Baader LRGB CCD filter set

[TheThing]

A set of the Baader LRGB CCD filters arrived through my door early this week from FLO. This is the cheaper of the two sets FLO supply at £73 plus p+p.

As usual, the service from FLO was excellent - thoroughly recommended.

The set came in FLO's trademark double jiffy bag which was more than enough to protect the contents.

Inside, the filters are in a clear plastic bag with their own individual jewel cases and a rather informative set of graphs showing their performance. Sadly, the graphs mean little to me, so some explanation would maybe have been helpful? Something for Baader to consider?

The filters are the usual well made items I expect from Baader. No loose elements in the surround, spotless and pristine. There are no identifying features on the filters, but the share the same design as other Baader filters I have owned. The set includes a Red, Green and Blue filter, as you would expect, and an IR Cut filter to use for the Luminesence channel and to stack with the other three.

I had read some suggestions that these filters were merely coloured glass, but close examination appears to support the fact that are properly coated optics and not just cheap, get 'em out quick jobs.

They have threads top and bottom, as would be expected, to allow stacking and the screw in action is very smooth - unlike some cheaper filters I have used.

Currently, I'm waiting on a manual filter wheel from Peter (Psychobilly), a true gent and top geezer. Also, I need a clear night with no other commitments to try them out, so I will report further in due course.

I am pleased to note that Jupiter now clears the trees at the top of the hill around 11ish, so no guesses what my first target will be.

All in all, very pleased and certainly worth the price from the best retailer. Imaging with them will be the proof though. Watch this space.

TheThing.

Sent from my iPhone using Tapatalk

[riklaunim]

I had read some suggestions that these filters were merely coloured glass, but close examination appears to support the fact that are properly coated optics and not just cheap, get 'em out quick jobs.

They are colored glass type filters and not interference filters with interference coatings

They even mark on the spectral charts what type of filter is used (from the Schott, Wratten and other lists)

[FLO]

They are colored glass type filters and not interference filters with interference coatings

Yes, they are also referred to as 'absorptive' filters. They absorb the unwanted spectral bands whereas dichroic filters are reflectance filters, they reflect unwanted light, hence thier mirror-like finish.

I think Hugh is referring to the way some dealers (in an attempt to sell cheap dichroics) dismiss the budget Baader LRGB filters as 'simple painted glass'. They are considerably better than that and have the advantage that they are less likely to cause abberations from light reflecting back into the optical chain.

HTH

[riklaunim]

Yes, they aren't painted, as the whole glass mass is colorized. I use few filters of such type for luminance planetary shots. From Wratten #12 (a.k.a visual yellow) up to RG1000 infrared for Venus and RG850 for Moon shots at f/10.

(bit odd that nobody wants to sell RG and alike filters nicely mounted in 1,25" cells... and they are very cheap).

BTW. Baader has a name collision

[StevieDvd]

So are these filters OK for imaging, particulary on a budget?

[FLO]

(bit odd that nobody wants to sell RG and alike filters nicely mounted in 1,25" cells... and they are very cheap).

It is marketing, people perceive dichroic filters as premium. It is true that the 'best' filters from the likes of Baader, Astronomik and Astrodon are all dichroic as that is necessary for precise control of the colour spectrum. In some instances, they also transmit approx 1/5th more light. For astro-imagers not undertaking scientific research and working to a budget (most of us!) a well-made died-in-the-mass absorptive filter with planeoptically polished glass is probably the best option.

[FLO]

So are these filters OK for imaging, particulary on a budget?

Yes

Posh/expensive dichroics are nice but don't let anyone tell you they are essential for good results.

[Ben Ritchie]

In some instances, they also transmit approx 1/5th more light

I'm surprised it's that high? Would appear to be enough to make a significant difference to exposure times?

[FLO]

I'm surprised it's that high? Would appear to be enough to make a significant difference to exposure times?

In most instances it is not

[lukebl]

So are these filters OK for imaging, particulary on a budget?

Presumably they must be, as they are marketed for that purpose.

Also, I have a set myself. They seem OK, but haven't had many opportunities to test them properly.

[Ben Ritchie]

In most instances it is not

Ok, don't quite follow - I'm just surprised, that's all, don't have an axe to grind either way (purely visual, can't afford imaging any more), but we can spend lots of money on faster 'scopes, reducers, more sensitive CCDs and the like in search of elusive S/N, so potentially taking a big hit in filter transmission seems quite significant. 1/5th more light is quite a bit.

edit: are we talking best dichorics vs. poor absorption filters, or general purpose?

[FLO]

Dealers often quote 1/5th more light transmission when selling premium dichroics but I suspect that is only when comparing the best dichroics against the worse absorptive. I feel sure it must also depend on the colour tested.

[Ben Ritchie]

Thanks for clarifying Steve, that makes much more sense. I would completely agree with "Posh/expensive dichroics are nice but don't let anyone tell you they are essential for good results."

[riklaunim]

There is a zilion ideas for RGB filters. One is the technology, second are the pass-bands. Some Astrodon as well as QHY/Orion RGB filters cut a lot of yellow to limit LP. Baader "premium" LRGB nearly doesn't cut it out. Astronomik has more triangle-like band shapes, and IDAS Type 4 even has small blue transmitance for the red filter to make violet color... and if you stack them with IR-passing filter (instead of ir cut) they will allow you to do a RGB in IR (like Astrodon NIR set)...

But also going cheap check this out: - Dichroic Colour Filters UQG Optics from Stock, Order Online - you can get cheap RGB set or cheap filter combinations for planetary imaging (cheap UV Venus filter, infrared filters), or even put together your own Schuler photometric set from those "industry" filters Disadvantages - they may have halos, they may have less transmission, or they may be annoying to mount in a 1,25" cell...

Something for astronomers with McGyver skills to experiment with

For some filter curves go to:

- http://astrosurf.com/buil/filters/curves.htm

- http://www.astroamateur.de/filter/

- http://www.sonnen-filter.de/

[FLO]

So are these filters OK for imaging, particulary on a budget?

I hope he won't mind me mentioning this but I have just heard Astronomy Now are featuring one of davy999's images in thier 'Picture Gallery' this month. It is an image of M42 made using the Baader absorptive filters mentioned in this thread

I feel sure the image is somewhere here on SGL, I'll post a link when I find it.

HTH,

Steve

[StevieDvd]

I hope he won't mind me mentioning this but I have just heard Astronomy Now are featuring one of davy999's images in thier 'Picture Gallery' this month. It is an image of M42 made using the Baader absorptive filters mentioned in this thread

I feel sure the image is somewhere here on SGL, I'll post a link when I find it.

HTH,

Steve

Thanks for the update, I grabbed a set of Astronomik LRGB filters from a sale thread here.

But even with the best gear some of us will still fail to match the experienced imagers who used just the basic gear

[pmlogg]

Another advantage of the Baader LRGB is that they are supposed to be parfocal with the Baader narrow band filters. The Baader narrow bands are narrower than most others, barring the more expensive Astrodons.

[riklaunim]

Another advantage of the Baader LRGB is that they are supposed to be parfocal with the Baader narrow band filters. The Baader narrow bands are narrower than most others, barring the more expensive Astrodons.

But not those Baader LRGB described in this thread

[Whippy]

But not those Baader LRGB described in this thread

No, but the set of these filters I owned were parfocal on their own, just not with the Baader Ha filter I owned.

Tony..