Zwo Asi294mc High Speed Mode

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Tiago Ferreira
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Joined: Sun Mar 21, 2021 10:50 pm

Zwo Asi294mc High Speed Mode

#1

Post by Tiago Ferreira »

I searched a lot but never managed to understand this feature.

From the manual:

"May improve the frame rate under some circumstances. Changes from using the 12bit ADC on the camera to using a 10bit ADC. Enabling high speed mode may increase image noise when the gain is set to a low value."

Well, as i know nothing about ADC and bits, from my tests with both ZWO 224mc and ZWO 294mc i've noted that on the smaller sensor zwo224 the high speed mode ON returns plenty of noise to the image so i use it OFF mode.
But this doesn't happen in my zwo294 and i have it ON just because it can handle it. But i would like to know the pros and cons of having it ON with this camera. Should i use it ON or OFF and why?
In case i change to OFF mode should i get new darks?
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Re: Zwo Asi294mc High Speed Mode

#2

Post by admin »

Hi,

if you change a control like that which affects the image data then you definitely need to do new darks otherwise they will not match.

I think the best guidance is that if you are using exposures longer than about 0.1s then this should be firmly set to 'off' and left that way. Using this mode may get you higher frame rates which can be useful sometimes in lunar/solar/planetary imaging, but it's not going to help at all in deep sky work - if you are using a dark frame it's a good sign that you don't need this turned on!

cheers,

Robin
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