Hi Robin
A question for you
tell me if I'm wrong
I use 'Live Stacking' to capture the deep sky
-ON Align Frames
-ON FMHM filter
and
-Advance ---> Save & reset every (1) Minutes total exposure
In this way, many one minute files are created,
after I process all these files created with Deep Sky Stacker to have a single files (Autosave.tif)
is what I do correct?
can I also create/have a single file under Sharpcap without going through Deep Sky Stacker? or not
Tiziano
Live stacking one files
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Re: Live stacking one files
Hi,
it depends on what exposure you are using the camera at...
If you are using 5s exposures then you will be stacking 12 frames in each 1 minute, and that's kind of OK, but unusual
If you are using 1 minute exposures then you are only putting 1 frame into each stack in SharpCap, which is not the way you are supposed to use SharpCap live stacking.
It would be more normal to set the 'save and reset' to a value that means that SharpCap stacks maybe 20 or 30 exposures. You can even let SharpCap do all the stacking for you for a whole session (1 hour or more).
So, there is no *need* to use DSS, but some people do choose to do a number of shorter stacks in SharpCap rather than 1 long one. 1 minute per stack in SharpCap is unusually short.
cheers,
Robin
it depends on what exposure you are using the camera at...
If you are using 5s exposures then you will be stacking 12 frames in each 1 minute, and that's kind of OK, but unusual
If you are using 1 minute exposures then you are only putting 1 frame into each stack in SharpCap, which is not the way you are supposed to use SharpCap live stacking.
It would be more normal to set the 'save and reset' to a value that means that SharpCap stacks maybe 20 or 30 exposures. You can even let SharpCap do all the stacking for you for a whole session (1 hour or more).
So, there is no *need* to use DSS, but some people do choose to do a number of shorter stacks in SharpCap rather than 1 long one. 1 minute per stack in SharpCap is unusually short.
cheers,
Robin
Re: Live stacking one files
HI Robin
Your help,
how would you do the 'live stacking' setting for deep sky photos,
using short exposures, having an altazimutale mount, (Nexstar 6se), in order not to use DSS I could make a 60 minute file
(Save & reset every 60 Minutes total exposure)
with a single frame exposure of 4/5 seconds, what do you say in this way I would have a single file of 60 minutes with 900 exposures of 4 or 5 seconds each
Tiziano
Your help,
how would you do the 'live stacking' setting for deep sky photos,
using short exposures, having an altazimutale mount, (Nexstar 6se), in order not to use DSS I could make a 60 minute file
(Save & reset every 60 Minutes total exposure)
with a single frame exposure of 4/5 seconds, what do you say in this way I would have a single file of 60 minutes with 900 exposures of 4 or 5 seconds each
Tiziano
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- Site Admin
- Posts: 17384
- Joined: Sat Feb 11, 2017 3:52 pm
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Re: Live stacking one files
Hi,
a lot of complex decisions here...
Your minimum exposure is controlled by the read noise of the camera - the SharpCap smart histogram will help work out what that value is for your camera. Unless you have a lot of light pollution then 4-5s may be too short and may be hurting you both in terms of the amount of data to be processed and in terms of the read noise in every frame.
Maximum exposure is governed by the tracking accuracy of your mount, and in the case of an AltAz mount, the rotation rate - how long before you get visible problems with the stars in the corners due to field rotation.
These two considerations will hopefully give you a range of exposures to consider - maybe the minimum from the smart histogram is 25s and the maximum from tracking/rotation turns out to be 60s. You can then choose any exposure in that range and get basically similar results in the stacked image at the end of the session. Certainly stacking for 1 hour per stack would be fine.
In some cases you may find that the minimum recommended by the smart histogram is long enough that it causes tracking/rotation issues - then you either need to pick a compromise value or think about upgrading some of your equipment, since you will be struggling to get the best out of it.
cheers,
Robin
a lot of complex decisions here...
Your minimum exposure is controlled by the read noise of the camera - the SharpCap smart histogram will help work out what that value is for your camera. Unless you have a lot of light pollution then 4-5s may be too short and may be hurting you both in terms of the amount of data to be processed and in terms of the read noise in every frame.
Maximum exposure is governed by the tracking accuracy of your mount, and in the case of an AltAz mount, the rotation rate - how long before you get visible problems with the stars in the corners due to field rotation.
These two considerations will hopefully give you a range of exposures to consider - maybe the minimum from the smart histogram is 25s and the maximum from tracking/rotation turns out to be 60s. You can then choose any exposure in that range and get basically similar results in the stacked image at the end of the session. Certainly stacking for 1 hour per stack would be fine.
In some cases you may find that the minimum recommended by the smart histogram is long enough that it causes tracking/rotation issues - then you either need to pick a compromise value or think about upgrading some of your equipment, since you will be struggling to get the best out of it.
cheers,
Robin