Does a SCT need an IR filter for imaging or video?
Posted 18 April 2013 - 10:22 PM
Posted 18 April 2013 - 10:24 PM
Posted 18 April 2013 - 11:36 PM
Posted 19 April 2013 - 03:06 AM
I don't use IR-block filter for my SCT imaging even though I use focal reducers [lenses] - under test IR light contributes noticeable to image density - maybe 30%. Blocking IR effectively needs a longer exposure and in brief [video] exposures we need all the light we can get.
That is my question. Thanks for a response in advance.
Posted 19 April 2013 - 10:04 AM
It is my understanding that it does not unless you are using lenses (focal reducers, field flatteners, etc.).
Nope, not even if you are using reducers--as almost all folks doing video do. They are helpful for refractors in keeping star bloat down.