A zwo adc landed today i downloaded the manual but your video is far easier to understand thanks for taking the time to explain it in an easy way for everyone to understand.

I liked that yellow part you put in focuser knob...😅 congrats for the video!

Excellent demo, many thanks!

Never heard of this ADC so very interresting! Thanks!

Brilliant video, thanks. Especially the position of the levers and the resulting image side by side.

Excellent, lucid explanation, thank you.

I love this channel, what makes it even better is your crystal clear narration, just awesome. Thank you.

@JenhamsAstro

4 жыл бұрын

Steve W Thanks!

@stevew585

4 жыл бұрын

@@JenhamsAstro My pleasure, after all, your the Guy that actually got me into this wonderful Hobby.

A Very simple but effective device. Thanks for the info.

Really informative video, thanks! ZWO should pay you handsomely for that work!!

Greeeat video, very helpful, thanks! Just a note: I have just discovered that it's possible to lock the position of the levels (to avoid eg. moving them by inadvertence) - just turn the levers like a screw, and they lock! Nice feature from ZWO :-) Clear sky!

@JenhamsAstro

3 жыл бұрын

Wow, I just tried it! Excellent tip, thanks!

@nervenerd

2 жыл бұрын

same with the plastic datum screw - when loosened this allows the ring that also carries the bubble-level to be rotated with respect to the body of the ADC, which can be securely clamped to the telescope etc. However, it should of course be tightened once correct leveling has been achieved. If you are tracking Venus one would have to frequently loosen, level and re-tighten the ring. See my recent extended comment.

Great tutorial! Very clear presentation! Thanks.

This is the best explanation I've seen so far on the ADC. Thank you!

@JenhamsAstro

Жыл бұрын

Glad it was helpful. Clear skies.

That's a neat tool, did not know about it before. Great video 👌

Good video and you explains it in a easy way. Thumbs up!

Very well done demonstration.

Great Tutorial, thank you for sharing.

Great video and showcase of the changes with the ADC! Firecapture has a great ADC turner option in case you are unaware (you line up the circles until on top of each other)

@JenhamsAstro

3 жыл бұрын

Thanks for the tip! Clear skies.

Well done for 1st attempt!

Thanks for the exellent toutorial, i'll finally be able to use the ADC with confidence.

@JenhamsAstro

4 жыл бұрын

Glad it was helpful. Clear skies (with comets)!

Thanks for such a clear review. I was actually using it wrong at first. Actually I came back to your video a second time.to check if I had lost a screw. There are three threaded holes at 120 degrees apart, but one does not contain a screw. Had a feeling it was fine.. but nice to be able to double check cheers.

Thank you for this clear explanation of the ZWO ADC! I also have one and I'm waiting for a chance to use it. Just have to wait for a cloudless sky:-).

@JenhamsAstro

4 жыл бұрын

You are welcome! I too have seen a lot of clouds recently!

Thanks very much for this great video!!

Nice Demo On The Tool. Will have To Look for One Of These 👍🏻🔭😃

Great video, many thank's.

Surprisingly effective.

Excellent video. Seems to provide a decent return on the investment.

Nice Tutorial Thanks.

Excellent Demonstration 8:57 - Good work Jenham!

@JenhamsAstro

4 жыл бұрын

Thanks Ray. The purchase of astro kit heralded the usual period of bad weather with many dusks coinciding with cloud obscuring the lower 20 degrees of my western sky. Finally a clear evening allowed the test. Clear skies, Graham.

Thank you 🔭

Excellent

Excellent thank you

thanks a lot for this video!!!!

thanks a lot for this video

That’s an interesting device. With the little I know about optics, it’s hard to imagine how it works!

@JenhamsAstro

4 жыл бұрын

It does have a slightly mysterious quality! I found a ray diagram online somewhere which went some way to explaining it; certainly a clever idea by its inventor. Clear skies!

@0LoneTech

4 жыл бұрын

I reckon the prisms each cause linear CA; in the neutral lever position the prisms are in opposite directions so their effects cancel out. As you turn them, they begin to agree on the direction and cause a variable degree of dispersion.

