Hello all...
Received a Hutech LPS P2 Front Filter for my 40D last Friday, only managed to use it last night.
I've attached a stack of 5x10min subs - as you can see there's a severe vignetting effect on the image which was also present on each sub.
I've asked the supplier if I can replace the front filter with the old school 67mm version for the lens end of the camera instead - hopefully that will fix any vignetting issues.
This may be peculiar to lenses and may not occur when used with scopes, but I thought I might share so that we all learn.
Any other experiences/tales of woe!?
I found this article online in which an almost identical problem occurs with a different front filter...
http://www.saratogaskies.com/articles/ha-ff/index.html
...from the conclusions in the article, looks like the problem may be caused by internal reflections.
There are 2 ways to mount the filter so that the filter glass will be 2-3mm closer or further from the sensor - that may make a difference.
Cheers
Doug
