Exposure time recommendations for my setup

It also depends on the target you are shooting and how many large stars might get saturated.  I have a Redcat 71 with a 2600MC camera and I sometimes use 180s with no filters.  I usually do test frames to see if I am happy with the results before I commit to a whole night of shooting.

Thank you for the reply.

It makes sense that exposure times will vary as I image different targets. Unfortunately, on my Bortle 8 balcony 180s without a filter is just too much. Even 60 seconds was too much.
Also, without a filter I can more obviously see when Im overexposed, but with the filter its not so obvious to me. Do you have any tips/advice to help me notice that i should lower my exposure time? I obviously want to gather as much data from the fainter stars/nebulosity, but at the same time I dont want to go too far.

Sam Badcock:
I’m under bortle 4 skies and predominantly shoot narrowband with a 2600MM but even when doing LRGB I’ll shoot 300s exposures unless it’s a very bright target (Orion for example) then I’ll spend an hour shooting RGB at 20seconds purely for unsaturated Stars then combine in post!!

Gaetano R. Cassarino:
Hi guys! I usually shoot from a 7/8 bottle sky in my home town and also from a bottle 4 sky (mostly in the weekend). I use both a Asi2600MM and a 294MC. I might say I always try to shoot at 600" and never got a saturated nebula, then as Sam Badcock said I took some lower exposure on the stars...depending on the target this may change from 1s up to 180s. Same thing when you try to make some HDR on Orion or a Galaxy core for example. As for the Gain I mainly use the unit gain or gain 0.
I shoot 600" for two main reason: increasing the SNR, but also to minimize the number of picture I have to process (my laptop isn't exactly brand new ). So as far as your mount works, try to increase the exposure!

Gaetano R. Cassarino:
I took 600" subs also with my EQM-35 mount. So your AM5 will definitely work. Just be sure to balance well your setup and also polar align the best you can.

Luigi Ferrari:

Luigi Ferrari:
Anch’io faccio riprese da un cielo bortle 7/8 e uso un Newton 250/1000, Asi 294 MC pro con Antlia Quad Band, arrivo tranquillamente a 300 secondi di esposizione, naturalmente con una buona autoguida, se no puoi avere le stelle strisciate.. dipende comunque molto dal soggetto che vuoi riprendere… con tempi lunghi guadagni più qualità nell’immagine, miglior rapporto segnale/rumore, devi lavorare sul gain (portandolo anche a zero se serve) controllando l’istogramma che vedi sull’asiair plus..

Thank you for the reply.

I will definitely try lowering the gain and going for longer exposures to compare the images with what Im doing now.
At what gain do you shoot when taking 300 second exposures with the setup you mentioned?

Io con galassie o ammassi stellari molto luminosi a 0 gain, invece con galassie meno luminose o nebulose sui 120-180 di gain.. però devi considerare che il mio telescopio ha un buon guadagno in luminosità, essendo un 250 mm. di diametro… devi comunque avere pazienza e fare tante prove, come ho fatto io..

Arun H:

Joe Linington:
This thread is killing me. Disregard any answer from anyone who doesn't image with your exact camera or very similar. The ASI585MC Pro has one of the smallest well depths of any camera released in the last 5 years.

the small well depth is likely because it has small pixel area. Comparing pixel full well capacities should normalize for pixel area. A smaller pixel area at fixed photon flux obviously means fewer incident photons.

Joe Linington:

Arun H:

Joe Linington:
This thread is killing me. Disregard any answer from anyone who doesn't image with your exact camera or very similar. The ASI585MC Pro has one of the smallest well depths of any camera released in the last 5 years.

the small well depth is likely because it has small pixel area. Comparing pixel full well capacities should normalize for pixel area. A smaller pixel area at fixed photon flux obviously means fewer incident photons.