Great video Sir. Can this be useful with my Mak 90 with ASI 120mcs camera , uv/ir cut filter and with a 2 x Barlow?

Hi Luke, great video mate! I am about to purchase an ADC to use only for visual with my 9.25" SCT. Do you still recommend it for visual? I know large aperture scope can be prone to more CA as you magnify on bright objects so I am hoping this can improve my visual work and make the image cleaner. Cheers

Thank you this is good. How is firecapture do you know when you have enough correction.

@JenhamsAstro

3 жыл бұрын

Thanks. The red and blue circles merge with the white when the amount of correction is right. I still make the first adjustment of the levers whilst looking at the image of the planet, then go back and forth to the ADC tool.

@Pipe-organ-recordings

3 жыл бұрын

Jenham's Astro Thank you

Nice video. Have you figured out the point of enabling one to rotate the bubble level ring to any position? I thought the idea was to use the level to establish a unique "null position" of the prisms from which they can be rotated. But if you are free to rotate the bubble level to any position that seems to defeat this idea... Am I missing some important point?

Excellent video. Really clear explanation of a piece of kit that has an aura of mysticism about it. My questions are, does the amount of offset on the levers correspond to the relative altitude of the planet above the horizon ?? So would you need to keep re-adjusting for Mars for example as the night progresses and the planet rises. With that in mind, did you think it was easy to establish the optimum position by visual or live viewing on the screen ?? ie. not having to do some on the hoof processing to get the stacked result. Many thanks in advance.

@JenhamsAstro

3 жыл бұрын

Thanks Sean. To my simple mind yes, the lever separation should be reduced as the planet rises, upto a point at maybe 45 degrees, when the dispersion is minimal to my eye. I use liveview on my laptop, and can see the effect fairly easily, especially for brighter planets. Generally it negates any need for RGB align during stacking, or at least reduces this stage to a tweak. I'm using a colour camera BTW. There is a feature in FireCapture as an alternative, but so far I haven't used it. I have read a very useful article on skyinspector - worth a look. skyinspector.co.uk/atm-dispersion-corrector-adc/ Clear skies. Graham

Brilliant video! Thanks. You definitely should be getting a cut from ZWO!

@JenhamsAstro

2 жыл бұрын

I wish!

Thanks Graham. I have just ordered one of these in anticipation of upcoming oppositions of Jup, Sat and Mars. One quick query. You mention you can attach the unit to the telescope via a T thread. I always prefer threaded connections so that is good to know. Only issue is, how do you adjust the unit to keep it level with the horizon if it is threaded on? Great video BTW!!!

@JenhamsAstro

4 жыл бұрын

Thanks Malcolm. I've just taken off the 1.25" adapter to reveal the T-thread, and had a try. I think if it is threaded onto your drawtube then you have to either be able to rotate the whole focuser and relock it when the target is in view (I can do this on my GT81), or if the visual back adapter can be rotated and locked then that would work too (e.g. as on a Skymax 127). Otherwise I don't see a way, as the spirit level is fixed to the same part of the ADC which has the T-thread. I'm sure Baader have a clever adapter to allow it though, if you can find it!

We should all chip in to get Jenham a Skymax 180 to do Testing on planets with the other smaller ones

@davestory6123

4 жыл бұрын

Land of Celts He’s got plenty of scopes but feel free to crowd fund me a 180 mak 😉😊

@Eire32

4 жыл бұрын

davestory I would if everyone gave 10 Euro 💶 have you not got a telescope 🔭

Great video! This prism couple will be very useful for Venus and probably Mercury and for others when they are in sky between Virgo to Aquarius and are closer to horizon. Well made. Would you mind if I ask how you put the little images together? By the way it seemed to me at the 1.5 bold line mark the image was sharper, although it was slightly orange at the lower limb of Venus; maybe due to air becoming more stable at that few moments.

