Filters for Binoculars

[Stormbringer]

Hi all

I have just bought myself a pair of Helios Apollo 22x85 bins  (hefty beasts)

They have threaded eyepieces for 1.25" filters and i was wondering what filters would be usefull to have and what the filters do

Cheers in advance

Alan

[Stu]

Hi Alan,

Nice binos, I had a pair myself. The kinds of filter which work best are UHC and OIII. These will enhance emission nebulae, particularly good under a dark sky for objects from M42 through to the Veil and North America Nebula. When I had mine I used one of each type because that’s what I had and they worked very well.

[LukeSkywatcher]

Would you use a filter on each eyepiece, so say UHC on both sides or just on one side and close the other eye? Kind of defeats the purpose of bins. Probably best to get 2 of each filters. 

[Stormbringer]

Ahh so you used the UHC in one eyepiece and the OIII in other 

thx for that Stu

[LukeSkywatcher]

1 minute ago, Stormbringer said:

Ahh so you used the UHC in one eyepiece and the OIII in other 

thx for that Stu

That's a possibility, but as I said you'd only see the effect with one eye, unless the brain takes control and shows effect in both eyes. 

[alanjgreen]

I use a uhc in one side and leave the other filterless.

If you blink you can compare the difference.

Your brain will merge the image.

Have not tried an O3 yet, but that will work too. 

More filters equals darker image. Try one and see how you get on...

Alan

[Stu]

5 minutes ago, Stormbringer said:

Ahh so you used the UHC in one eyepiece and the OIII in other 

thx for that Stu

Sorry if unclear. I already had one UHC and one OIII filter and did not want to buy a duplicate. I found that one of each type worked very well, and if anything it gives you the combined benefits of both types of filters in one view. A UHC tends to show the greater extent of nebulae whilst an OIII can show greater contrast on the brighter central parts. Oh, and yes of course I kept both eyes open!  

[Stormbringer]

ahh now i get it thx guys

[Stormbringer]

ok ordered 1 of each from FLO 

[LukeSkywatcher]

Shame my new 2.1x 40 bins only take 2" filters. All mine are 1.25"

[Stormbringer]

2 minutes ago, LukeSkywatcher said:

Shame my new 2.1x 40 bins only take 2" filters. All mine are 1.25"

ouch mate

[LukeSkywatcher]

It's no problem. I've never used filters with binoculars before. I was just thinking it would be nice if the new wide field bins used 1.25 filters. I knew when I bought the bins that they only take 2" filters. I didn't make a mistake or anything like that. These bins were bought just for fun really and I've been curious about them for about a year. When I say "fun", I mean something new and different to try with binocular astronomy. 

[Stu]

11 hours ago, alanjgreen said:

More filters equals darker image

True, but with good dark adaptation and a dark sky, they give better contrast and visibility of emission nebulae.

[Stormbringer]

Would these filters be any good for observing galaxies as well ?

[Stormbringer]

13 hours ago, LukeSkywatcher said:

Shame my new 2.1x 40 bins only take 2" filters. All mine are 1.25"

How are you getting on with them

They do look interesting

[Stu]

19 minutes ago, Stormbringer said:

Would these filters be any good for observing galaxies as well ?

Galaxies are a broadband of frequencies just like stars, so UHC and OIII narrowband filters are not generally useful on them. I believe that in M33 and M101 these filters can help show the nebulae and HII regionsin the aoiral arms but it is not something I have done.

[Stormbringer]

Thx mate

[BinocularSky]

On 04/05/2018 at 21:44, alanjgreen said:

use a uhc in one side and leave the other filterless.

I do the same. You can either "blink" (useful for detecting e.g. planetaries), or use both eyes and have the one view superimposed on the other for the "sheer enjoyment" effect.