Click here if you are having trouble logging into the forums
Privacy Policy |
Please read our Terms
of Service | Signup and
Troubleshooting FAQ | Problems? PM a Red or a Green Gu.... uh, User
Tonk
Post Laureate
Reged: 08/19/04
Posts: 4497
Loc: Leeds, UK, 54N
|
Re: How well does white balancing work for a mod-D
07/05/09 08:06 AM Attachment (8 downloads)
|
|
|
Here you go. Christain Buil has measured the Canon 350D built in IR/UV block filter and this gives 19.5% transmission at H-alpha
http://www.astrosurf.org/buil/350d/350d.htm
Meanwhile I've looked up Astronomiks transmission graphs for their filters and a replacement astronomical UV/IR filter gives 95% transmission, while the restorative filter (OWB) takes this back to 30% for H-alpha. I've superimosed the charts to allow you to see this
The H-alpha line is the second from right green spike. The grey area is human eye sensitivity by wavelength (human eyes don't see H alpha well - unless its very bright e.g. observing the sun via solar H-alpha filters). The strong red curve is the astronomical UV/IR cut filter, the paler one is the OWB restorative WB filter
|
|
4 registered and 10 anonymous users are browsing this forum.
Moderator: Charlie Hein, knuklhdastnmr
|
Forum Permissions
You cannot start new topics
You cannot reply to topics
HTML is disabled
UBBCode is enabled
|
Rating:
Thread views: 409
|
|
|
|
|
|
|
Previous
Index
Next
Flat
Edit
Reply
Quote
