Filtering Galaxies

[Littleguy80]

Last night I got my first look at M81/M82. I was so happy when I found them that I actually first pumped! It was by far and away the best view of a galaxy/galaxies that I'd ever had. In fact, the difference to the views of M51 and the Leo triplet left me wondering if I'd actually seen them at all. With that thought in mind, I tried to go to M51 for a look but it was playing cloud peek-a-boo with me and it was getting late at that point. One for another night.

The point of the story is, I spent a lot of time experimenting with filters on M81/M82. I've read all the posts that say filters do nothing for galaxies plus a handful where people have seen improvements. As the saying goes, only one way to find out, so I gave the following filters a try:

• Baader Neodymium
• Baader Contrast Booster
• #82a Light Blue
• Astronomik UHC

I'm sure that list will raise some eyebrows but I've always been an advocate of exploring all the options! The #82a did very little and the UHC just made everything dark. The two Baader filters both had the effect of darkening the sky around the galaxies and making them stand out a little more. I spent a lot of time moving between filtered and unfiltered using magnifications of 38x and 50x. If I was to pick a winner, I'd say the Baader Contrast Booster at 38x made the Galaxies stand out the most. I suspect given truly dark skies then the filter would cause you to loose some detail versus an unfiltered view.

So would I recommend someone buying one of the Baader filters purely for Galaxies? No, the improvement is marginal. However, if you have one of these filters and you're under a bit of light pollution then pop it in and try if for yourself. 

Has anyone carried out similar tests and, if so, what were your thoughts on using filters with galaxies?

[John]

Interesting report

I've yet to use a filter for viewing galaxies that improves the view of the galaxy.

Nebulae - well thats a different situation entirely and the O-III and UHC filters can do a good job on those.

As someone once said, the best accessory you can buy to improve the view of galaxies is a tank full of petrol / gas to get you and the scope to a dark sky site

[Littleguy80]

Thanks John. I think you're spot on, there's no substitute for dark skies. I've been studying the light pollution maps to find somewhere close by where I can try that out. Pretty much all my eyepieces and filters have come in the last few weeks so I'm having fun trying them all out at the moment. No doubt my experimenting will prove conventional wisdom to be true but, like a child, I've just go to see it for myself to believe it 

[estwing]

Never used one on a Galaxy...TBH when I'm trying to see something so faint the last thing I want to do is place another piece of glass blocking out more light!. In fact its rare I use then now....Dark skies win every time. You can spend a massive  amount of coin trying to achieve what dark skies give you......spend it on petrol instead

[swamp thing]

Good advice above. 

The only time I use filters on Galaxies is if trying to observe extragalactic nebulae contained within them.  

[estwing]

that contast booster £60?...that's a couple of trips....just think of the views...

[Littleguy80]

1 hour ago, swamp thing said:

trying to observe extragalactic nebulae contained within them

I never even considered that as something you could with amature kit. I guess you need a large aperture scope to have much success with that?

[Littleguy80]

Just now, estwing said:

 

that contast booster £60?...that's a couple of trips....just think of the views...

 

Picked it up cheap second hand so a lot less than that but I certainly take your point

[estwing]

....come on...come join the fun....!

[estwing]

[swamp thing]

1 minute ago, Littleguy80 said:

I never even considered that as something you could with armature kit. I guess you need a large aperture scope to have much success with that?

Not all of them buddy, NGC 604 in M33 can be observed with quite modest equipment  

Give it a bash you might be surprised  

[Littleguy80]

1 minute ago, estwing said:

....come on...come join the fun....!

haha surely you can only look through one at a time  Would love a big dob. My little newt is proving a good learning scope though. I'm sure I'll appreciate a dob that little bit more after a year or so of using a smaller telescope

[John]

1 hour ago, swamp thing said:

Not all of them buddy, NGC 604 in M33 can be observed with quite modest equipment  

Give it a bash you might be surprised  

Yep - I've observed NGC 604 with my ED120 refractor. Very cool to see a deep sky object that is in another galaxy

[Stu]

1 hour ago, Littleguy80 said:

I'm sure I'll appreciate a dob that little bit more after a year or so of using a smaller telescope

Definitely. Hone your observing skills with the scope you've got before moving up to larger aperture, you will be a better observer for it I'm sure.

