Where can I get a 48 mm Kenko red filter?

[michaelmorris]

I'm trying get hold of a Kenko 48mm red (R1/R64) filter. These are supposed to well as a hydrogen alpha filter for a DSLR when used with an IDAS filter. I can't find one anywhere in the UK or EU. Any ideas?

Sent from my Nexus 7 using Tapatalk

[ronin]

Questions: Kenko 48mm red (R1/R64) filter.

Cannot see a Kenko 48mm filter, seem to be 46 or 49.

What is R1/R64?

I can see a US site with an R1 filter and with an R64 filter. Do you mean R1 or R64 ?

Any idea what the filter characteristics are? As in what wavelengths are passed, is it a glass coloured bandpass or a norrow pass, interference pass. I half guess it's is just a nice red glass filter.

[ronin]

Can find a Hoya R60 equivalent at £36 from Edmund Optics.

Update:

Hoya and Kenko are very much the same, they are like Skywatcher and Celestron whre they are owned by one company, the Hoya's are said to be slightly better, often the holders are better, little diference on the filters.

According to Hutech Astro Products they list "Kenko R1(R60)".

Making me think that the Kenko R1 is the same as the R60 (Hoya).

The R64 passes less of the Red then the R1 so should be the better option, just cannot find one.

[michaelmorris]

Questions: Kenko 48mm red (R1/R64) filter.

Cannot see a Kenko 48mm filter, seem to be 46 or 49.

What is R1/R64?

I can see a US site with an R1 filter and with an R64 filter. Do you mean R1 or R64 ?

Any idea what the filter characteristics are? As in what wavelengths are passed, is it a glass coloured bandpass or a narrow pass, interference pass. I half guess it's is just a nice red glass filter.

Sorry, I meant the R1/R60

[michaelmorris]

I strikes me that decent 2" red planetary filter may perform the same job as the Kenko R1 filter.  But where can I get a single red good (low reflectivity/high transmission) 2" planetary filter - they all seem to come in sets.

[ronin]

Edmund Optics

Actually the R64 looks better, just rare as hens teeth.

R60/R64 Comparision

The Red filter in EO says R60 equivalent.

I assume that R60 = 600nm and that 600nm is the 50% transmission wavelength.

[Merlin66]

The 49mm was a standard size for the ol' DSLR lens...

The outside diameter of the 49mm still fits inside a 2" focuser.

I occasionally use a 49mm filter with a 49/48 stepper ring. Works well.

[laser_jock99]

Consider also the B+W 091 filter. Very high quality German made with Schott glass and AR/AR coated (and sadly a high price to match!)

http://www.ebay.co.uk/sch/i.html?_nkw=091%20red%20filter&_sacat=0&_odkw=29%20red%20filter&_osacat=0&_trksid=m194&ssPageName=STRK:MEFSRCHX:SRCH

They come up second hand on e-bay from time to time. Snap them up if you see one.

They are very close (if not the same) as the Lumicom Ha filter http://www.lumicon.com/store/p/88-72mm-Night-Sky-Hydrogen-Alpha-Filter.aspx which also costs a lot of money. I have picked up the big 82mm B+W 091 on E-bay for £10 or so, this size will even fit very wide angle lenses or some telephotos.

[Merlin66]

Surplus Shed are having a 55% sale....

There's a 2" red filter..http://www.surplusshed.com/pages/item/m2628.html.

[Dom543]

I don't know, if anyone is still interested in this old thread. But for reference, Lumicon makes standard photo filters in 1.25" and 2" (M48) formats. Here is one link to a US retailer but I am sure that there are Lumicon dealers in the UK or EU.

http://handsonoptics.com/index.php?keyword=lumicon+filter&main_page=advanced_search_result&search_in_description=0

(It seems that Lumicon charges 3x more than standard photo filter sellers for the convenience of the astro size enclosures.)

Color photo filters are usually referenced by their Wratten numbers. The Kenko R1/R60 is Wratten #25 (Red). Kenko R64 is Wratten #29 (Deep Red).

Clear Skies!

--Dom