strange filter effect

[alacant]

Hi everyone. With the filter, the blue histogram is moved to the left (as viewed in dss) and the star halos diminish. NP, I like the effect as it's easier to process, but can't see why it's happening. I wonder if too many filters have been removed from the camera and-or the uv or ir is converted to visible by the sensor? It's a canon 700d. TIA and clear skies.

[SkyBound]

Hi,

If both filters were removed from the camera, which is a full spectrum mod, and you were not using an IR filter then that could be your issue, especially if using a refractor scope.

the reason the second filter is left in the camera is to give the needed IR cut when doing digital imaging, so if your camera is full spectrum modded, then you just need to use a seperate IR filter in the imaging train somewhere, or if you also get a bit of light pollution, then consider the Astronomik CLS CCD light pollution clip in canon filter, they are superb...

[alacant]

Ah. OK. Here's the info from the guy who did the camera modification:

Quote

 

The hot mirror is the colour corrector filter which is good for daylight photography but, unfortunately, it's responsible for blocking H-alpha radiation. For that reason, this filter is removed in any type of modification.

The AA filter is the front filter where the autoclean function goes. This filter has the function of slightly blurring the image to avoid any moiré effect. The AA filter has built in UV and IR protection so it should be enough to avoid star bloating and chromatic aberration but those also depend on the type of telescope or lens used. 

The hot mirror is the colour corrector filter which is good for daylight photography but, unfortunately, it's responsible for blocking H-alpha radiation. For that reason, this filter is removed in any type of modification.

By adding an extra UV-IR filter you are reducing the chances of the light not aligning correctly in the optical train. With your current optics, that extra protection is making a difference. 

 

In my case it loos as though although the AA filter is still there it could do with a bit of extra help  (?).

Cheers and clear skies