ZWO asi585mc Pro vs asi533mc Pro

[BlurredClarity (Manesh)]

Hi there.

I currently have the asi2600mc pro camera with the Redcat 51, Zenithstar 73 and looking to purchase the ASKAR 80PHQ also.

I was hoping to get another camera that can give me a bit more reach and was looking at these two.

I am relatively new to DSO photography and haven't full learnt the terminology about what is best suited for each camera etc so bear with me please.

I have read so far that the 585 is the newer camera but the 533 performs better. I know the 585 gives me a bit more reach but not sure it's worth it at the cost of the quality (from what i read).

What would you recommend out of the two?

I also use the am3 and the asiair plus.

Thanks in advance.

[Camelopardalis (Dunk)]

They’re the same technological generation. Any differences between the two are marginal at most.

It’s more a question of whether you prefer the square or the widescreen format.

[BlurredClarity (Manesh)]

Originally Posted by Camelopardalis

They’re the same technological generation. Any differences between the two are marginal at most.

It’s more a question of whether you prefer the square or the widescreen format.

Yeah i don't mind the square personally. If they are that close that it doesn't matter then I might go with the a533.

One thing I just read up was that the a585 is 12 bit and the a533 is 14 bit which I also prefer.

Thanks for the info.

[Camelopardalis (Dunk)]

I hate to burst your bubble, but that is not one of the factors that makes the 533 preferable mathematically.

[rmuhlack (Richard)]

the asi533 hits unity gain (1 e-/ADU) when the camera gain is at 100. that is also the camera gain where the HCG mode kicks in, so read noise at that setting is <1.5 e-. the full well at that setting is ~16000 e-

for the asi585, when the camera is at unity gain, the read noise is still at about 3.8. low read noise (of about 1.1 e-) doesn't kick in until camera gain is at 250, and at that setting the full well is only about 2500 e-

so the 533 has more dynamic range, deeper full well and lower read noise at the settings you'd want to be using. the 533 also has bigger pixels (3.76 microns, compared with 2.9 microns), so will offer more sensitivity than the 585 (at the expense of resolution) if comparing both sensors on the same optic.

finally the dark noise of the 533 is about one quarter that of the 585.

all together, the 533 has more dynamic range, deeper full well and is less noisy than the 585. if the optics are fixed, the 533 will be more sensitive than the 585 (even when the QE of both sensors is factored in), albeit at a slightly lower resolution.

(disclaimer - I own the QHY version of the 533C)