Is this a normal amount of noise for a 6400 iso, 1" sub?

[Cakedestroyer]

After looking at some videos it seems to me I have a lot of red/purple light in my shot. Is this more than you would think I should see? I am going to attempt to again tonight and just want some advice. I do have the iso at 6400 so I was wondering if I need to lower it to 3200?

One other thing is I am 99% sure but I would not be very happy with my self if I was taking so much time so just wanted to check, the middle "star" of those 3 is the Orion nebula right?

Thanks and clear skies!

[Mr Spock]

It would help to know what camera your are using. Some are good at hight ISO, some aren't 

[Cakedestroyer]

33 minutes ago, Mr Spock said:

It would help to know what camera your are using. Some are good at hight ISO, some aren't 

Thanks for your reply. I am using a canon 60d with the kit 55-250mm lens. Do you think this is bad enough I should go down to 3200 even if I am going to stack a good 300-600 light and do all the bias (flat, dark and bias) frames?

[Alien 13]

The reported "best" ISO for the Canon 60D is 800, have a look here.

Alan

[Cakedestroyer]

9 minutes ago, Alien 13 said:

The reported "best" ISO for the Canon 60D is 800, have a look here.

Alan

Thanks!
Is it ok to go a bit higher than 800 or is that pretty much a hard limit?

[Alien 13]

1 minute ago, Cakedestroyer said:

Thanks!
Is it ok to go a bit higher than 800 or is that pretty much a hard limit?

There are no hard limits but you might not gain anything by going higher, 1600 might be OK though depending on conditions.

Alan

[Cakedestroyer]

Just now, Alien 13 said:

There are no hard limits but you might not gain anything by going higher, 1600 might be OK though depending on conditions.

Alan

Ok, I might go for 1600 then. I think it was probably good that I asked before I used 6400 for another night. Does this mean I will need to increase the amount of shots I take? I am currently planning on about 500 subs at 1" which would be a total exposure time of 8 minutes and 20 seconds.

 

Thanks!

[Alien 13]

5 minutes ago, Cakedestroyer said:

Ok, I might go for 1600 then. I think it was probably good that I asked before I used 6400 for another night. Does this mean I will need to increase the amount of shots I take? I am currently planning on about 500 subs at 1" which would be a total exposure time of 8 minutes and 20 seconds.

 

Thanks!

What lens or scope are you using and is it on a static tripod?

Alan

[david_taurus83]

It's noisy because the background noise (bias signal) is dominant due to such a short exposure. The only way to overcome this is to expose for longer or shoot many many more subs, which will then require some time on your PC for processing and stacking. Orion is a bright target so you really don't need to go higher than ISO800. Are you shooting from just a tripod with no tracking?

[Cakedestroyer]

3 minutes ago, Alien 13 said:

What lens or scope are you using and is it on a static tripod?

Alan

Just a static tripod and efs55-250mm lens. This will be my second attempt at dark sky after the failed attempt a few weekends ago. After I do this a bit more I think I might grab a star adventurer 2i pro pack or something.

Bad new is it seems like the clouds are moving in for tonight . Hopefully the cloudy streak ends soon!

[Cakedestroyer]

2 minutes ago, david_taurus83 said:

It's noisy because the background noise (bias signal) is dominant due to such a short exposure. The only way to overcome this is to expose for longer or shoot many many more subs, which will then require some time on your PC for processing and stacking. Orion is a bright target so you really don't need to go higher than ISO800. Are you shooting from just a tripod with no tracking?

Ok. I did have a good 500 or so shots but I messed up my bias frames so I need to try this again another night. So you don't think there is any advantage in going from 800 --> 1600?
I am just using a static tripod but if I do this a bit more I am looking forward to getting a star tracker/mount.

Edited October 14, 2022 by Cakedestroyer

[david_taurus83]

Just now, Cakedestroyer said:

Ok. I did have a good 500 or so shots but I messed up my bias frames so I need to try this again another night. 
I am just using a static tripod but if I do this a bit more I am looking forward to getting a star tracker/mount.

