Best filters for Venus?

[King]

Hi!

The below Venus image was taken on boxing day and though I wasn't expecting very much at this early stage, I'd like to at least maximise my chances at some cloud detail.

Now according to this thread and some other sources, a "wratten BG39" is the way to go due to needing to cut IR without also cutting UV. (I used a normal IR filter attached to a DBK21 for this.) To be honest though, I'm struggling a bit with that as I've checked the listed sites that apparently supply them and got a bit confused with the only listed "BG39" being a Schott (I don't know if that's a "wratten"). Either I need specific links to the relevant filters for a 1.25 or pointing in the direction of any alternatives, preferably stand-alone 1.25 filters.

Another problem is the advice to use a W47 as I gather that owing to its light blocking intensity, it's useless with smaller apertures (such as my 5")?

Also is there any constructive criticism on the image I need to take on board? For one I think I need the histogram a bit lower...

[arbacia]

For Venus clouds with monocrome DMK I use a Baader U-Venus filter (it is narrowband ultraviolett filter centered at 320nm) However, be aware that it need a terrific seeing to get some results as the UV is heavely affected by atmospheric turbulences.

I am not sure, but I think U-filter is beyond the sensitivity of a DBK21. Look for a violett planetary filter

Patricio

[King]

Well I do have the option of a DMK41 so I can consider it for that.

[arbacia]

Is for the 127 & DMK 41? If so, the U-Venus filter is so dark. Expect expositions of about up to several seconds (!)

Patricio

[King]

Yep it's for that telescope. Just as well you told me that detail, thanks!

[michaelmorris]

I have had some promising results with a Lumicon #47 violet filter Lumicon #47 Violet Filter 1.25 | Telescope Accessories | Rother Valley Optics on a mono-chipped Toucam pro II through an 8" LX200 (picture below).

One day I'll splash out on an Astrodon UV Pass filter. Astrodon Astronomy Filters - UVenus Filter

These have >90% transmission in the UV band.

[smt1988]

I have had some promising results with a Lumicon #47 violet filter Lumicon #47 Violet Filter 1.25 | Telescope Accessories | Rother Valley Optics on a mono-chipped Toucam pro II through an 8" LX200 (picture below).

One day I'll splash out on an Astrodon UV Pass filter. Astrodon Astronomy Filters - UVenus Filter

These have >90% transmission in the UV band.

great image that one

[MarsG76]

Astrodon UVenus... that one gave me great detail and exposure times were 1/15sec...

dont cut corners with alternative filters because you will end up paying twice... and using a lower quality filter because it's cheaper will only slow your progress...

this is what I managed with UVenus as blue, IRcut as green and IRPass685 as red...