@JenhamsAstro

4 жыл бұрын

Thanks. The small video frames were made by processing the original .avi video using the "PIPP" software, to centralize the planet and reduce the frame size. Then the still images were made by aligning and stacking the best 100 frames of this video file using the Registax freeware.

@TheAstronomer

4 жыл бұрын

@@JenhamsAstro Thank you so much for your kind reply. I see you are selling your original Celestron Maksutov 90.

@JenhamsAstro

4 жыл бұрын

Hertfordshire Allotment Life Yes, it is gathering dust and I am now trying to sell Astro kit before buying something new!

How to use this device with 2 inch diagonal? can it be put in diagonal vertically and then fitted with ocular for visual observation?

Sorry the following is long-winded but things area bit more subtle than the video shows (though it's basically correct). OK, after examining the physical ADC, the video and the comments a bit further, I realize that the white plastic "datum screw" is mounted on an independent ring, and that if the screw is loosened, this ring can be rotated. The datum screw is fixed at 90 degrees to the bubble, so the bubble can (at least to some degree) be leveled to horizontal while the unit is firmly attached to the telescope. I believe that the zero separation initial position of the 2 levers should be set to the datum screw (and therefore exactly parallel to the horizon),as Graham says. The key point is that this zero-separation starting point for both the 2 levers must be horizontal. I suspect that in the zero-separation position neither of the prisms is deflecting the light. Possibly the prisms differ slightly in their spectral transmission properties, with one letting through relatively blue light and the other relatively red light. So the different atmospheric refraction for red and blue light can be corrected by a second adjustable refraction by the ADC. Thus in effect without the ADC in place one is looking at near-superimposed red and blue versions of Venus which are slightly displaced with respect to each other (accounting for the artifactual or false colors seen since Venus is always close to the horizon). The ADC allows these 2 images to be correctly superimposed so the artifactual color disappears, though the required amount of correction has to be empirically determined, though it does depend on the altitude of the object. Presumably this blue-red false displacement is in the vertical direction (perhaps because it's ultimately due to the slight difference in the thickness of the atmosphere corresponding to the top and bottom edges of Venus). If this is correct it throws light (so to speak) on the issue of the fact that, at least in my instance of the Zwo ADC when set to the datum screw both levers can be moved in both directions albeit much more in one direction than the other. It could well be that the datum screw ring should be initially set to a starting position such that when the 2 levers coincide they are equally far from the short end of their travel range. (This may well be the factory-set position - I did not take a photo of the unit straight out of the box, but I think it was at least approximately true.). Then the ADC should be attached when the telescope is roughly pointing at the expected altitude of Venus (i.e. slightly upward from the horizon). This would mean that once pointing at Venus one can rotate the datum ring so as to accurately level the bubble, which, if the levers both initially coincide with the datum screw, would set the 2 prisms to the zero diffraction position. Assuming that the prisms always have to be rotated in exactly opposite directions to achieve correction, this would ensure the maximum amount of correction (e.g.with Venus very near the horizon) could be achieved. This would account for the fact that in the video (at 3:03) when Graham holds the ADC horizontal with the 2 screws that operate the retaining brass circle pointing down, the bubble is roughly horizontal and the datum screw is parallel to the horizon. Presumably this was shot straight out of the box, with the factory setting. I think understanding how the device operates is useful for its correctuse (which, by the way, I've not yet achieved).

An excellent review of the ADC, and waiting on a clear night to put my newly acquired unit to the test. I do have a question though. I understand the need to have the ADC set parallel to the horizon to make the adjustments to the prisms in order to remove the colour, but I am assuming that as the scope track over several hours the ADC body will need to be constantly adjusted to maintain the prism orientation. IF this is the case, the camera FOV will rotate with the re-orientation of the ADC. Is this the case? The orientation of the planet in the image will need to be de-rotated or have the camera body rotated the opposite amount each time to keep the image consistent. Is this the way it works or am I missing something? Again, I have yet to have a trail at the scope. Thanks, Brian

