Filters and manual filter wheels/sliders - for visual observing

[Pixies]

Hi.

Anyone here use manual filter wheels or filter slides for changing between different filters or none, when doing visual observing?

I'm finding it a bit of a pain to start swapping filters in and out. Especially if it's cold. I've dropped one or two and luckily not damaged anything, but it's only a matter of time with my fat fingers. So I thought the above might be a good idea. 

Cheers.

[JSeaman]

I use a manual filter wheel currently, I am more into imaging but you still need to change it when observing. I was using an EFW2 which is great but I love the simplicity of a manual filter wheel. I wouldn't dream of trying to change filters in the dark/cold now, very much recommended

[niallk]

Hi,

I got this one for my 250px:

It was transformative!!

No more pain of taking out an EP to screw on a filter, and often losing sight of a target - especially high power on planetary nebs.

It became a joy to flick from no filter to O-III or UHC - really making it convenient to try different options.  The 1.25" holder is a little cruder than the stock focusser on the 250px, but the no fuss convenience and ease of swapping filters - and swapping EPs - far outweighs the slight tradeoff.  It also acts as convenient storage - no more fumbling with cases.

For relatively low cost, it greatly adds to the observing experience imho.

Edited May 2, 2021 by niallk

[Voyager 3]

Do you have any focus issues with this setup @niallk ? 

[Shimrod]

On 02/05/2021 at 11:29, niallk said:

Hi,

I got this one for my 250px:

 

It was transformative!!

No more pain of taking out an EP to screw on a filter, and often losing sight of a target - especially high power on planetary nebs.

It became a joy to flick from no filter to O-III or UHC - really making it convenient to try different options.  The 1.25" holder is a little cruder than the stock focusser on the 250px, but the no fuss convenience and ease of swapping filters - and swapping EPs - far outweighs the slight tradeoff.  It also acts as convenient storage - no more fumbling with cases.

For relatively low cost, it greatly adds to the observing experience imho.

It's worth noting you can buy exactly the same filter wheels with a different (or no brand) on ebay at half the cost. I bought one last year for £25, although like everything else they have gone up in price and are now £38 - although still a lot cheaper than own-brand equivalents in the astroshops.

[niallk]

14 hours ago, Voyager 3 said:

Do you have any focus issues with this setup @niallk ? 

Hi, not in my 250px.  The EPs I used were: Pan24, N13T6 and N7T6, and also a PM2.5X.

Unfortunately I do have focus issues with my 15" dob.  I hope to get an Astrocrumb filter slide at some point (I now have 2" filters for that scope to match newer EPs - and back to the annoying swapping lark!!)

Edited May 3, 2021 by niallk

[Jiggy 67]

On 02/05/2021 at 11:29, niallk said:

Hi,

I got this one for my 250px:

It was transformative!!

No more pain of taking out an EP to screw on a filter, and often losing sight of a target - especially high power on planetary nebs.

It became a joy to flick from no filter to O-III or UHC - really making it convenient to try different options.  The 1.25" holder is a little cruder than the stock focusser on the 250px, but the no fuss convenience and ease of swapping filters - and swapping EPs - far outweighs the slight tradeoff.  It also acts as convenient storage - no more fumbling with cases.

For relatively low cost, it greatly adds to the observing experience imho.

That’s really interesting, I find it such a pain, manually changing filters, to the point that I sometimes don’t bother using them when, perhaps I could get a better result if I did.

One question though. How do you know which filter is being used at a particular time in the dark? Is there a way of recording which filter is in each slot that you can read in the dark?.....I’m sure I’m gonna look stupid when an obvious answer is given 🤥

[AlexK]

I've been poking the idea of the filter slider 3DPrinted for my z12 Dob inner wall (~$500 on the market, 50 cent to print). But lately I stick to just the Astronomik UHC, so no biggie to screw it on and off as needed, instead of worrying about constantly exposing its coatings to the elements in the field, adding the weight and bulk to the fine tuned OTA balance, bending the light path past the focuser, vignetting the UWA EP FOV, or adding glare or uneven aperture spikes...

I'm observing with the dedicate fishing vest on top of my layers, it has 8 pockets which I'm using to rotate my eyepieces with the minimized exposure (all pockets have zippers, dust proof, and all catching a bit of heat escaping my body to reduce dew chances) and one of them is dedicated for filters in their factory shipping plastic clamshell padded boxes.

Also, to screw filters on and off I have a simple technique developed over 30 years ago to prevent threads stripping, touching any glass, and with a zero dropping potential (never happened to me even in -30C Siberia winters causing "wooden fingers"). I call it "inside-out method": Just half-close your palm (in the mitten or not) and secure the filter in its center by as much edge contact as you can (I get a 100% contact grip even on a 2" filter rim). Threads out. Then screw on the eyepiece over it ("inside-out" is a misleading term I guess, but that's the closest translation to English I think :)))) ) using the typical technique of starting in reverse until it clicks. Unscrewing is similar, just when putting it back into the box do the same "inside-out" trick: place the box over the filter still perfectly secured in the center of your palm, (screw it in if your case has a thread) flip over, close, put in the pocket. Sure thing, if the box is grippy enough you can put the filter on right from the box as well. But usually they are gripping by the filter thread in a typical case, so I could see some dedicated for this method field filter box 3D printed eventually, but after 30+ years of doing just that I don't see it urgent yet :)))) (in fact, bare hand approach adds the benefit of warming up the filter a bit from your skin, so it wouldn't catch any moisture from the air while exposed).

Edited May 4, 2021 by AlexK

[Kon]

I do a similar approach to @AlexK but instead of using my palm I hold the filter with three or four fingers around its edges and then screw the EP to it and the reverse for removing it. I like the palm idea for cold nights.

[niallk]

22 hours ago, Jiggy 67 said:

One question though. How do you know which filter is being used at a particular time in the dark? Is there a way of recording which filter is in each slot that you can read in the dark?.....I’m sure I’m gonna look stupid when an obvious answer is given 🤥

 

😂 no, not a silly question!!

So I think I had no filter in slot 1, slot 2 UHC, Slot 3 O-III (see what I did there... 😉).  I only used 2 filters on DSOs, so easy to remember.  I filled slot 4 with a neutral density for the moon, and slot 5 I stuck in a green filter which I never really used on planets, tbh.

There are also numbers on the wheel,  so if you use a red light you could read them off.  Tbh, you get to know each of them by the views pretty quickly, so never an issue