How to use the ZWO Atmospheric Dispersion Corrector (Enhance your Planetary Images!) 

Thanks for the suggestion Tim! I'll give this a try to see if it works for me.

That's the way you should use the bubble level. In the video you are adjusting the bubble level to the levers, it should be the other way around. The bubble level is your starting point, not the end adjustment.

CORRECT SIR.

Yeah, it can be frustrating with no instructions but sometimes putting stuff together can be self explanatory depending on the application.

I'm glad you found this helpful! Thank you for the kind words!

It definitely save me a lot of frustration, lol! Thanks again, and I hope all is well on your end in Cyprus!

So glad that Kwasi mentioned your web page. I visited it today, and you have a bundle of helpful hints for Planetary Astrophotography, and especially Lunar Landscape Photography.

Always happy to help! Thanks for watching!

Thanks a bunch Luke! I hope you found it useful!

@@AstroParkAstrophotography Certainly! If I end up having a go at planetary properly I'll be taking another look at these I think 👍👍 thanks again!

Yeah, you have to move the levers equidistant from each other, and the test horizon line should be moving downward for both levers. You can use the tick marks on the rotating ring to measure the distance.

You have to remember that the position of the telescope changes with respect to the horizon line as the telescope slews and tracks your subject across the sky. So the way that I was taught was to find the max dispersion correction adjustment first before locking it down with the bubble level. I suppose what you're proposing could work, so feel free to experiment and see what works best for you.

@@AstroParkAstrophotography how do you find the dispersion level if it's not level with the horizon? You just be sitting the dispersion cock I had never be able to get rid of it all? I guess I'm confused. If there's a better way I'd like to know it.

Thanks for watching, and I'm happy to help! When I use an UV/IR cut filter, I thread it onto the camera and it works just fine.

@@AstroParkAstrophotography thank you for confirming the filter screws onto the camera, it made sense, I was just checking I was correct. Thanks again 👍

Unfortunately, I don't have much experience working with a Newtonian reflector. So I don't know for sure exactly. I heard somewhere that the bubble level would have to be aligned on the left side and everything else that I explained in the tutorial would be the same. Once again, I'm not exactly sure so feel free to experiment in the meantime.

This would be a nightmare on an EQ mounted Newtonian. But it still can be done with a Newtonian if you are mounted on an alt-azimuth mount. You would have to find that particular telescopes horizon line equal by sighting with it at a day target, like a tree or pole for example or the actual horizon - (NEVER LOOK AT THE SUN), even if upside down find the horizon line for your telescope and align your ADC ring with that - now you will not be able to use the bubble level going forward - you won't need it anyway. Also, your ADC bubble level should be at the top as in the video and levers pointing right as telescopes present an upside down image actually - if you are using a star diagonal (as with a visual setup or non-Newtonian) make sure the Bubble level is down and all levers point left now... I mark the imaginary line on my focus drawtube and set my ADC horizon to that reference; then as long as you leave it in place - don't move the ADC orientation and use the levers as normal you are good. Just to note if you are using a refractor or catadioptric type telescope then the advise in the video is going to work just fine.

@@Astroturf100 Tx. Sounds irrelevant then with EQ mount... May be relevant for my Dobsonian, at least it is alt-az, even if/when it will be on an EQ platform, it would be nearly level most of the time).

​@@TalGivoly Yes will work for a Dob or alt-az tracking mount too. But the EQ platform performs just like the EQ mount might be better but still going to be hard to get right. The only way to do this is to set the telescope at a neutral position, like a starting point if you will where the actual horizon line is going left and right in your eyepiece view parallel to the ground like in the video. Mark off the horizon line for this position on the facing drawtube this is the horizon reference line. Now find out where the ADC will be when the bubble is vertical when telescope is leveled and tube is horizontal in line with horizon. This difference is your telescope offset amount. When using the telescope and centering and tracking your target match bubble level just as in the video but then back the ADC position back by the amount of offset for your telescope you calculated earlier. Set ADC there and keep changing/rotating it as the tracking goes; vertically with bubble level at first and then add or subtract your offset ADC rotation each time (every twenty or thirty minutes as the video mentions). Once you have the offset amount for that telescope it doesn't change, this can be done but you see the difficulty.

@@Astroturf100 Do you get Atmospheric Dispersion on a Newtonian? I never have.

