Choosing a filter-wheel - manual or auto?

[old_eyes]

So I have my new mono Atik 314L+ to use with my Equinox ED80, and now it is time for filters and a wheel.

Fillters is easy as I like the look of the Baader CCD 1.25" LRGB and 7nm Ha. But what wheel?

I don't have an much in the way of automation yet, just autoguiding with PhD Guiding. So the rig will not be working unattended for long periods of time. The nice Atik EFW2 that matches the camera is near on £300 more than the manual Tru-Tech Supaslim, and I can buy some of the other things on my wish list with that!

But, if I am constantly screwing up which filter I am using, an automatic filter wheel might be money well spent.

If anyone is using the Tru-tech manual wheel; does it have a good indexing system so that you know which filter is in place and that it is correctly positioned?

Any other thoughts on filter wheels gratefully received. I know it is an important part of the imaging train, but I don't want to spend a fortune now if I don't have to. I can always upgrade later.

Thanks

old_eyes

[steppenwolf]

I have to say that although manual filter wheels are the best value for money, they are nowhere near as convenient to use as an auto-wheel but more importantly than that, by their very nature, manual wheels have a protruding edge for your thumb to nudge the wheel round with and this can be source of light and dust ingress, both of which are highly undesirable. (That's got to be my longest sentence yet!)

Something to bear in mind though is that even though you may have bought 'parfocal' filters, in reality this isn't always the case in real life so it is wise to re-focus between filter changes. This doesn't mean that you can't still take advantage of the automated filter changes though and you could go to the next step and have automated focus control too.

[blackparticle]

I managed to pick up the manual version of the 1.25" Atik filter wheel for £80 brand new. As a budget option they are very well built and the filters can be accessed through the holes for easy cleaning.

I've not used it for imaging yet beyond testing it out but I imagine a small, black piece of cloth can be draped over it to help prevent any unwanted light entering.

The wheel itself is numbered so you do get a visual indicator of what filter has been selected.

[old_eyes]

I have to say that although manual filter wheels are the best value for money, they are nowhere near as convenient to use as an auto-wheel but more importantly than that, by their very nature, manual wheels have a protruding edge for your thumb to nudge the wheel round with and this can be source of light and dust ingress, both of which are highly undesirable. (That's got to be my longest sentence yet!)

Something to bear in mind though is that even though you may have bought 'parfocal' filters, in reality this isn't always the case in real life so it is wise to re-focus between filter changes. This doesn't mean that you can't still take advantage of the automated filter changes though and you could go to the next step and have automated focus control too.

Yes I guess light ingress is another problem. I remember Olly at Les Grange swearing mightily when troubled with light leakage from somewhere on his manual wheel. But £300 is £300 I could use elsewhere. I could buy a big piece of really black cloth for that!

Maybe I should look at the Starlight Express wheel - it nicely splits the difference between the Tru-tech Manual and the Atik EFW2 on the FLO site.

What do you use Steve?

old_eyes

[Komet]

Maybe I should look at the Starlight Express wheel -

Very nice piece of kit. I use a 7 slot 1.25" version. Having used manual wheels in the past I could not go back.

Also expandable over time with the SX OAG also (nice!)

[pete_l]

But £300 is £300 I could use elsewhere. I could buy a big piece of really black cloth for that!

The thing is, in a year or two the £300 you spent on an automated wheel will have been forgotten. However, if you go with the manual wheel, every time you use it for years to come, you'll think: "I could have had a motorised one"

[martin_h]

I use the Tru-tech manual wheel and find it very good indeed, there is an index mark on the knob, I use sticky lables attached to the body for filter position. The indexing is very accurate - so much so that I have another filter holder and when I change over everything is parfocal...within the tolerence of the filters.

[Earl]

One thing to consider, a motorised one is another thing to go wrong.

Saying that when everything works smooth its great!

[old_eyes]

I use the Tru-tech manual wheel and find it very good indeed, there is an index mark on the knob, I use sticky lables attached to the body for filter position. The indexing is very accurate - so much so that I have another filter holder and when I change over everything is parfocal...within the tolerence of the filters.

Martin, do you ever suffer from light leakage on the filter wheel?

old_eyes

[old_eyes]

One thing to consider, a motorised one is another thing to go wrong.

Saying that when everything works smooth its great!

Hey - when you already have a rats' nest of wires all over the place, ready to trip you in the dark, what's a couple more?

[shaunster]

You know there is a really simple way to stop light leakage that I use, its called a black sock... Saved me £300

Not once have I thought... 'I Could have had a motorised one'....

[old_eyes]

You know there is a really simple way to stop light leakage that I use, its called a black sock... Saved me £300

Not once have I thought... 'I Could have had a motorised one'....

Hi Shaunster - a bit my feeling. At the moment I plan to be 'in attendance' throughout imaging runs, therefore what is the problem with manually shifting filters. As I said, I can always upgrade if I ever go fully auto. My main concern was always, can I see what filter I am using and be sure I have it properly centred. Everyone's view seems to be yes. If true, then it meets my needs, with the addition of a black sock.

old_eyes

[steppenwolf]

You know there is a really simple way to stop light leakage that I use, its called a black sock... Saved me £300

Not once have I thought... 'I Could have had a motorised one'....

I like your style! But what about the dreaded 'sock fluff'?

