12 replies to this topic

[mhevey]

Had some clear skies after a long run of bad weather and was able to get out and capture some photons. This is 3.5 hours of 60 second exposures of M13 with an ASI2600MC Pro attached to an Esprit 100. Image was taken from a bortle 5 zone. Critiques welcome. A higher resolution image can be seen at  https://www.astrobin.com/6gudes/B/

 

 

 

[bobzeq25]

Excellent.

[michael68]

Just.. wow!

[RogerM]

That is one beautiful image!

[jpengstrom]

Beautiful image!  Great sharpness and well done with the star colors.  Bravo!

[mhevey]

Thank you all! I am pretty happy with the imaging rig I have but am still working on the processing side of things using pixinsight.(such a steep learning curve but lots of great resources out there).  Just finished another project (M101 Pinwheel Galaxy) in which I was able to get over 12 hours of integration. 

 

[smiller]

Great shot!

 

I’m just starting out and also have a one shot color camera.  Can you say a little bit about how you decide to set exposure and gain to get the most stars yet retain the color and not oversaturate?   What should my subs look like to strike this balance on a globular cluster like in M13?

 

 

Thanks,

 

Steven

 

 

[davebuechler]

Very nice!

[gabebalazs]

Excellent capture!

[Oort Cloud]

Textbook!

[mhevey]

Great shot!

 

I’m just starting out and also have a one shot color camera.  Can you say a little bit about how you decide to set exposure and gain to get the most stars yet retain the color and not oversaturate?   What should my subs look like to strike this balance on a globular cluster like in M13?

 

 

Thanks,

 

Steven

Thank you Steven. 

 

In terms of the OCS camera, I have the ASI2600mc pro and for that specific camera tend to shoot at 100 gain and an offset of 50. I am not an expert, but here is the rationale I have used for the gain. At gain 100 the read noise drops significantly according to ZWO and dynamic range is mostly recovered. I have found it is good for shorter subs in suburban skies where I am imaging. The full well drops from about 50K to 20K but with the shorter subs that hasn't been issue (If you're in a dark sky, you can set the Gain to 0 to maximize bit depth, and full well capacity for longer subs).  I haven't tried gain 0 on brighter objects (like the M13 cluster) since I don't get over saturation of the stars, but if I were over saturating the stars then the additional full well at gain 0 would help (just haven't needed to go there as this camera has been very impressive).  The offset is just set to the default and what I have seen others shoot with, and have not experimented with that as I have been satisfied with the results I am getting at an offset of 50. Those numbers all hold true for the ASI2600MC pro or other OSC cameras with the imx571 sensor. If you have a camera with a different sensor, then the gain and offset would be different and based off the performance of the chip. There are a number of videos on YouTube such as Robin Glover's videos on choosing the right gain for deep sky imaging with CMOS cameras (https://www.youtube....h?v=ub1HjvlCJ5Y)

Edited by mhevey, Today, 01:56 PM.

[Oort Cloud]

Thank you Steven.

In terms of the OCS camera, I have the ASI2600mc pro and for that specific camera tend to shoot at 100 gain and an offset of 50. I am not an expert, but here is the rationale I have used for the gain. At gain 100 the read noise drops significantly according to ZWO and dynamic range is mostly recovered. I have found it is good for shorter subs in suburban skies where I am imaging. The full well drops from about 50K to 20K but with the shorter subs that hasn't been issue (If you're in a dark sky, you can set the Gain to 0 to maximize bit depth, and full well capacity for longer subs). I haven't tried gain 0 on brighter objects (like the M13 cluster) since I don't get over saturation of the stars, but if I were over saturating the stars then the additional full well at gain 0 would help (just haven't needed to go there as this camera has been very impressive). The offset is just set to the default and what I have seen others shoot with, and have not experimented with that as I have been satisfied with the results I am getting at an offset of 50. Those numbers all hold true for the ASI2600MC pro or other OSC cameras with the imx455 sensor. If you have a camera with a different sensor, then the gain and offset would be different and based off the performance of the chip. There are a number of videos on YouTube such as Robin Glover's videos on choosing the right gain for deep sky imaging with CMOS cameras (https://www.youtube....h?v=ub1HjvlCJ5Y)

IMX455 is from the 6200; the 2600 is based off of the IMX571.

[mhevey]

IMX455 is from the 6200; the 2600 is based off of the IMX571.

Thanks, I stand corrected and updated the post