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Image Capture Frame numbers

Tracy

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When obtaining captures with a mono camera, do you take the same number of frames for each filter?
Or do you take fewer frames for say luminance and then more for the RGB and then a different amount for narrowband?
What have you found to be the best process? And yes, I do plan to also get a color camera in the future... but understand that under current technology that the mono camera tends to provide the better imagery.
 

OhNo

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I would normally urge someone new to AP to start with a Color camera. The simplicity of OSC imaging allows the user to become familiar with all their gear and their capture software of choice. It is somewhat true that a mono camera will give a more highly defined image, the new color cameras do a great job. The term used to describe the difference between a color cam and a mono one is "Pixel Picking" IMO.

Nothing is more of a hobby killer than failure. It is difficult enough for people especially urban people to capture good data. There are a lot of filters available now that can make data acquisition in a urban light polluted enviornment less painful. The term "can't make a silk purse out of a sows ear" applies here. If the data sucks processing is challenging if not impossible. Both OSC and Mono images require processing.

In regards to your question about number of exposures for each filter. There are a lot of opinions on that issue. The more nice clean data you can acquire will give you better Signal to Noise Ratio (SNR). I may be wrong, but I look at SNR as resolution or vividness. I would star capturing equal amount of total exposure data for each filter. Again processing programs will come to play in this issue. One option that can be used is to use pixel math to utilize a ratio of each filter in the whole image. The only limitation is the time someone wants to spend of getting the most out of their data to make the image look like the person doing it wants.
 

Stan

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There are many different ways to shoot LRGB with a mono camera. Here I have a 2.5 to 1 ratio of Luminance to RGB, the luminance helps bring out more details. I have 75-120 second of Lum & 30-120second of each RGB. There is no way set in stone
 

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OhNo

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Stan, you run some of High end filters. Are they fairly consistent when it comes to focus?
 

Tracy

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William Optics 103mm
Celestron NexStar 8SE


Stan, you run some of High end filters. Are they fairly consistent when it comes to focus?
Not Stan... but amazingly I found that (using the Bahtinov mask) that every one of the ZWO filters in my wheel used the same focal point. I was really surprised. At first, I thought there was some difference, but realized that I had taken a break and the outside temp dropped by about 12 degrees and when I went back and looked at the filters I had already checked, they were also out of focus at the setting they were in focus at earlier... but when I used the focus for the O-III (the first one I noticed a difference on) they were fine at that time.
 

OhNo

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Yup, my bargain basement ZWO LRGB filters are close enough (individual choice for maximum HFR or FWHM difference) that I don't need to re-focus after a filter change. I am not as lucky with my Narrow Band filters.

I have found that if I initiate the autofocus and set it to do a re-focus if the temp changes more than 3C works the best for me.
 

Stan

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I use the Antila LRGB Pro filters & 3.0 Nm narrowband filters, the filters are very close to parfocal but sky conditions are more of an issue. I run NINA for capture & have been using filter offsets which is a time saver when shooting LRGB, also i have autofocus runs set if HFR changes more than 6%
 
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