The Filter Wheel and the Focuser - they're important too! Starting astrophoto for lazy people Ep 9

[@arvind3888]

You have explained back focus so well man 👌

[@CuivTheLazyGeek]

Glad you think so!

[@MrGChuff]

Another useful vlog thanks, nailed vignetting 👌.

[@CuivTheLazyGeek]

Yeah, I got the pronunciation right! :D Thank you!

[@EastSideAussieQuest]

Thanks for the excellent video again, also thanks about avoiding DC Focus Motor. Will go with the ZWO EAF. Keep up the great videos. 🙂

[@Pescadoraficionado]

Thank you Cuiv! I Will Look your video about autofocuse. I have a EAF too with 200 steps of backlash and I have never get the V or U form on SGP so i can not be lazy. I will try on nina. Clear skys from México!

[@CuivTheLazyGeek]

I really hope you can get it figured out! Good luck and clear skies!

[@stormingbarney4498]

Thank you for these video episodes- really enjoying them and finding useful. Just bought the EAF and find it is about mm off when returning back to 0 position, but will now try the backlash setting as I’ve eliminated any slip in the focuser tube.

[@CuivTheLazyGeek]

My pleasure, and I'm glad these are useful! Backlash should indeed be the last thing to deal with, and the easiest - if you're using NINA, I strongly suggest using the Overshoot backlash compensation method.

[@AnakChan]

How much is refocussing a necessity for scopes of slower focal ratios of F4.9 to F10 when changing filters? I thought if all the filters were the same brand & thickness, I wouldn't need to refocus when flipping filters. Also good point on belt driven autofocusers. I didn't consider slippage. I have the K-Astec NanoFocus for my FSQ-85ED but have not checked if there's any slippage. I've not used too much PC driven software (i.e. N.I.N.A or SGP), but w.r.t. your comment on belt driven autofocus introducing vibration messing up autoguiding, wouldn't the autoguiding be suspended during the focusing routine in the schedule? Or would stars still be autoguiding during the focusing routine? What would that mean for OAGs since it's a part of the optical focusing train?

[@CuivTheLazyGeek]

Still very necessary in my experience - my EdgeHD @ F7 was very sensitive to focus shift throughout the night. Unfortunately, filters may not have the exact same thickness, or I would assume even the same overall refractive index, affecting focus. Plus optical systems with lenses (including focal reducers) may not focus R and B at exactly the same spot, even if aberration is well controlled and the filters are strictly identical besides the color. Focus is visibly affected by changes of fractions of a millimeter! In NINA, you can indeed suspend autoguiding during autofocusing for OAGs, and for belt focusers (for those, you can in addition have a settle time). If you use a separate guide scope, it makes sense to keep guiding, especially if doing long (10s+) AF exposures with narrowband filters for example.

[@elapid13]

Thanks Cuiv, just bought my first EAF and find your videos most useful :)

[@CuivTheLazyGeek]

Excellent to hear! Autofocus can really change your life -I hope you'll get it set up and working without too many issues!

[@salomon1639]

Thanks for the great video. I had a zwo eaf with backlash of 800 I know that sounds crazy. I removed it and noted an oil leak around the shaft. I sent it back to highpoint scientific and they sent me a new one. Not sure if it was defective. While I w as waiting for the eaf I bought a new Pegasus cube 2 and initially backlash was 65 but now at 250. I made sure all the screws are tight and focuser well aligned with focuser shaft of telescope (esprit 100). Any suggestions as to why backlash is increasing? Thanks for any input.

[@CuivTheLazyGeek]

800 backlash?!? Now that's a lot indeed. Good that the shop sent you a new one, that is simply not acceptable. Any increasing backlash suggests that gear meshing is slowly getting sloppier and sloppier, so maybe some gear supports in the gearbox are not properly secured? I have never seen that, but in theory possible indeed...

[@CitizenSniiiips]

Ah you sure you're not overloading the payload capacity of the focuser? Does your drawtube move smoothly? Instead of backlash what you could be seeing here is the focus motor slipping because even 250 is a LOT. I've not heard of the focus cubes having issues with backlash at all, not like the EAF

[@BrokenPik]

i own 2 Pegasus focusers and both run 200 steps backlash "IN" with steps of 125 my curves are perfect ( SGP. NINA) HFR 2.25 nightly on my VRC6 @ 834mm F5.5 so its not uncommon ....

[@EastSideAussieQuest]

When installing the EAF do i have to make sure the scope is in focus or will the EAF figure it out. ? Will be using the EAF with ASi Plus. & asi 224mm mc camera

[@fernandoapausa4931]

Nice video again Cuiv, thanks. I just bought my first electronic focuser. I went for the Celestron motor focuser for my Celestron SCT 9.25. I did not see too many options for Smith-Cassegrain tubes and decided to stay with the same manufacturer, as it should guarantee at least the compatibility, even if I had not found too many reviews on it.. do you have any good or bad reference of it?

[@CuivTheLazyGeek]

My pleasure Fernando! I've heard good and bad things about that focuser, but the overall feedback seems to be that it is serviceable, which I think is good. You should check out James Lamb's channel, he has the same focuser, and a Celestron SCT, and is obsessed with autofocus! So it should be a great source of information for you. Good luck & clear skies!

[@BrokenPik]

After all that work and now you need new Flats ,, ergggg LOL

[@CuivTheLazyGeek]

Yep!!! Painfully aware of that - you can almost see me in the video reach that decision point: oh well, I'll sacrifice myself for the sake of better explanation!

[@BrokenPik]

@@CuivTheLazyGeek well done ...