[Earl]

Hey - when you already have a rats' nest of wires all over the place, ready to trip you in the dark, what's a couple more?

Very true, that was sorted this weekend.

Well when I say sorted I actually mean, its better than it was but still needs work..... LOL

[ollypenrice]

Yes I guess light ingress is another problem. I remember Olly at Les Grange swearing mightily when troubled with light leakage from somewhere on his manual wheel. But £300 is £300 I could use elsewhere. I could buy a big piece of really black cloth for that!

Maybe I should look at the Starlight Express wheel - it nicely splits the difference between the Tru-tech Manual and the Atik EFW2 on the FLO site.

What do you use Steve?

old_eyes

Hee, well I don't remember that but, I tell you, I have sworn more mightily than that when my daft electric wheel comes up with 'Device not recognized' (which means warm up the imaging camera, lose the mount alignment, lose the guide star, reboot the computer, re-cool the camera, re-frame the target and re-find a guide star. Oh look, the morn in russet mantle clad walks oe'r the dew of yon high eastward hill! Sausage egg and bacon, anyone?) So there are fors and againsts. I have an electric sitting here and I don't use it because I know that, like all the other USB controlled junk in the observatory, its primary role in life is to wreck a pleasant evening's imaging. Oh how I rue the day I bought a computer controlled mount! Give me a handset every time. If you can lose a USB device, do so. This is my credo! 95% of all equiopment hassles come from PC control of equipment and, because I'm doing this all the time and want people to go home with results, I give Bill Gates as few opportunities as possible to pull the plug on us...

Olly

PS, Hope my swearing wasn't too Gothic!

[AndyUK]

I have a manual Atik filter wheel (primarily bought through budget necessity) and so far it works fine. The only two criticisms I might have about it (other than possible light/dust ingress) are:

1. Being only 5 slot it doesn't "store" all 7 filters. Not that you would ever use all 7 in one night of course(!) - I tend to keep LRGB and Ha in it, but when you then want to take OIII or SII, you oviously have to take the wheel apart. (No big deal....)

2. Apparently there is NO Off Axis Guider on the market that can be used with the Atik MFW owing to the threadsize used (or so I've been advised )

If the latter is an issue then, then an SX EFW is probably the cheapest route, but if it's not, then like the sock solution, you might question splashing out the extra cash for a storage case and not having to replace filters every so often (which might take 10 mins each time).

(As I also resent Bill Gates screwing up my imaging sessions, I can't see myself wanting to "go electric" for some while...)

[old_eyes]

PS, Hope my swearing wasn't too Gothic!

Not at all. Entirely justified under the circumstances. Coupled with the Takahashi mount troubles you were suffering at the time it gave a whole new meaning to 'the patience of Job'. As I recall, the problem was solved with an artfully draped and, you assured me, freshly laundered pair of shorts. I think I saw the teacher in you then - intelligent use of the materials available to hand!

Having had a few nights of head-scratching wondering why the guide graph is an attractive saw-tooth pattern, or the computer refuses to connect to the mount, I think I am on the K.I.S.S. wing. Since I am going to be near the rig anyway, it won't kill me to exercise my thumb to change filters.

Hope the wedding went off well.

old_eyes

[Deneb]

Hi

Currently im using a Atik EFW2 it's got 9x slots all my filters are slotted in LRGB & HaHbO3S2, im just too darn lazy to be bothered changing the configuration inside the filterwheel.

But any of you chaps know of a decent manual filterwheel for 1.25" filters let me know, need it to be of a decent build ?

Where an electronic filterwheel has it's advantages, it's one more thing to go wrong & another power source to consider for.

@Shuan - Whats the Black Sock Method ?

Nadeem.

[shaunster]

@Shuan - Whats the Black Sock Method ?

Black sock around the filter wheel to stop light getting into the gap which you use to turn the wheel itself. Very simple but effective. I was getting gradients over my O3 frames until I used the black sock!

I like your style! But what about the dreaded 'sock fluff'?

Only a problem if you use a sock that has been on a sweaty foot all day...

[old_eyes]

Very Useful things socks!

[martin_h]

Martin, do you ever suffer from light leakage on the filter wheel?

old_eyes

No light leak what so ever, due to the design...the change knob is in the center of the wheel and very well shielded - I use 2" filters and have L,R,G,B,Ha in one cradle and OIII, SII in another and I have no problem changing over during a run if needed.

[martin_h]

Just a few pics of it in situ...

Pic 1 ...in situ showing the technical position marking:D

pic 2...open.

pic 3 spare wheel and protective box.

I have it mounted "Upright" so that when at Meridian it doesnt crack into the mount:)

[old_eyes]

...in situ showing the technical position marking:D

Love the labels. My kind of technology - direct and to the point .

RIght. Thanks to everyone. That's me sorted for the moment. Manual it is.

old_eyes

[ollypenrice]

We need a new and bitterly wrangled thread on socks versus underpants!

Tonight, roll of drums, I really do think I have finally got that Tak mount happy in its skin, by the way. Famous last words, I know.

Olly

[old_eyes]

We need a new and bitterly wrangled thread on socks versus underpants!

Tonight, roll of drums, I really do think I have finally got that Tak mount happy in its skin, by the way. Famous last words, I know.

Olly

FIngers crossed and touching wood for the Tak. I hope it realises it owes you big time!