Amy, I appreciate your time for this video, I watched twice how you explained about QE and Full well. I never knew when to use HDR, your example of HDR (left) and Unit (right) really was an eye opener for me as well. I've noted your tip about HDR 0 gain / 50 offset and I'll read through cloudbreak optics. BR - Jeff
Excellent information. I just ordered a ASI183MC Pro and coming from a DSLR I was really confused on gain and offset. Thanks Amy for the great tutorial 🙌🏼
Nice video, Thanks. One thing: I think QE is more about how efficient your sensor is in converting photons to electrons. 40% for example, means that out of 100 photons that hit the sensor, 40 are converted into electrons. I could be wrong but that's what I understand.
EXCELLENT video! Now I can put some sense to all these specs. More important, I have now some testing/evaluation to do with the goal to improve on my techniques and ultimately my images. Respectfully, Henri-Julien, Montreal, QC, Canada
I think you might have got it wron. QE of 60% doesn't mean you can fill 60% of the "bucket". It means your register roughly 60% of photons and convert them to electrons. You can always fill the "bucket" (overexpose), but how much it can be filled is determined by well debth.
Fantastic video Amy, thank you for posting! There are so many technical aspects to what we do, and this video was a great way to explain this topic. Also, the references are great too. Cheers!
Great video, and thanks for the mention of the original source material - it made for a great read. Keep rockin it! And thanks for sharing what you learn in a really easy to understand manner =)
Thanks, Amy. If you drop your offset to 21 from 50, that means that you will have to rebuild a Dark Library and why some will not change the offset. When and if you do, will you take us along for the ride, to see how a typical Library is achieved to save imaging time, please?
Really insightful information Amy Keep up the great video's really helps advance my understanding. Can you consider for one of your upcoming videos filters for OSC cameras specifically around needing to use a CLS and/or UV-IR cut filter
7:03 Quantum efficiency is not a limit of what you can put in the bucket. It is the fraction of photons that are captured. Think of 50% quantum efficiency as meaning that 50% of the photons don't go into the bucket.
Great video Amy! Not sure if this was pointed out but you should look for Dr Robin Glover’s materials also. There is a UA-cam video of him giving a presentation about CMOS imaging. We have the same camera (ZWO1600mm-cool) and I have had this same debate about what settings to use. After everything I’m settling on g139 o50 and more total integration time. Dr Glover explains very well about long vs short exposures. So to your point about the airplanes if you have a CMOS camera, take shorter subs but aim for same total length of time. Clear Sky’s !
Rottie's Rockets & Astrophotography Thank you for the tip. I will look him up. I’ve also settled on the 139/21 lately. So far it works well. It was a good exercise to go through.
Amy, that is a very informative video. My knowledge of Pixel Magic, as I call it, was first "gained" by reading "The Deep-Sky Imaging Primer" by Charles Bracken. He goes into through the the features you reference, plus calibration frames, stretching, and so forth. I would agree that your analogy of buckets and rain drops are well done. If I might provide an observation: pointing to pictures with a mouse arrow is difficult to discern when on smaller tablets, around 8" - 10" or so. Perhaps it would be more effective to reference "the right image" or the "the left image". By the time I found the mouse arrow, the presentation was moving on.
Higher gains are recommended for NB imaging because it helps swamp the noise usually encountered when shooting through narrowband filters. They are very good at blocking photons, especially at low band-widths (3nm for example). A high QE helps mitigate the effects, but I'd always recommend a gain increase, otherwise you could bin the data to increase SNR so long as it doesn't lead to under sampling. You can always drizzle an under sampled image during pre-processing.
Amy, have you used or looked at the camera analysis tool in SharpCap? It supposedly does a full analysis of your camera to give you the "best" exposure time, gain, etc for your camera and sky conditions. I'll see if I can find the video I just watched about it if you've never seen it before. It ties directly to this conversation if I understand it correctly. Btw this is the newb you met at Charlie Elliot with a black eye 😁
Hi Amy, I just got a chance to see this video as I just moved to asi183 from my dslr. I really need to learn gain/offset a bit more and this definitely helps! I found on my imaging software APT where to change gain but I dont see off set anywhere! How do I change off set value? Thank you and clear skies!
Lately I'm hearing that changing the offset is not as critical as it used to be. SGP has eliminated the ability to change this setting also. My images are turning out well without changing the offset value.
Hi...worth checking out is the Sharpcap feature Sensor analysis..once done you can run the Smart histogram and smart brain features...that looks at the sky brightness and suggest setting .. The creator of Sharpcap Robin Glover has some videos on here about it and no subscription needed ..best wishes
Amy, thank you so much for the explanation! Just a curios question... is your night sky Bortle 4 or close to that? I am in the middle of the city with a class Bortle 7 sky, so I am not sure if that is actually even suitable for AP.
