Using a ADC

[StargazingAde]

Hi there,

I am new to the forum and have a Omegon ADC and a ASI290 on a CPC1100. The seeing has never been that good when I have used the ADC but which side should the  levers be? is it on the left or the right when set up?. If the levers are set up so they are on the left, when adjusted the image moves down which I always thought would be correct because I have always believed that objects always look higher than they are - is this right?

[Cosmic Geoff]

The image moves when I adjust the levers in my ZWO ADC.  Nothing to do with the atmosphere affecting the apparent height - it's something to do with the prisms.

Which side do the levers go on? Whichever way gets rid of the colour dispersion.

[inFINNity Deck]

Hi Ade (is that your name?),

I use a ZWO ADC and the levers are normally to the right of of it. Before mounting the ADC, move the levers into the same direction and symmetrical within their combined slits. Adjust the vial so that in that position the levers are horizontal. Then mount the ADC and turn it to make the vial level.

Once level and mounted I adjust my ADC using ZWO's ASICAP (click on the ADC icon within the image). There is also a tool for it in FireCapture, but that has a flaw. In FireCapture the calculated offsets vary with the position of the planet on the imaging chip, something that should not happen. In ASICAP the calculated offset are independent from the planet's position as it should. This difference makes it almost impossible to use FireCapture to adjust the ADC (for me at least). Sometimes, especially at low altitude, it may become difficult the get the right ADC setting. Adding additional length between ADC and camera helps in those cases (I added 40mm for that).

So I adjust in ASICAP, then switch to FireCapture to get my imaging done. When shooting monochrome, I first mount a colour camera to adjust the ADC, the replace it with the monochrome camera, start FireCapture and do some imaging. The reason for this is, that within the RGB-filter's bandwidth the light still gets deflected, so even when shooting monochrome the ADC does help.

HTH

Nicolàs

PS: when adjusting the levers, the planet moves over the imaging chip, that is indeed normal behaviour. For this it helps to have a guide scope that can easily be adjusted.

Edited June 28, 2020 by inFINNity Deck

[StargazingAde]

Hi Nicolàs and Geoff,

thanks for the information. I have been struggling to get the correct set up information - even the information from the manufacture didn't make sense because there information sheet showed the adjustment levers on the right and level with the horizon BUT during the conversation they said to set it up so the levers / neutral mark pointed vertical from the horizon which meant the correction would be in the horizontal and not vertical!. 

[CraigT82]

The null position of the levers should be parallel with the horizon as seen through the scope.

 On my ZWO ADC I have the levers on the right hand side, however earlier versions needed to be on the left hand side I believe.  See this CN thread... there is a very useful test to determine wheter you have a left or right handed ADC.

 

https://www.cloudynights.com/topic/525563-for-users-of-the-new-zwo-adc-important/

Edited June 30, 2020 by CraigT82

[StargazingAde]

Hi Craig, 

well just used the test and the correction is better with the levers on the left-hand side so my Omegon ADC must be a left hander!. As you adjust the prisms, the image moves downwards and the definition of the circle edge becomes much  more defined.

also thinking back, I once attached the camera with the ADC quickly with the levers to the left and when I adjusted it the image got worse BUT I had a diagonal fitted which would have caused this to happen.

 

Edited June 30, 2020 by StargazingAde
updated information

[StargazingAde]

Just an update on my Omegon ADC. after doing the test it appeared to be a left hand ADC but as usual the weathers been doing it's best to ruin things but finally just a chance to try it out again on Jupiter with the CPC1100 and ASI290MC and even though I had to use nearly all it's corrective ability, I still managed to get the images attached - not the best by far but seeing the conditions were so bad, I am happy!.

Edited July 5, 2020 by StargazingAde