How did you mess up your bias frames?

[Alien 13]

1 minute ago, Cakedestroyer said:

Just a static tripod and efs55-250mm lens. This will be my second attempt at dark sky after the failed attempt a few weekends ago. After I do this a bit more I think I might grab a star adventurer 2i pro pack or something.

Bad new is it seems like the clouds are moving in for tonight . Hopefully the cloudy streak ends soon!

Are you using the 400 rule to determine exposure time for example 400/fl =time in seconds before trailing becomes obvious so if you had the lens at 200mm then 400/200 =2seconds.

Alan

[Cakedestroyer]

4 minutes ago, david_taurus83 said:

How did you mess up your bias frames?

Wrong exposures and iso for the darks, and other issues with the other types

[Cakedestroyer]

4 minutes ago, Alien 13 said:

Are you using the 400 rule to determine exposure time for example 400/fl =time in seconds before trailing becomes obvious so if you had the lens at 200mm then 400/200 =2seconds.

Alan

Yeah. Due to this camera having a crop factor of 1.6 I have 250mm * 1.6 which is 400 so one second. I tried the npf rule and got similar results.

[almcl]

1 hour ago, Cakedestroyer said:

One other thing is I am 99% sure but I would not be very happy with my self if I was taking so much time so just wanted to check, the middle "star" of those 3 is the Orion nebula right?
 

Yes, indeed it is.

Here's your image overlaid on a star map:

[Cakedestroyer]

1 hour ago, almcl said:

Here's your image overlaid on a star map:

Awesome! Thanks for the cool map, did you make it or use a tool? Seems like a cool thing to be able to use if it's like a website.

[michael8554]

Had you left LiveView on ?

Michael

[happy-kat]

The lens is still 250mm crop/smaller sensor has a smaller field of view it does not alter actual magnification.

Pointing at targets to the East and West with altitudes between roughly 20-50 degrees minimises how fast star trails appear.

[Cakedestroyer]

41 minutes ago, michael8554 said:

Had you left LiveView on ?

Michael

I think so, yes.

Cake

[Cakedestroyer]

16 minutes ago, happy-kat said:

The lens is still 250mm crop/smaller sensor has a smaller field of view it does not alter actual magnification.

Pointing at targets to the East and West with altitudes between roughly 20-50 degrees minimises how fast star trails appear.

Ok. All the videos I have been watching say you need to multiply the focal length by the crop factor for the rule of 400/500. I do know about how long to expose for, I am mainly not as sure about the iso.

[happy-kat]

I to use the rough /500 divide as I don't use full frame though the direction the target is does have quite an influence on star trails. If you stack using intersection that deals with a fair bit of field rotation. With canon cameras some users are finding darks add more noise, I don't take darks but I like flat darks as well as flats (same as flats just add lens cap).

 

 

 

[Cakedestroyer]

9 minutes ago, happy-kat said:

I to use the rough /500 divide as I don't use full frame though the direction the target is does have quite an influence on star trails. If you stack using intersection that deals with a fair bit of field rotation. With canon cameras some users are finding darks add more noise, I don't take darks but I like flat darks as well as flats (same as flats just add lens cap).

Just to make sure I have them all right:
Lights - The photos of stars

Darks - Same settings, lens cap on
Bias - 1/8000th second/fastest exposure and lens cap (/body cap?) on
Flat - White thing over end of lens and phone behind it, move histogram to middle?

I can't change the direction of the target I am trying to shoot but I'll bear it in mind for the future.

Thanks!

[happy-kat]

Flat same iso as lights (and focus) but flat light source

Dark flat same as flat but with lens cap

Have an experiment with your camera you might find dark flats add noise. 

 

[Swillis]

It might be worth trying a few different exposure lengths to determine what the longest practical exposure is and when you start to see star trailing. 

Increasing from 1 to 2 sec would probably be a big difference noise. 

General advice with canon DSLRs is not to use darks (or dark flats I guess?). As they do something in the background which removes the dark signal.