Can anyone explain this ?

[Vox45]

I got myself an Astronomik CLS-CCD filter for my modded Canon 1000D and while doing some tests I ran into this issue

1. I would expose for a couple of second and get this:

 

And then, for some images, I would get a reddish one :

3. then at some point I got this:

At that point I thought that it could be the clouds (we had a lot of patches of high clouds moving fast at that time)

Can anyone explain this ? I never had this issue before I put the filter in. I can remove the filter to see if the problem goes away but that would not explain what is happening

[Merlin66]

I use a 1000D with full FULL mod (both internal filters removed) and have fitted a clear clip in filter to allow focus with standard camera lenses.

I haven't experienced a similar issue/problem.

Do you cover the rear viewfinder????

 

[Vox45]

3 minutes ago, Merlin66 said:

I use a 1000D with full FULL mod (both internal filters removed) and have fitted a clear clip in filter to allow focus with standard camera lenses.

I haven't experienced a similar issue/problem.

Do you cover the rear viewfinder????

 

No I do not. You think this could come from my headtorch ? I usually turn it off when exposing but that could be it... I'll have to do some test.

I never had to cover de rear viewfinder, isnt the viewfinder blocked when the mirror is up ?

[Merlin66]

Yeah but.....

There's always the possibility of leakage, try it and see.

 

[Dave In Vermont]

My first question was to be about any nearby light-source.

I think a head-torch would qualify.

Dave

[Vox45]

That is very interesting it could have been my collegues walking around that night... I will test this.

[Dave In Vermont]

I guessed this as another person also had those same colours turn up when using the Astronomik CLS. We then discovered that when this filter was tilted to a light source, that was the result.

Try looking at the filter while holding it near a lightbulb, or similar, while tilting it.

Dave - a Filter-Nut

[Vox45]

As you are a self-described Filter-Nut, do you think that I should remove this filter when going to a really dark site (the Alpes at 3000m) ? I will spend a week there this summer and I plan to image DSO (mainly nebulae)

There will be a full moon for a part of the night, would I gain (shorter exposure time I guess) or would I lose (effect of the full moon) by removing the filter ?

[Dave In Vermont]

Scattered light from the Moon might be okay - but I feel the true answer will only be found by 'trial & error.' I've only used the CLS by Astronomik for a relatively brief period. My complaint was they turned everything that was a point-source of light - as in all the stars - blue & purple. VERY blue & purple.

Your mileage may vary, but please let us know what you find?

Enjoy your trip -

Dave

[Vox45]

Thank you, I will enjoy this trip for sure !

https://www.astroqueyras.com/index.html

As we will spend 8 days there in very good conditions I will have the time to test and see