So, my nice new ASI2600 arrived yesterday so I thought I would put up some very initial impressions.
Firstly it is noticeably bigger and heavier than the ASI294MC Pro, no longer a Coke can. The unit comes shipped with the normal long ribbon USB3 cable and short USB2 cable to connect a focuser or similar to the hub, now with a right angle connector for the hub end which might be useful cable management wise, more to come there. It comes fitted with a nice screw in M42 blanking plug fitted in the hole in the tilt plate and the extensions come with a suitable cap to replace that.
With the current drivers loaded, detection of the camera via Voyager was seamless using the native driver, I set it up to shoot at the gain I hope to use most commonly ("Unity" gain, which is a little over that in fact, as far as I know and provides about 4e read noise with 51Ke full well)
It is now shooting a full dark library on the desk, cooled to -10 while I await me new mount and some spacers for setup on the scope. A quick comparison below of a 50 frame X 300 second master dark with my ASI294 and a 47 frame 300 second master dark (That is all the frames it has shot at 300 seconds so far) from the 2600, I will leave it to the reader to guess which is which!
It is now shooting a full dark library on the desk, cooled to -10 while I await me new mount and some spacers for setup on the scope. A quick comparison below of a 50 frame X 300 second master dark with my ASI294 and a 47 frame 300 second master dark (That is all the frames it has shot at 300 seconds so far) from the 2600, I will leave it to the reader to guess which is which!
I am looking forward to first light.
All I can say is Holy f#$K! That is a massive difference. I wonder how the 071 MC Pro (which should be coming soon hopefully) compares.
Pretty huge difference yeah, to be fair though the glows int he ASI294 do calibrate out fine, I am hoping through that the weird rectangular colour cast that does not seem to be able to be calibrated out in the 294 does not make an appearance. With good darks and flats you did need to stretch the data hard to see it, but it limited the target selection as it showed up the most on dark backgrounds.
I passed the 294 on to my 12 year old, it will be a long while before that sort of "Last gasp" calibration issue bothers him.
Less great news is that you've given your 294 to your son... I was just about to make my run at that
So your son now has the old (AZEQ6?) mount and the 294... I'm keen to see how he gets on with it all! I have a 9yo daughter who is super keen on imaging, and tis impressive to see how much she remembers of the set up and imaging procedures each time we get the gear out.
Yeah, I have basically gifted him the entire old imaging rig, just with the SCT I used to use instead of my flash and shiny SVX80T. If he maintains the interest we will see about a more imaging friendly OTA down the track, whicle keeping it within the useful abilities of the AZEQ6, maybe a Edge HD 8" or similar to get a much nicer and flatter field than the vanilla SCT with flattener.
Paul there is an interesting discussion on Cloudy nights..something about tilt..just goggle it will appear.
I was thinking about one so I look forward to hear your updates.
Alex
Paul
Here’s what a member on the APT forum mentioned to me in regard to gain on the 2600MC
“The 2600MC has no Unity gain due to its 16bit ADC. The most used setting for gain is 0 (max dynamic range due to best use of full well capacity) and 100 for low read noise , refer to ZWO specs.
When shooting under dark skies go for a longer exposure and use gain 0.
In suburban skies shoot shorter exposures and use gain 100 to reduce read noise
Your thoughts on the above comments would be appreciated
Martin
That is more or less my understanding too. “Unity” gain and “Highest dynamic range” in the driver pull down list are the same thing. I believe that gain 0 is about 0.8e/ADU so as close to unity as they go.
Edit to add, I was on my phone before. I hope and expect to use gain 0 in my application to hopefully get the best star colours out of it. I am not actually sure that the gain level will make much difference with respect to dark skies as I have or under light pollution. The only advantage I could see is that the lower read noise would let you overcome the read noise sooner, allowing you to use more but shorter exposures.
Last edited by The_bluester; 29-07-2020 at 11:47 AM.
That is more or less my understanding too. “Unity” gain and “Highest dynamic range” in the driver pull down list are the same thing. I believe that gain 0 is about 0.8e/ADU so as close to unity as they go.
Edit to add, I was on my phone before. I hope and expect to use gain 0 in my application to hopefully get the best star colours out of it. I am not actually sure that the gain level will make much difference with respect to dark skies as I have or under light pollution. The only advantage I could see is that the lower read noise would let you overcome the read noise sooner, allowing you to use more but shorter exposures.
Congrats on your new camera it's certainly an interesting new entry into the market.
It'd be interesting to see if there's any discernible difference between gain 0 and gain 100 when it comes to star colours. Where the HCG kicks in at gain 100 yields almost the same dynamic range as gain 0...from ZWO's plot, it looks like it loses about half a stop, and it's almost 14 stops at gain 0, so pretty impressive.
And I'd estimate your exposure time at gain 100 to be roughly 40% of exposures at gain 0.
Yeah, I can foresee a bit of experimentation in my future with regard to low gain and longer exposure versus higher gain and shorter subs.
That said, my biggest gripe with the ASI294 was blown out brighter stars due to the limited full well capacity at the gain where the HGC mode kicked in (One step above unity) Using the lowest gain on that camera produced a lumpy, mottled sort of result.
The darks of the ASI2600 look as smooth as the example I put up above at 30, 60, 120, 300 and 600 second exposures and lowest gain, it is hard to tell them apart visually in fact where the difference is obvious with the 294. I am hoping to be able to use the lowest gain and longer exposures to trap a few more photons, while at least keeping the star colours as good as they are out of the 294. Time will tell. The read noise of the 2600 at worst is about half of the worst of the 294, it's worst in fact is only about double the best of the 294. Higher gain for better read noise looses a bit of punch in the debate when the worst gain is 3.3e.