Hi Amy, thanks for the video and reference. I found some time ago the following discussion regarding what gain and offset settings are better and why. The information sometimes is way too technical and overwhelming and one of the guys never really understood it but the experts seem to agree to using higher gain values for narrowband processing for several reasons. Link is here... forum.mainsequencesoftware.com/t/added-zwo-settings-dialog/7704
Hi Amy, Hope you don't mind another question, But if you are changing gain and offset, must you also take a new set of flats to compensate? If you change for one channel, the flats would need corresponding settings matching capture settings, or is there a away around this? Thanks, John
John Adastra you really should have all the calibration images match in gain/offset to your actual image. I tried skipping this and ended up with a pixelated mess.
Great way of explaining the concepts of gain, offset, HDR. Superb video and clarity of thoughts
Thank you very much!
Amy, I appreciate your time for this video, I watched twice how you explained about QE and Full well. I never knew when to use HDR, your example of HDR (left) and Unit (right) really was an eye opener for me as well. I've noted your tip about HDR 0 gain / 50 offset and I'll read through cloudbreak optics. BR - Jeff
tonight I'm going to do some tests because of this tutorial, thanks Amy.
:)
I seem to be at Cloudbreak Optics every week for one thing or another. Great place! Very knowledgeble and helpful.
Scott Collier I’m jealous you have a store so close. Drool some for me.
@@AmyAstro And Jon is a great guy, always helps this old guy out with the heavy stuff! Everyone else is great as well!
Excellent information. I just ordered a ASI183MC Pro and coming from a DSLR I was really confused on gain and offset. Thanks Amy for the great tutorial 🙌🏼
Glad it was helpful!
Nice video, Thanks. One thing: I think QE is more about how efficient your sensor is in converting photons to electrons. 40% for example, means that out of 100 photons that hit the sensor, 40 are converted into electrons. I could be wrong but that's what I understand.
Todd Noseworthy I believe you are correct. I did not explain that part well.
Thanks for the update on QE in the description. Awesome work 🔭👏🔥👍
You bet
EXCELLENT video! Now I can put some sense to all these specs. More important, I have now some testing/evaluation to do with the goal to improve on my techniques and ultimately my images. Respectfully, Henri-Julien, Montreal, QC, Canada
Glad it was helpful!
I’m really happy to stumble on this channel. You are one of the best resources I’ve seen and hope to view more.
Thank you so much!
Thanks, I Learned a lot and off to read the articles
I think you might have got it wron. QE of 60% doesn't mean you can fill 60% of the "bucket". It means your register roughly 60% of photons and convert them to electrons. You can always fill the "bucket" (overexpose), but how much it can be filled is determined by well debth.
Thank you for your comment. I will have to do more research.
Fantastic video Amy, thank you for posting! There are so many technical aspects to what we do, and this video was a great way to explain this topic. Also, the references are great too. Cheers!
Glad you enjoyed it!
Very helpful!
Glad it was helpful!
Thanks Amy ! Great video.
Thank you very much.
Spot-On....
Thank you Tom!
Great video Amy, thanks so much!
Thank you!
Greetings from a fellow Deerlick member! Great video!
Hello there! Thank you!
Excellent video Amy, you’ve got me thinking about my settings now..
:)
Great video, and thanks for the mention of the original source material - it made for a great read. Keep rockin it! And thanks for sharing what you learn in a really easy to understand manner =)
Thank you so much! I'm glad you enjoyed it. Made my day.
Great video Amy. Never realized some of thoose numbers on my camera. Gonna read the article.
:)
Thanks, Amy. If you drop your offset to 21 from 50, that means that you will have to rebuild a Dark Library and why some will not change the offset. When and if you do, will you take us along for the ride, to see how a typical Library is achieved to save imaging time, please?
Great Tutorial Video Amy, Thank you for sharing.
Thank you for commenting
Brilliant. Thanks Amy.
Glad you liked it!
Great stuff
Thank you!
Amy , great info. Thanks for sharing.
:)
Thanks!
Nice video Amy. You have a lovely voice !
Thanks for listening
Great info about gain! I always use gain 0 HDR images with RASA 11!
Ray's Astrophotography with that light bucket you don’t need any gain. Lol. Scope envy :)
Really insightful information Amy Keep up the great video's really helps advance my understanding. Can you consider for one of your upcoming videos filters for OSC cameras specifically around needing to use a CLS and/or UV-IR cut filter
I will dig into that and see what I come up with. Thanks for the idea.
Thanks Amy. It was great timing because I'm about to get an astronomy camera. The DSLR was nice but bortle 9 skies is hard to use it.
