Do I need dark frames?

[ApophisAstros]

2 hours ago, newbie alert said:

Take it that's a joke Roger??

maybe it's my monitor then.

Roger

[newbie alert]

2 hours ago, apophisOAS said:

maybe it's my monitor then.

Roger

Nothing wrong with your monitor, it's the soap bubble...

[ApophisAstros]

29 minutes ago, newbie alert said:

Nothing wrong with your monitor, it's the soap bubble...

not that , go to 11 o'clock to from the bubble , there appears to be a couple.

Roger

[tooth_dr]

28 minutes ago, apophisOAS said:

not that , go to 11 o'clock to from the bubble , there appears to be a couple.

Roger

It’s in all the images roger. It’s definitely not a dust bunny/pair of dust bunnies. 

[Allinthehead]

Another consideration with flats is that the bigger your sensor the larger the light drop off from the centre to the edges.

With my aps-c i find flats to be absolutely vital. While i can use gradient removal tools or even artificial flats to fix, i find the end results to be far superior with them. Bias/flat dark subtraction also needed for proper flats.

If your sensor suffers any amplifier glow then darks are also crucial. 

[Allinthehead]

No calibration autostretch

 

With calibration autostretch

Notice the bright center and dark edges on the the image without calibration.

[carastro]

Another example further to my comments earlier: 

Quote

 The middle is always brighter than the edges. 

Without Flats applied:

the flat itself 

Same image with flats applied

Edited November 19, 2019 by carastro

[newbie alert]

On 19/11/2019 at 10:21, carastro said:

Another example further to my comments earlier: 

Without Flats applied:

the flat itself 

Same image with flats applied

Hi Carole, would this be any different on narrowband rather than rgb filters as I've never experienced this so far..

 

[carastro]

To be honest I haven't tried narrowband images without flats given my experience with broadband, but might give them a try.

Carole

[tomato]

On 18/11/2019 at 12:55, ollypenrice said:

Aha, I was baffled when one camera lost its long-time column defect. Maybe I nutted it while fumbling around in the dark!

Olly

Isn’t that how you used to fix a dodgy TV in the old days, just give the set a tap or two on the side?☺️

[ollypenrice]

43 minutes ago, tomato said:

Isn’t that how you used to fix a dodgy TV in the old days, just give the set a tap or two on the side?☺️

The French NHS fixed my heart rate using the same technique...

ly

[newbie alert]

20 hours ago, carastro said:

To be honest I haven't tried narrowband images without flats given my experience with broadband, but might give them a try.

Carole

I mean the bright center ?

[carastro]

Quote

I mean the bright center ?

It's more like the corners are darker.  

Carole 

[newbie alert]

19 hours ago, carastro said:

It's more like the corners are darker.  

Carole 

Are your filters close as you can get them to the sensor?

[carastro]

Yes they are.

Carole 

[Marmo720]

I am currently dithering too and also taking darks so in same position of preferring to use the darks time to do lights if I don't need to do darks with dithering.

Just to check for those that don't do darks - do you use bias frames instead of darks in DSS? And leave the darks as empty? Not seen this in any tutorial and I am still learning.

Thanks,

Mo