It's not recommended to use a focal reducer when doing solar system astrophotography. The planets are rather small in a camera's field of view, so using a focal reducer will make them appear even smaller. If one were to use a focal reducer with an ADC, I personally don't know of any manufacturers that make reducers which fit the 1.25 inch barrel of the ADC.

Hi Miles, if you're still having difficulty, you can also use the "RGB Align" tool in Registax during your post processing. I've seen people call the tool a "poor man's ADC", but I use it occasionally to remove any residual color fringes that my ZWO ADC may have missed. You basically trace a rectangle around the planet, and then click the "Estimate" button. The color fringes should be significantly reduced. You may also experience some stacking artifacts when you click the "Do All" button to apply all the changes, but you should be able to crop those out. It's a tool that works well, but I personally try to maximize my data capture quality out in the field with the ADC so I don't have to do intensive editing in post processing.

Actually, the dispersion is influenced by the position of the planet in the sky. As I mentioned in my example with sun, the lower the planet is in the sky, the greater the dispersion and the higher the planet is, the lesser the dispersion. So far, I've photographed the planets with an 8 inch Meade LX200 ACF and the Celestron EdgeHD 9.25, and I saw roughly the same amount of dispersion even with the larger aperture of the C9.25. The atmospheric turbulence via the seeing conditions were definitely amplified with an increase in aperture, but I didn't notice it as much when it came to the atmospheric dispersion. The RGB Align works well in Registax, as I use it in my editing process. The ADC, in terms of stacking, should help with determining the frame count since the contrast and sharpness are enhanced. However, the quantity of frames chosen is ultimately determined by the seeing conditions at the time of the video capture.

Atmospheric dispersion is an aberration caused by the atmosphere where the air molecules disperse the light from the subject like a prism. A telescope can have pristine optics, but can still experience color fringing from the subject due to the atmospheric dispersion. There's nothing wrong with the telescope, but the position of the subject in the sky will determine how pronounced the dispersion is.

ED glass only corrects for chromatic aberration. Atmospheric dispersion is an aberration caused by the atmosphere as the name implies, and is the most pronounced when the objects you're observing or imaging are low in the sky or near the horizon. It can affect even a telescope with the most pristine optics.

Thanks for watching Phillip! I do use an UV/IR cut filter with my camera out in the field. In the imaging train setup demonstration however, I wanted to focus on how the ADC properly connects with the camera and a barlow lens if you're using one.

The bubble level is used to track the maximum dispersion correction in relation to the horizon line. When the telescope tracks the planet in the sky, the bubble level will shift and re-introduce the atmospheric dispersion. Since the max dispersion correction was already set at the initial correction, you can move the levers up a notch at equal distances until the max correction has been reached again. Then you can re-align the bubble level and it will line up with the new horizon and max correction settings.

I actually used the ADC with my Schmidt-Cassegrain telescope, which has the focuser assembly in the back. So this tutorial will also work with a refractor since the focuser is in the back as well. Unfortunately, I don't have much experience with a reflector, but since the focuser is on the side, the setup will be a bit different.

@@AstroParkAstrophotography well done keep them coming!

I could be wrong, but from what I've heard, atmospheric dispersion shouldn't have much of an affect on mono cameras as opposed to OSC cameras. But you can use a OSC camera to get the ADC levels set up initially, then swap it out for your mono camera to do your separate RGB imaging.

It's one of those rare instances where the whole movie is quotable, lol!

What type of telescope?

@@nethertamer9943 C8

If you're still having difficulty, you can also use the "RGB Align" tool in Registax during your post processing. I've seen people call the tool a "poor man's ADC", but I use it occasionally to remove any residual color fringes that my ZWO ADC may have missed. You basically trace a rectangle around the planet, and then click the "Estimate" button. The color fringes should be significantly reduced. You may also experience some stacking artifacts when you click the "Do All" button to apply all the changes, but you should be able to crop those out.

I know, right?! The reviews that I read before buying this talked about the ADC having a good build, which I agree with. I didn't find out about the missing instructions until I opened the box, and I discovered later that others were encountering the same thing. Pretty poor business practices if you ask me.

Well I guess something good came out of it in the end, lol!

Hi Claude, I'm not familiar with the Sol'ex project. I did recently get a solar telescope in the form of the Lunt LS80MT. I did a visual observation so far and the view is fantastic! I'm looking forward to imaging with it soon, and I'll probably do another "My Telescope Family" video for it once I've used it for a while.