:)
7:03 Quantum efficiency is not a limit of what you can put in the bucket. It is the fraction of photons that are captured. Think of 50% quantum efficiency as meaning that 50% of the photons don't go into the bucket.
Great video Amy! Not sure if this was pointed out but you should look for Dr Robin Glover’s materials also. There is a UA-cam video of him giving a presentation about CMOS imaging. We have the same camera (ZWO1600mm-cool) and I have had this same debate about what settings to use. After everything I’m settling on g139 o50 and more total integration time. Dr Glover explains very well about long vs short exposures. So to your point about the airplanes if you have a CMOS camera, take shorter subs but aim for same total length of time. Clear Sky’s !
Rottie's Rockets & Astrophotography Thank you for the tip. I will look him up. I’ve also settled on the 139/21 lately. So far it works well. It was a good exercise to go through.
Amy, that is a very informative video. My knowledge of Pixel Magic, as I call it, was first "gained" by reading "The Deep-Sky Imaging Primer" by Charles Bracken. He goes into through the the features you reference, plus calibration frames, stretching, and so forth. I would agree that your analogy of buckets and rain drops are well done. If I might provide an observation: pointing to pictures with a mouse arrow is difficult to discern when on smaller tablets, around 8" - 10" or so. Perhaps it would be more effective to reference "the right image" or the "the left image". By the time I found the mouse arrow, the presentation was moving on.
Excellent feed back. Thank you!
Higher gains are recommended for NB imaging because it helps swamp the noise usually encountered when shooting through narrowband filters. They are very good at blocking photons, especially at low band-widths (3nm for example). A high QE helps mitigate the effects, but I'd always recommend a gain increase, otherwise you could bin the data to increase SNR so long as it doesn't lead to under sampling. You can always drizzle an under sampled image during pre-processing.
Good info, Thanks!
:)
Amy, have you used or looked at the camera analysis tool in SharpCap? It supposedly does a full analysis of your camera to give you the "best" exposure time, gain, etc for your camera and sky conditions. I'll see if I can find the video I just watched about it if you've never seen it before. It ties directly to this conversation if I understand it correctly. Btw this is the newb you met at Charlie Elliot with a black eye 😁
Polar Blind I remember, I have not used Sharpcap yet. Sounds like a great feature
can you turn up the volume
Hi Amy, I just got a chance to see this video as I just moved to asi183 from my dslr. I really need to learn gain/offset a bit more and this definitely helps! I found on my imaging software APT where to change gain but I dont see off set anywhere!
How do I change off set value?
Thank you and clear skies!
Lately I'm hearing that changing the offset is not as critical as it used to be. SGP has eliminated the ability to change this setting also. My images are turning out well without changing the offset value.
Nes....one well can collect 100% of drops but only the 60% of incoming drops....
Hi...worth checking out is the Sharpcap feature Sensor analysis..once done you can run the Smart histogram and smart brain features...that looks at the sky brightness and suggest setting ..
The creator of Sharpcap Robin Glover has some videos on here about it and no subscription needed ..best wishes
Thank you, I recently purchased SharpCap, just no clear sky to give it a go. I will look for the feature.
Amy, thank you so much for the explanation! Just a curios question... is your night sky Bortle 4 or close to that? I am in the middle of the city with a class Bortle 7 sky, so I am not sure if that is actually even suitable for AP.
My last house was bortle 6/7 so yes you can image! You just need to consider filters. Like an L-Enhance, Tri-band, or and LProMax.
@@AmyAstro thank you so much for your response! I’ll give that a try!!
Hi Amy, thanks for the video and reference. I found some time ago the following discussion regarding what gain and offset settings are better and why. The information sometimes is way too technical and overwhelming and one of the guys never really understood it but the experts seem to agree to using higher gain values for narrowband processing for several reasons. Link is here... forum.mainsequencesoftware.com/t/added-zwo-settings-dialog/7704
Thanks for the link, I will check it out.
Hi Amy, Hope you don't mind another question, But if you are changing gain and offset, must you also take a new set of flats to compensate? If you change for one channel, the flats would need corresponding settings matching capture settings, or is there a away around this?
Thanks,
John
John Adastra you really should have all the calibration images match in gain/offset to your actual image. I tried skipping this and ended up with a pixelated mess.
Amy but if i am not mistaken the higher the gain the less is the noise right?we have to find the right balance i think?
Davide Mancini not really. Check out the article on cloud break optics. The author explains them better than I can.
Made it so simple, they should get you to write manuals.
lol Only if I can add emojis to the pages.
FYI. If you zoom in on an image in PI, you can drag the tab and drop it onto your 2nd image's tab, and PI will match them exactly.
Really? I will give it a try. Thank you!!