UPDATE FROM MABULA
I have had a very rough 2 months unfortunately health wise. I was struck 3x in a row with bacterial infections. The second infection occurred after a routine hospital checkup and I became very sick. I had to rest and take a lot of antibiotics. Once I was recovering and restarting work 1 month ago, I again became sick. The infection was not yet gone, so even more antibiotics and rest was needed. Needless to say, it took a lot of my energy and I needed a lot of rest.
Finally, the infection is really gone and my energy is coming back step-by-step now and I have started work again. I am terribly sorry to have kept you waiting for support. I will address all outstanding questions and e-mails step-by step and will be on the forum daily from today.
APP 2.0.0-beta47 will come soon as well, a lot of work was already completed before I became very ill, so the release is also nearly ready for you. Beta47 will be much faster actually. Many workflows will be more than 2x faster, mosaics can even be 10x faster than before because registration really received a major boost... all compared to beta46. Before I release it, I will make sure that everything is working properly and then I will release it.
I am thinking of upgrading from an Ha-modified T3i to a dedicated astrocam. But, I would like to better understand what this buys me in the final image. I shoot in mostly B7+ skies and stack in Astro Pixel Processor. APP’s SNR per RGB channel typically is 1-2 dB.
If I move to a dedicated astrocam, how much of an increase in SNR can I expect? Example below compares the Full Well Capacity and Read Noise of my T3i to the SvBony 405cc.
FWC RN. Dynamic Range (FWC/RN)
T3i. 21Ke. 2.9e. 7200
SV405 63Ke. 1.2e.
The SvBony is 3x better at FWC, and about 2.5x better RN. Does this translate to an SNR increase of about 5dB? I know I will have improved dynamic range, but does that also lead to SNR improvement? Light pollution really limits what I can cleanly process.
Thanks in Advance!
Edited by martinontheroad,
Hi Martin @martinontheroad,
Thank you very much for your question.
First of all, SNR or Signal to Noise Ratio can be reported in a lot of different ways. We do not report it in decibel or dB. We simply report the signal to noise ratio, so Signal divided by Noise or Signal/Noise. This way was thought to me by during my astrophysics studies. We hardly used the dB notation.
See here for more explanation: https://en.wikipedia.org/wiki/Signal-to-noise_ratio
Decibel is logarithmic. Our SNR value is linear. So SNR of 10 in APP is 10x better than SNR of 1 in APP. For me, this is much more intuitive than using Decibel for SNR. Decibel is better with huge dynamic range between signal and noise...
Now, regarding your question, this is very hard to give you a good answer, because the resulting SNR depends on many aspects not relating to your camera's sensor. Like the object itself that you image, or the sky conditions.
You indicate that the SvBony is 3x better at full well capacity, meaning the pixels can collect much more photons before being saturated and the read noise is 2,5 better... but for the astrocamera, this depends on the gain which you use of course. Depending on the gain the FWC changes as well...
Generally speaking, I would expect the SvBony to outperfrom the T3i clearly with the bigger wells and lower read noise in general. I would advise you to use low gain with the SvBony and longer exposures when compared to exposure times with your T3i as well to use the well capacity 😉
How this will translate to typical SNR with your results with the SvBony is still hard to tell because we have many other noise factors, like the dark current of the sensors and the shot noise of the signal, so it is not a simpel calculation. The amount of dithering between your subs will also influence the SNR of your integrations... but I would certainly expect the SNR will be better with the SvBony 😉 and you will clearly see this visually in your results.
Mabula
