Artificial light source or natural for sensor analysis?

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Bikerdib
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Joined: Tue Dec 19, 2017 3:21 am

Artificial light source or natural for sensor analysis?

#1

Post by Bikerdib »

Just joined the forum and I'm pretty new to AP. In fact, I do what I consider a cross between NRTV and actual AP. I am not opposed to doing longer subs if it can bring out more detail but I don't do any real post processing to saved images, just some color adjustment and contrast/brightness fine tuning. I may try using Autostakart in the future to post stack some saved individual fits files but so far I just do live stacking then saving the image.

I am wanting to use the sensor analysis feature but from what I've read on CN forum, it is supposed to be better to use natural light (diffused sunlight). I would like to do the analysis on my ASI224MC cool and QHY163 color cameras but have been under clouds for several days so it would give me something to do at night. Is light from a tungsten light bulb OK? My plan is to use a white plastic eyepiece barrel cap and maybe a white cloth till I get the correct amount of light on the sensor for whatever light source I use.

Also, I recently upgraded by buying the Pro license, any idea when 3.1 will be ready for general release?
Bikerdib
Posts: 19
Joined: Tue Dec 19, 2017 3:21 am

Re: Artificial light source or natural for sensor analysis?

#2

Post by Bikerdib »

LOL, I guess I was really tired when I wroth the first post. I meant to say incandescent light bulb not tungsten.
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admin
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Re: Artificial light source or natural for sensor analysis?

#3

Post by admin »

Hi,

here's what you need to know on light sources for sensor analysis - they need to be as steady as possible!

That means:

Daylight on a clear day with no clouds is good
Daylight on an overcast day with uniform cloud is good
Daylight on a partly cloudy day with clouds coming and going is bad as it could change during the measurement

Indoor lights are OK, as long as you are not seeing too much flicker. If you are seeing bands in the image at short exposure due to the flicker of indoor lights then making the selection area tall so that it covers several bands will help a lot.

When will 3.1 be released? I'm hoping around the end of the year or early in the new year. I have a fairly short list of things I want to finish off and then of course any bugs...

cheers,

Robin
Bikerdib
Posts: 19
Joined: Tue Dec 19, 2017 3:21 am

Re: Artificial light source or natural for sensor analysis?

#4

Post by Bikerdib »

Thanks Robin, keep up the fantastic work. I'm sure most users are as highly grateful as I am. That's one reason I went ahead and upgraded to pro.
Bikerdib
Posts: 19
Joined: Tue Dec 19, 2017 3:21 am

Re: Artificial light source or natural for sensor analysis?

#5

Post by Bikerdib »

Thanks for the heads up about the issue of light flicker. I'm going to utilize my deep cycle battery that I use to power the mount and a 12 volt light which will eliminate the flicker issue from the man made light source. It's supposed to be cloudy again tonight so I'll at least be able to do this.
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Re: Artificial light source or natural for sensor analysis?

#6

Post by admin »

Hi,

yes, a battery powered light should do the trick with no flicker. Don't forget to analyze both the RAW8 and RAW16 modes on each camera as that means that the full sensor data is available to SharpCap.

The QHY cameras typically have a very wide gain range - this can make choosing the initial brightness trickier than other cameras - SharpCap also chops off some of the top of the gain range on some QHY cameras as it is just excessively large and not really suited to deep sky.

cheers,

Robin
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