Aaaarrrrgggg, Help

General discussion about StarTools.
ChrisLX200
Posts: 90
Joined: Tue Apr 22, 2014 10:25 am
Location: Macclesfield, UK
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Re: Aaaarrrrgggg, Help

Post by ChrisLX200 »

Bias and flats you need, but darks are a bit of a waste of time with DSLRs because the camera is not temperature controlled and so it's very difficult to obtain a valid master dark (the camera will heat up significantly during exposures unless you get rid of the battery and use an external power supply, and even then it still gets warm enough for extra pixels to light up).

ChrisH
MadMaxwellSmart
Posts: 20
Joined: Thu Jun 26, 2014 1:12 am

Re: Aaaarrrrgggg, Help

Post by MadMaxwellSmart »

ChrisLX200 wrote:Bias and flats you need, but darks are a bit of a waste of time with DSLRs because the camera is not temperature controlled and so it's very difficult to obtain a valid master dark (the camera will heat up significantly during exposures unless you get rid of the battery and use an external power supply, and even then it still gets warm enough for extra pixels to light up).

ChrisH
Hey Chris, Flats really seem to over run my image when I take them (for Camera only Wide Field) prime focus they work just fine...seems they are really over powering...and you may know this question, Ivo advised me to turn off the (al channel calibration/alignment in DSS) I can't find where to turn this off...I am using DSS 3.3.3 Beta 47. Thanks Chris
ChrisLX200
Posts: 90
Joined: Tue Apr 22, 2014 10:25 am
Location: Macclesfield, UK
Contact:

Re: Aaaarrrrgggg, Help

Post by ChrisLX200 »

MadMaxwellSmart wrote:
ChrisLX200 wrote:Bias and flats you need, but darks are a bit of a waste of time with DSLRs because the camera is not temperature controlled and so it's very difficult to obtain a valid master dark (the camera will heat up significantly during exposures unless you get rid of the battery and use an external power supply, and even then it still gets warm enough for extra pixels to light up).

ChrisH
Hey Chris, Flats really seem to over run my image when I take them (for Camera only Wide Field) prime focus they work just fine...seems they are really over powering...and you may know this question, Ivo advised me to turn off the (al channel calibration/alignment in DSS) I can't find where to turn this off...I am using DSS 3.3.3 Beta 47. Thanks Chris
It's not easy generating a good set of flats for wide-field (short focal length) camera lenses, flats are supposed to be taken using the same focus setting as the light frames which makes things difficult trying to find a suitable evenly lit background. In the absence of a proper light box a white bedsheet hanging on a washing line a few feet away, lens set at infinity on an overcast day should do it. Might not be perfect but should be a heck of a lot better than no flat at all - and make life easier for removing any remnant gradients during PP.

Not sure what that setting is referring to - perhaps the 'Align RGB Channels in Final Image' check box on the 'Results' tab under the stacking settings? You can try it both ways and see.

ChrisH
MadMaxwellSmart
Posts: 20
Joined: Thu Jun 26, 2014 1:12 am

Re: Aaaarrrrgggg, Help

Post by MadMaxwellSmart »

ChrisLX200 wrote:
MadMaxwellSmart wrote:
ChrisLX200 wrote:Bias and flats you need, but darks are a bit of a waste of time with DSLRs because the camera is not temperature controlled and so it's very difficult to obtain a valid master dark (the camera will heat up significantly during exposures unless you get rid of the battery and use an external power supply, and even then it still gets warm enough for extra pixels to light up).

ChrisH
Hey Chris, Flats really seem to over run my image when I take them (for Camera only Wide Field) prime focus they work just fine...seems they are really over powering...and you may know this question, Ivo advised me to turn off the (al channel calibration/alignment in DSS) I can't find where to turn this off...I am using DSS 3.3.3 Beta 47. Thanks Chris
It's not easy generating a good set of flats for wide-field (short focal length) camera lenses, flats are supposed to be taken using the same focus setting as the light frames which makes things difficult trying to find a suitable evenly lit background. In the absence of a proper light box a white bedsheet hanging on a washing line a few feet away, lens set at infinity on an overcast day should do it. Might not be perfect but should be a heck of a lot better than no flat at all - and make life easier for removing any remnant gradients during PP.

Not sure what that setting is referring to - perhaps the 'Align RGB Channels in Final Image' check box on the 'Results' tab under the stacking settings? You can try it both ways and see.

ChrisH
I just downloaded the 3.3.4 version, and it seems to be working a little better! I don't know, maybe its just me. I restacked a couple of files and had a little better result. I normally will hold my laptop over the lens of the camera or scope depending on which I'm using at the time with notepad open. I just wonder if I have to place the histogram in a different place. I try to get it about 1/3 of the way to the right of middle. Going to try and get outside again soon and shoot Orion and try for about 1hr and 30 min. this time. thanks again Chris
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