@JenhamsAstro

3 жыл бұрын

Thanks Brian. That's a good question! In theory I suppose yes, but in practice the duration of the video capture for a planetary image is so short (a small number of minutes at most) that it isn't necessary to adjust the bubble during a given exposure, only in between if you are imaging over a significant time vs the angular movement of the original "horizontal" setting. I could be wrong, but to my mind the video & stack method is not sensitive to the issue compared to long exposure DSO imaging. Does that make sense? Graham

Very useful indeed. It leads me to consider whether I would ever buy a Baader filter for 'fringe killing' on my 120mm achromat Star Travel. I can only assume that, if it can rid the atmospheric fringing, it can also eradicate the chromatic aberration in an achromat (to at least the same extent as one of these filters). What do you think? Have you checked that out?

@JenhamsAstro

Жыл бұрын

Unfortunately an ADC won’t correct for CA in a fast scope. An ADC only corrects for colour displacement in one plane. There isn’t a simple fix to the CA at f/5. I’d tolerate it and put the money towards an ED/apochromat rather than buy a fringe filter. Enjoy the 120 as a lightweight simple scope which isn’t perfect. Just my 2p.

how do you calculate the back-focus to camera ? some adapters are needed?

Hi, really good video, simple, pragmatic. Thanks. Why are you using a Barlow 2x with a Mak 127? Does it really worth, or, are you already over the sampling of your camera ?

@JenhamsAstro

Жыл бұрын

Hi, it's to get the focal ratio into the desired range, so that the image scale matches the camera pixel size. In good seeing the ratio is OK with a little over sampling.

Great video! Quick question. I have Mak127 and 2.5x powermate. I have attached the ADC to the telescope and inserted powermate in to it. What do you think about the order when installing ADC and barlow/powermate?

@JenhamsAstro

4 жыл бұрын

Hi David, I think the choice of the best ordering of components in the image train is not that clear cut, but two key aspects are to ensure that resulting f/ratio works with your camera, and to ensure you retain the ability of reach colour correction before the levers reach full separation. Your setup of scope-adc-barlow-camera will probably be better than having scope-barlow-adc-camera because you will get a lower overall focal ratio that way. With my 2x barlow it works OK as scope-barlow-adc-camera, but for your 2.5x i think you've got it right. Whilst disappearing down the internet rabbit hole to research your question i came across some interesting ADC analyses on the "SkyInspector" website. Worth a look. I hope this helps a little. Graham

Can it be helpful with a 90Mak?

Very useful video! Have u tried to thread the adc to the televue 2x barlow instead of directly to the telescope. I would like to shorten my imaging train but not sure if with this barlow that is possible i mean to thread it into the adc. Thanks!

@JenhamsAstro

3 жыл бұрын

Thanks. Not sure how I'd thread my barlow onto the ADC? Do you mean telescope + ADC + barlow + camera? I also read an interesting article here skyinspector.co.uk/atm-dispersion-corrector-adc/ Worth a look.

@UV-NIR-Thermal

3 жыл бұрын

@@JenhamsAstro Thanks for that link, thinking of getting one of these now

Thanks for this. I noticed you connect via the nosepieces. Does it affect the ADC performance at all if you remove either of these (e.g. on camera side) and screw the camera direct into the ADC. That will reduce my optical path length which is helpful for achieving focus.

@JenhamsAstro

Жыл бұрын

Hi Rob, I haven’t tried this but will try to in future. It might also help rigidity of the optical train.

@RobWalker_R023

Жыл бұрын

@@JenhamsAstro Thanks. I initially set mine up with no nosepiece, so was going to give it a try. But realised I'll be switching from OSC (ASI678MC) with normal uv/ir cut plus also some extra subs with an IR685 on the ASI220MM. So the easiest "swap" mid session is to just slide out the OSC from nosepiece and drop the mono in with filter already in place.

I think the 0.75 position suits it best.

Hello. You said that the ADC must always stay horizontal. If I want to use a diagonal mirror in visual, how do I connect the ADC? Do I have to connect the ADC directly to the telescope, then the diagonal mirror, and then the barlow + eyepiece?