The tiny well depth is a result of a 12bit DAC (which becomes the limiting factor, not the sensor) and the fact that ZWO placed the HCG nowhere near unity gain. It is a common criticism of the ZWO version of the 585 and others like QHY, ToupTek and Player One didn't make the same mistake. At gain 252 which is the HCG crossover the well depth for the ZWO 585 cameras is 2048. In other versions it is double that but the OP already has the ASI585MC Pro so he has to learn what he's got. I have the SVBony 705C and QHY5III585M and they are both setup like the ASI camera which is a setup more for planetary and EAA and not DSO.

In short, this particular camera does not normalize due to pixel size like you would expect. It is artificially limited to less than half the normalized well depth when compared to a 294 or 571 sensor.

Tony Gondola:

Joe Linington:
This thread is killing me. Disregard any answer from anyone who doesn't image with your exact camera or very similar. The ASI585MC Pro has one of the smallest well depths of any camera released in the last 5 years. It's also very noisy below gain 252. Most of the guys above have either 294 or 571 cameras which are totally different (I have them as well). The very best way to figure out the 585 is by monitoring saturated pixels. This number tells you  how close you are to blowing out the stars. This is by far the limiting factor with a 585 sensor, especially the ASI version. Unfortunately the ASIAir doesn't give you this number. With my 585 camera which is setup the same as yours, I use gain 252 and subs between 60s and 120s depending on the speed of the scope. 60s is best on my f/4 newt and f/4.5 refractor, 90s for my f/5.6 scope and 120s at f/7. If I use a dual NB filter (10nm or less) then I use 180s-300s. Always gain 252. Your quad band filter shouldn't change these numbers much if at all. It's all about the stars with this sensor.

Hope this helps.

This is a 585, 60s subs with my f/4 Newt. I have dark skies so just a UV/IR filter.

I totally agree with Joe on this. I've been shooting with a 585 for a few years now and have found that the two best settings for me are a gain of zero when I really need to maximize the dynamic range and 255 which puts the camera in a mode where read noise goes down to practically nothing. I shoot with an F/6 Newtonian and am under bortel 8 skies. My basic exposure time for deep sky objects with no filter or with a UV/IR cut are 15 sec. In dual band I'll go 30 to 60 sec, depending on the target. In all cases my biggest source of noise is shot noise from the high degree of light pollution and not the noise from the camera. The best thing to do is just get out there and shoot but hopefully those numbers give you a good starting point.

Joe Linington:

Arun H:

Joe Linington:
This thread is killing me. Disregard any answer from anyone who doesn't image with your exact camera or very similar. The ASI585MC Pro has one of the smallest well depths of any camera released in the last 5 years.

the small well depth is likely because it has small pixel area. Comparing pixel full well capacities should normalize for pixel area. A smaller pixel area at fixed photon flux obviously means fewer incident photons.

The tiny well depth is a result of a 12bit DAC (which becomes the limiting factor, not the sensor) and the fact that ZWO placed the HCG nowhere near unity gain. It is a common criticism of the ZWO version of the 585 and others like QHY, ToupTek and Player One didn't make the same mistake. At gain 252 which is the HCG crossover the well depth for the ZWO 585 cameras is 2048. In other versions it is double that but the OP already has the ASI585MC Pro so he has to learn what he's got. I have the SVBony 705C and QHY5III585M and they are both setup like the ASI camera which is a setup more for planetary and EAA and not DSO.

In

Tony Gondola:
I mostly use 255 as my default 90% of the time. I'll only go to zero gain if I'm trying to get a very bright galaxy core or I want to resolve a globular right to the core. Lunar too but that's a totally different subject. I will say that worry about well depth is overblown as long as your exposures arn't too long which they won't be on the 585. I've gone as low as 1500 (e-) on a QHY camera I it was fine, at least at 15 sec. Remember that your final image will be 8 bit, 256 shades of gray so you have more headroom than you think. It's another area where not going too long helps.

Thank you for the reply.

I will keep that in mind, thank you.

I checked out your gallery of images and I must say your work is amazing. Seeing what you accomplished with the same camera made me realize I still have a lot to learn and improve on.