california to 7 sister

[toxic]

well this is the best i can get from home so now i need to go to a dark site to do a comparison.

100 x 3 minute exposures no LP filter just stock camera eos 200d unmoded and stock 50mm lens on the SW SA image has a slight crop to get rid of stacking artifacts so image is now 5868 x 3492 stacked in DSS and processed in Photoshop

i cant wait to go to a dark site.

[happy-kat]

I'd be very pleased with that as well. Did you use calibration files.

[toxic]

1 hour ago, happy-kat said:

I'd be very pleased with that as well. Did you use calibration files.

thanks HK

no calibration files where used i should probably use darks at this iso the iso was 12800

 

[happy-kat]

Darks can be touch and go if they add more noise I am findijg, I like using flats and bias and recently been trying dark flats. Did you mask the calafornia neb area to selectively enhance more red or is that just from the number of lights you used?

[toxic]

35 minutes ago, happy-kat said:

Darks can be touch and go if they add more noise I am findijg, I like using flats and bias and recently been trying dark flats. Did you mask the calafornia neb area to selectively enhance more red or is that just from the number of lights you used?

no masking just whats in the subs just stretching and and levels in photoshop but i did use Nick collection with detail extraction about 15 percent free from google

[toxic]

ps i have never used bias frames as i am not sure what they are or what they do lol

[geordie85]

Awesome image. Once you get out to a dark site you'll be pleasantly surprised at the difference. I was.

[toxic]

thanks Geordie

[wimvb]

That's a great start on this object. From a dark site you can increase the exposure time, and get more signal in the weak areas. This will make it a lot easier to stretch the faint dust.

Bias frames are used to remove the read pattern of your sensor. This becomes important if you try to enhance faint details.

I think you should also definitely add flats. Flats remove any blemishes in the optical train, such as vignetting and dust bunnies. While vignetting can be removed during processing, you should try to reduce it at the source (= flats). Dark frames remove electrical faults in the camera: hot pixels and amp glow, mainly. But they need to match the light frames in exposure length and temperature. This last requirement may be difficult to achieve, especially if you have an uncooled dslr. That's why they may not work for you. There's only one way to find out ...

For all calibration frames (bias, darks, flats), you should take as many as is practical. The more you take, the lower the added noise.

If you have the possibility to dither (= move camera a few pixels in ra and/or dec between exposures), this will also improve your image quality.

[toxic]

thanks Wim i know about darks and flats but i havent a clue about bias frames or how to take them

[toxic]

sorted i now now abpout bias files lol thanks again Wim 

[wimvb]

They're the easiest to shoot, and maybe least needed. The information that bias frames provide, is already in the darks. If you subtract a dark master from your light frames, you also subtract the bias. With my cooled cmos, I only collect darks (for hot pixels and amp glow) and dark flats (to calibrate flats). Not bias anymore.

[gorann]

Yes, great start! I do wonder why you had the camera at ISO 12800. That will introduce noise. I never go above 1600 with my EOS 60D (I use 12 800 for the framing before I start exposing). Maybe you stopped the lens down a lot? If you have it around f/4 then you can use ISO1600 and 3 min exposures on this object.

Cheers

[toxic]

On 1/20/2018 at 09:22, gorann said:

Yes, great start! I do wonder why you had the camera at ISO 12800. That will introduce noise. I never go above 1600 with my EOS 60D (I use 12 800 for the framing before I start exposing). Maybe you stopped the lens down a lot? If you have it around f/4 then you can use ISO1600 and 3 min exposures on this object.

Cheers

thanks Goran and Wim

but if i stop it down to f4 the the stars are terrible so i have to compromise and the compromise is F7.1 and noise or F4 and rubbish stars and if the stars are deformed then any nebulosity will be deformed as well.

[gorann]

37 minutes ago, toxic said:

thanks Goran and Wim

but if i stop it down to f4 the the stars are terrible so i have to compromise and the compromise is F7.1 and noise or F4 and rubbish stars and if the stars are deformed then any nebulosity will be deformed as well.

I see, but ISO 12800 is a bit extreme when it comes to noise. Why not take longer subs - your mount should handle that easily especially in wide field (assuming you use the AZ EQ6). Then you could also start thinking about buying a Samyang for wide field - my 135 mm f/2 have very little (if any) coma at full opening (at least with APS-C sensors).

[toxic]

sorry only use the star adventurer with the Eos up to now i dont want to remove the atik from the 200 pds yet   its for the grab and go setup even though i haven't gone any where yet lol

[geordie85]

3 hours ago, gorann said:

I see, but ISO 12800 is a bit extreme when it comes to noise. Why not take longer subs - your mount should handle that easily especially in wide field (assuming you use the AZ EQ6). Then you could also start thinking about buying a Samyang for wide field - my 135 mm f/2 have very little (if any) coma at full opening (at least with APS-C sensors).

My Samyang 135mm has bare minimal coma wide open on my full frame 6d.

It truly is an AMAZING lens and great for wide-field shots especially from a dark site.

[gorann]

56 minutes ago, geordie85 said:

My Samyang 135mm has bare minimal coma wide open on my full frame 6d.

It truly is an AMAZING lens and great for wide-field shots especially from a dark site.

Yes, that little lens really shines!

[toxic]

2 hours ago, geordie85 said:

My Samyang 135mm has bare minimal coma wide open on my full frame 6d.

It truly is an AMAZING lens and great for wide-field shots especially from a dark site.

yes i am saving for 1 of them lenses but not there yet

 

[geordie85]

1 hour ago, toxic said:

yes i am saving for 1 of them lenses but not there yet

 

You won't be disappointed when you get there.

It's now my go to for imaging. 

[toxic]

cant wait to get it i bet it will be summer time so i will still have to wait lol