Then it is ok to use SharpCap, but for more serious work - use at least ASCOM drivers in SharpCap and preferably different long exposure capture application (NINA seems nice).

Thanks vlaiv, it is eeva, I don't do full on imaging, but this was the section to enquire about processing. 

I spent about an hour on capturing data, didn't realise it was in 8 bit mode. So are you saying this data is no good. 

[vlaiv]

28 minutes ago, bomberbaz said:

So are you saying this data is no good. 

In principle yep, that is what I'm saying.

8bit mode is just 16bit mode with removed least significant bits (lower 8bits of those 16) for faster transfer and less storage space. Since you used really high gain - you could recover something from the data - but you need to convert it to 16 bit first in order for DSS to accept it. However, I would not hold my breath since a lot of data has been just simply chopped off.

You can use 8bit when doing planetary  / lunar. There signal is so strong that loosing 8 lower bits is just loosing noise - most of the signal won't be affected because it is very strong. With faint stuff - most of the signal is in dark parts of the image and you discarded those dark parts of the image and that will impact the result.

Like I said - you can try to see what will come out of this data - but do keep in mind that data has probably been ruined by using 8 bit format and don't feel too bad if there is not much to look at after stacking.

[bomberbaz]

7 minutes ago, vlaiv said:

In principle yep, that is what I'm saying.

8bit mode is just 16bit mode with removed least significant bits (lower 8bits of those 16) for faster transfer and less storage space. Since you used really high gain - you could recover something from the data - but you need to convert it to 16 bit first in order for DSS to accept it. However, I would not hold my breath since a lot of data has been just simply chopped off.

You can use 8bit when doing planetary  / lunar. There signal is so strong that loosing 8 lower bits is just loosing noise - most of the signal won't be affected because it is very strong. With faint stuff - most of the signal is in dark parts of the image and you discarded those dark parts of the image and that will impact the result.

Like I said - you can try to see what will come out of this data - but do keep in mind that data has probably been ruined by using 8 bit format and don't feel too bad if there is not much to look at after stacking.

I will have a play with it, I love faffin around as it helps you learn.

One further question if you don't mind @vlaiv, what programme can I use to bulk change all the fits?

[vlaiv]

21 minutes ago, bomberbaz said:

I will have a play with it, I love faffin around as it helps you learn.

One further question if you don't mind @vlaiv, what programme can I use to bulk change all the fits?

Try ImageJ / Fiji (which is just distribution of ImageJ loaded with plugins, but you won't need plugins for this).

It opens / saves and will convert fits in bulk. This would be procedure:

- File / open image sequence / select folder and then use name to filter only subs you want to work with

that will open what is called a stack (just means bunch of images connected together that you can "browse" by using slider) - it won't stack them unless you request that in one form or another

 

(maybe it is better if I do few print screens).

- next, convert to 16 bit format:

It might ask something like "do you want all images to ...." - just click yes ...

- Last you do save image sequence:

It will ask for name and format - choose fits and give some name. Use other options to specify numbering of saved images (like img_01.fits, img_02.fits, ....)

And that is it.

[bomberbaz]

Thank you very much vlaiv. I have now found my fits files taken christmas eve of the jupiter/saturn conjunction are of the same 8 bit format. I hope I can change them too, rather more than these taken tonight.  

Images of pleaides can be got easily almost anytime, those of the above mentioned conjunction not so easily got.

[vlaiv]

6 minutes ago, bomberbaz said:

Thank you very much vlaiv. I have now found my fits files taken christmas eve of the jupiter/saturn conjunction are of the same 8 bit format. I hope I can change them too, rather more than these taken tonight.  

Images of pleaides can be got easily almost anytime, those of the above mentioned conjunction not so easily got.

For those maybe use AS!3 - it should load 8bit fits without any issues. It is after all planetary stacking software.

[bomberbaz]

24 minutes ago, vlaiv said:

For those maybe use AS!3 - it should load 8bit fits without any issues. It is after all planetary stacking software.

ASI3, not familiar with that one, do you mean ASI studio as used with ZWO camera's. Forgive my naivety.

[vlaiv]

10 hours ago, bomberbaz said:

ASI3, not familiar with that one, do you mean ASI studio as used with ZWO camera's. Forgive my naivety.

AutoStakkert! 3

https://www.autostakkert.com/wp/download/

 

[bomberbaz]

ah yes I have autostakkert. I shall have a play around. Much obliged as always vlaiv

[bomberbaz]

This is pleiades from the rescued data. One thing to bear in mind is they weren't that far away from the full moon. 

As you mentioned @vlaiv the recovered data wasn't great quality as I discovered trying to tease out detail in Gimp. But at least I managed a passable image.

Very happy with the focus, I tried out the new bahtinov mask from WOptics mask and feel it is far easier than using the standard black masks so worth the extra cost.

Anyway, lesson learned re: bit mode. 🙄 😅