[Littleguy80]

4 minutes ago, Stu said:

Hone your observing skills with the scope you've got before moving up to larger aperture, you will be a better observer for it I'm sure.

Cheers Stu. I feel like I've barely scratched the surface of what can be seen with my current scope so there's really no reason to upgrade yet. I'm using Turn Left at Orion to pick targets which is a great guide and a big help with building my knowledge of what's out there to be seen. It's those little pictures in Turn Left at Orion showing "This is what is looks like in a Dob..." and reading the observing reports of those with much fancier scopes than mine that make me look forward to the day that I choose to upgrade. It's a bit like when you pass your driving test, you love your first car, no matter what it is, but look forward to the day that you can have something faster with comfier seats 

[Littleguy80]

22 minutes ago, John said:

Yep - I've observed NGC 604 with my ED120 refractor. Very cool to see a deep sky object that is in another galaxy

Amazing. Silly question but aren't you looking for a great fuzzy inside a great fuzzy?!?! What does it look like in the eyepiece?

[swamp thing]

23 minutes ago, Littleguy80 said:

Amazing. Silly question but aren't you looking for a great fuzzy inside a great fuzzy?!?! What does it look like in the eyepiece?

Err fuzzy 

Kidding, It depends on your sky obviously but it is one of the most distinguishable features to be found in any DSO. 

[John]

35 minutes ago, Littleguy80 said:

Amazing. Silly question but aren't you looking for a great fuzzy inside a great fuzzy?!?! What does it look like in the eyepiece?

M33 is large but has a low surface brightness. NGC 604 is a somewhat more condensed object close to a reasonably bright forground star and on the "outskirts" of M33. Once you know where to look it's relatively easy to see (you can say that about lots of targets though ).

Heres a little pic - probably more of a 12" under dark skies view but it gives an idea:

 

 

[alan potts]

I have used the Lumicon deep sky filter on a few galaxies and I really believe it helps a little, my understanding of the filter it is their badly named in my view street lamp filter, though I stand to be corrected. Weather filter is what I need.

[Littleguy80]

Thanks Alan. I'm glad that I'm not alone in seeing an improvement, even if it is a small one. I think the Lumicon Deep Sky filter is meant to do a similar job to the Neodymium filter that I used. I hear you on the weather filter. It'll be top of my shopping list as soon as they invent one  

[Stu]

It wouldn't surprise me if the Neodymium filter improved things a little under light polluted skies. It's a broadband filter and just cuts out some of the nastier stuff, which is actually disappearing now that white light LED street lights are replacing sodium etc.

[John]

58 minutes ago, Littleguy80 said:

Thanks Alan. I'm glad that I'm not alone in seeing an improvement, even if it is a small one. I think the Lumicon Deep Sky filter is meant to do a similar job to the Neodymium filter that I used. I hear you on the weather filter. It'll be top of my shopping list as soon as they invent one  

You might get to the point though when, for the cost of a decent filter, you could get an 8" dob which, IMHO, would give you far more improvement to galactic views than any filter can.

[Littleguy80]

12 minutes ago, Stu said:

 

It wouldn't surprise me if the Neodymium filter improved things a little under light polluted skies.

 

I have sodium lights on my road so that certainly makes sense

[Littleguy80]

6 minutes ago, John said:

You might get to the point though when, for the cost of a decent filter, you could get an 8" dob which, IMHO, would give you far more improvement to galactic views than any filter can.

You're absolutely right, John. All my filters have been bought second hand for considerably less than their full cost. I'd take that 8" dob over an expensive filter any day

[swamp thing]

4 hours ago, Littleguy80 said:

You're absolutely right, John. All my filters have been bought second hand for considerably less than their full cost. I'd take that 8" dob over an expensive filter any day

But keep some money for the tank of gas. Dark skies are going to make the biggest difference of all  

Dark skies first

Aperture second.