m81

[alacant]

Hi everyone

Quite pleased with the detail, but can't get much colour. Here's hoping last night's moon is responsible. Knowing however how I fare with colour, it's unlikely.

Taken earlier today from around 01:00 to 03:00 when the moonlit haze became unbearable. Need more frames anyway.  One possibility for tonight  is that we have a moon filter. Tried it before, but it doesn't seem to counter the moonlight. Any experience anyone with said filter? Does it work for you? Otherwise, I think that this is going to have to wait until we get darkness again.

Cheers and thanks for looking.

eos700d @ ISO800

 

EDIT:

It maybe something to do with the debayer. Above is superpixel. Below is AHD. No ideas what they do, but whatever it is, one seems to retain colour better than the other. Starting to get some red but have now lost the background. Can't win...

 

Edited February 7, 2020 by alacant

[ollypenrice]

What does this moon filter block? The moon filter I have is just a neutral density visual filter so it blocks a percentage of the full visual spectrum, which is worse than useless for imaging.

Olly

[Galen Gilmore]

That's what I was going to ask. The moon reflects light in all spectrums (white), which means that you can't simply block out the light with a filter. Unless I'm missing something here?

[alacant]

No idea. It's labelled 'moon and skyglow'. It doesn't seem to have any effect on moonlight. The name would suggest it did.  

[vlaiv]

Probably one of these - it is just a bit more sophisticated version of CLS filter - passes 400-500 and 600-700 with a bit around 550. It's not classical moon ND type filter.

 

[wimvb]

AfaIk, moon filters (neutral density filters) are used to image/look at the moon. As Olly wrote, they dim the light to a manageable level, so it doesn't blind you. The only filters that work in moonlight are deep red filters when used at 90 degrees to the moon. As with sunlight, moonlight is scattered in the atmosphere, and the sky will be blue at 90 degrees to the moon. A red filter will block this blue scattered light and create more contrast. This is the same as using deep red filters in b/w daytime photography, and the reason why Ha imaging works during a full moon.

The filter that you have, blocks light between 550 and 600nm (if it's similar to Baaders https://www.baader-planetarium.com/en/baader-neodymium-(moon-and-skyglow)-filter.html) and is basically a light pollution filter that blocks the light from sodium and mercury lamps. 

Edited February 5, 2020 by wimvb

[alacant]

13 minutes ago, wimvb said:

blocks the light from sodium and mercury lamps. 

Thanks. Yeah, so useless for galaxies in moonlight. Misleading at best...

Edited February 5, 2020 by alacant

[wimvb]

30 minutes ago, alacant said:

Thanks. Yeah, so useless for galaxies in moonlight. Misleading at best...

Yes. There's so much marketing hype in filters that it's best to (learn to) read the spectral curves before buying. 

[alacant]

A few more frames, this time with the moon filter. It does absolutely nothing against the moon. Instead it introduces a blue cast to everything. Wonderful. Anyway, last try until it gets darker...

 

Edited February 9, 2020 by alacant

[wimvb]

The problem with imaging under light polluted skies (including moon lightl) is that you need a very long integration time to get the noise down to an acceptable level.