@JenhamsAstro

Жыл бұрын

I haven't tried using my ADC for visual. From the forums I've seen photos of scopes with the scope then diagonal then ADC then eyepiece. In case you haven't seen it here is a useful page: skyinspector.co.uk/atm-dispersion-corrector-adc/

Is that a peanut butter jar lid on your focuser?. I’m trying to find a lid of the correct size myself lol.

@JenhamsAstro

2 жыл бұрын

Marmite!

Hello, may I ask if the ADC is only advised when objects are near the horizon or does it give always a bit improvement to the object we want to observe. Thank you

@aranbarrett9543

2 жыл бұрын

I was thinking of the same question to ask.

Since you can spin the horizontal bubble, why does it matter if that portion is actually level, confused on that part. Or should that bubble only be at a certain point on the adc and not moved

@JenhamsAstro

3 жыл бұрын

Hello, the dispersion is in a vertical plane so the correction via the ADC prisms must be applied "up/down" i.e. vs horizontal. Once set parallel with the horizon, the bubble doesn't spin as you rotate the levers and hence the prisms, but it is defining the datum axis for the prism rotation. I've found a good page here which explains it better than i can! Clear skies, Graham skyinspector.co.uk/atm-dispersion-corrector-adc/

Thank you. Very interesting! Can I use it with binoviewer?

@JenhamsAstro

4 жыл бұрын

Sergey Sergeev Hello Sergey, I haven’t tried it myself but I’ve seen on the Cloudy Nights forum that the ADC can work visually with a bino. The only issue is to ensure you can reach focus with your setup. Not a firsthand report I know but I hope it’s of some use. Graham

@Sergey_Sergeev

4 жыл бұрын

Jenham's Astro Thank you, Graham. Never got the answer so fast on KZread!

Hello The ADC can be used to removed the chroma aberration of the refractor ? Thanks

@JenhamsAstro

4 жыл бұрын

C Anti-cons Hi, I don’t profess to understand why, but the answer is no. An ADC can’t fix CA due to a scope’s optics.

@contribuable3963

4 жыл бұрын

@@JenhamsAstro thanks

@0LoneTech

4 жыл бұрын

@@JenhamsAstro That would be because the lens CA is radial in nature (center to edge of lens), while the ADC is linear (up-down). Or put another way, we're looking through the outside edge of a giant lens composed of the atmosphere facing our target, with the center being far below the horizon. If we were looking at zenith, we'd be near the center of that lens, but it's also far thinner that direction so may not produce significant CA.

How can I connect my ZWO ASI178MC with the ADC because the ADC is T2.

@JenhamsAstro

Жыл бұрын

The ADC accepts cameras with a 1.25” nosepiece. The 178 is normally supplied with one I think.

Good report! Should be possible to calibrate the device based on the degree elevation of the planet from the horizon since the dispersion changes with object elevation. I'd also like to point out that this device is CHEAP for what it does. The only alternative I've seen so far is a $4000-$5000 German device.

I've seen people using it to take photos of the moon. Do we really need it to take photograph the moon (especially when it's not near horizon) ?

@JenhamsAstro

3 жыл бұрын

I would say no, if the moon is high.

Hi, I just received my ADC, can you tell me where everything should be set (starting point) before anything is adjusted please? Including the ring with the bubble on it please. Thank you.

@JenhamsAstro

3 жыл бұрын

Andy Heath Hi I think my previous reply was lost... you need to have the bubble level horizontal at the top and then you would have the zero adjustment marker to the right and the two levers next to it together and horizontal, and then you separate the two levers up and down around that datum position

@JenhamsAstro

3 жыл бұрын

You need to adjust the level to be horizontal once you are pointing at the target.

@mrtelecaster009

3 жыл бұрын

@@JenhamsAstro Thank you, so just to be cleat, bubble at the top and the nylon bolt at 3 o'clock with the two levers at the same point. I the seperate the two lovers in opposite directions at equal amounts using the white markers? I think that was right?

