28/03/19 - Tannenbaum M63

[8472]

53x 148s Lights

110 Darks

60 Flats

60 Bias

 

Olympus E-PL5

SW 1200mm 200p OTA 

AVX

 

Stacked in DSS

Processed in Startools and Gimp.

 

First imaging run with my Dob OTA on my AVX.

 

With the mount being on the limit, it could easily have been an exercise in futility, but the guiding (and first time dithering) proved surprisingly successful.

 

Despite my initial doubts, PHDMax also seemed to do an admirable job of dithering my un-tethered camera, too.

 

 

 

Kev

[+Derbyshire Dave]

Good result Kev, interesting detail in there. Was impressed with the idea of PHDMax for untethered cameras..

[8472]

Cheers, Dave.

 

As I said, I didn't know what to expect, on the night.

 

It's mainly all about coordinating the right dither and settle time with the pause gaps set in my intervalometer.

 

Let's hope the results are repeatable in the future.

[+RonC]

If you dithered, why waste imaging time doing Darks? I am trying a new regime, dithering then stacking Bios subs in the Darks on DSS. Seems to be working.. ?

[8472]

39 minutes ago, Ron Clarke said:

If you dithered, why waste imaging time doing Darks? I am trying a new regime, dithering then stacking Bios subs in the Darks on DSS. Seems to be working.. ?

Good point, Ron.

 

Strictly speaking you're right - there's no point, but I didn't use any imaging time. I took them overnight when the scope was back in storage, at home. 

 

Early days and I'm still experimenting,  but I'll re-stack without darks and see what the results are like at a later date. 

[+RonC]

OK, Bios subs taken at the fastest speed only take a minute or two. I do 20 them use them as Darks when stacking.

Let me know how you get on?

Ron

[8472]

Sounds interesting, I'll have to look into that. 

 

Anything that can increase imaging time sounds good to me. 

[+Derbyshire Dave]

Not using dithering at the moment, too much else to think about, but don’t know what Bios subs are..

 

can yiu explain please

[Peter Shah]

On 30/03/2019 at 09:44, Derbyshire Dave said:

Not using dithering at the moment, too much else to think about, but don’t know what Bios subs are..

 

can yiu explain please

Bias sub is the read noise from the camera this is another source of noise that need to be removed....easy to do just take either a 0s frame or as fast as you camera allows and calibrate the light frames with your darks and flats/

 

 

super pic by the way

[+Derbyshire Dave]

2 hours ago, Peter Shah said:

Bias sub is the read noise from the camera this is another source of noise that need to be removed....easy to do just take either a 0s frame or as fast as you camera allows and calibrate the light frames with your darks and flats/

 

 

super pic by the way

I’m being an idiot Peter. I know what a bias shot is, and I’ve taken them. There was a spelling mistake, it said BIOS, and I somehow thought that was something different ?

[8472]

 

On 29/03/2019 at 13:34, Ron Clarke said:

OK, Bios subs taken at the fastest speed only take a minute or two. I do 20 them use them as Darks when stacking.

Let me know how you get on?

Ron

Ron,

 

I've compared two separate DSS stacks, one with and the other without darks. Both of them were equally stretched (AutoDev) in Startools.

 

Initial impressions seem to point to the stack without darks exhibiting less noise (dark anomalies in Startools-speak), so it might indeed be that's the best way to go? 

 

At least in this type of image. 

 

With you substituting darks for bias frames, are you forgoing bias frames altogether, or using bias frames as bias frames as well, if that makes sense?

 

 

[+RonC]

Think I know what you mean. I'm not doing Bios frames as well, just used as Darks.

I've not done any comparative stacking, I'll try if I can find the time!!

 

Cheers

Ron

Edited April 6, 2019 by Ron Clarke
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