@JenhamsAstro

3 жыл бұрын

Andy Heath Yes that’s right for my ZWO ADC. As such it’s called a right hand unit. Some other makes are left handed (levers @9) apparently.

@mrtelecaster009

3 жыл бұрын

@@JenhamsAstro Thank you, this is defo a right hand unit, thank you for your help with this

So is this only useful when the planets are low in the horizon ? What would be a threshold, 20° ? I remember imaging Mars in 2020, probably around 30-40° and I was still seeing some shifting between RGB so it seems it could be useful pretty much all the time ?

@JenhamsAstro

10 ай бұрын

Hello, I think it can be useful beyond 20 degrees. I find it’s a matter of trial and error to get the best result rather than using the ADC only below a certain altitude.

@astrodysseus

9 ай бұрын

@@JenhamsAstroI am a little concerned on the usability of ADC; Seeing is generally the limiting factor for planetary imaging.. and if seeing is poor, I am quite unsure I will be able to see any indication on the live preview of a RGB shifting.. Btw, how did you activate the RGB shift on the left side panel of firecapture, to the right of the RGB histogram ? I don't remember that option

@JenhamsAstro

9 ай бұрын

@@astrodysseus It can't correct for bad seeing but, only for dispersion at low altitudes. There is a good page on it here: skyinspector.co.uk/atm-dispersion-corrector-adc/ Sorry I don't see the FC control you are refering to.

@astrodysseus

9 ай бұрын

@@JenhamsAstroI wasn't expecting a miracle for bad seeing - even though that would be fantastic - but indeed i was wondering if an ADC is really useful if your planet is above let's say 35°. I am not entirely sure it is. When it's low in the horizon, it seems we probably need to recalibrate the dispersion every 5-15mn ?

@JenhamsAstro

9 ай бұрын

@@astrodysseus Certainly more useful when lower down. You do need to play around with the levers to remove the fringing - some trial and error there which FC helps with. And you need to keep the prism axis parallel to the horizon as the altitude changes. So your initial setting does need to be tweaked. I do this every few minutes if I’m taking a series of captures. I’m no expert, but it seems to work better than an RGB align in post processing.

Why does it have to be horizontal? And how can it be if Venus is above the horizon?

@JenhamsAstro

2 жыл бұрын

The dispersion the ADC is trying to correct is in a plane such that the prisms need to be aligned with the horizon. You would centre Venus, rotate the ADC in the focuser so that the bubble level shows the prism axis is horizontal (parallel with the horizon), and then rotate the levers.

@nervenerd

2 жыл бұрын

@@JenhamsAstro - thanks for the clarification, which I sort of figured out when I tried it (and read more of the comments). However, it's still not clear to me how to do the necessary leveling: it seems one has to rotate the entire ADC unit relative to the telescope tube, but how is that possible unless the ADC is not securely fixed to the visual back? If I am to rotate the ADC the attachment to the visual back has to be loose - which means that when the telescope is inclined (as it has to be since Venus is above the horizon) everything - the ADC, eyepiece, camera etc, can simply crash to the floor as the ADC slides out of the visual back under gravity's pull. Also, the 2 levers can each be moved in 2 directions relative to the (now horizontal) datum plastic screw. In one direction there is plenty of movement, in the other only a restricted movement. Which direction does one move the levers? The fact that one can move the levers in the restricted direction (somewhat) suggests that there are conditions where such a correction would be necessary. Or does "no correction" apply when the levers are rotated fully in the limited direction? - and when the levers are aligned with the "datum screw" there is already some degree of correction applied? In practice, last night, the best "correction" seemed to be when the levers were both at the datum position and not separated at all! However since Venus is always moving and therefore one has to constantly re-level the bubble, it's difficult to be sure about this.

My ADC didn't come with a Spirit level

If the device comes with no documentation, is this tribal knowledge you gained from a salesman? How on earth are people supposed to figure all this out without at least some description of how to use the device?