Hi, I calculated the shim distance for the Canon camera filter replacement when using 3mm fused silica, 0.0066". Regards, Richard ... outside ... the ... good ...
Hi, I measured the transmission of the 2" Orion SkyGlow filter, the chart can be seen in file Light Pollution filters.xls in file folder Filter tests. I have...
Very nice work! In moderate to severe light-pollution, (I have the latter), the region of the spectrum with STRONG l-p emissions and continua, (546nm thru...
Hi George, thanks for the reply and correcting my conclusion. That's why I like the method of public postings, the peer review that brings out the truth. The...
Hi George, one other comment, the Baader tends to be a bit weak on at the SII line, 672-3nm compared to the Orion. Fast optical systems blue shift a filter's...
Quickly, the issues involved in how an interference filter will perform is extremely task-and-site specific, involved (i.e. what is recorded by your device),...
Richard, the Canon UV/IR cut filter you're referring to was the rectangular filter in front of the 350D CMOS sensor? I just got the same Canon350D with the...
Hi George, I see you found the link that I would have given you. There's only one problem with removing the filter completely, fixed lenses will not focus at...
Going into business to re-mod Canon DSLRs? You know I seriously thought about it. But considering the requirement that a filter must be meticulously clean, I'd...
Hi George, when I was a bit younger I would have done my Canon conversions myself in a heartbeat. I can't remember all the microsoldering circuit boards I...
Hi, a few people have asked me about the uniformity of interference filters across the filter aperture. Visually my higher quality filters look very uniform,...
Wow. Moisture integration! I said I would get closeups of my filters, so I did. Completely unretouched small jpgs... A NEW 1000 Oaks 2" broadband filter at...
The "fused-silica" graph is virtually a straight line, from the UV into the IR. This is what I'd prefer to install in my 350D. Does the sensor need protection...
Hi George, very interesting photos! Thanks for sharing them with us. Just this weekend I saw a new filter that looked visually like what you showed in your...
Hi Richard Crisp, good to hear from you, I was wondering where you were. I heard from a Baader filter distributor that Baader has the intention to supply a...
I performed some tests recently on my ancient Dream Machine camera using the Photon Transfer method pioneered at JPL by Janesick and Elliott beginning in the...
I got that LP1 filter (1st pics) just last week. It cost $159US. Ugly enough, I had to use another retention ring that was much wider. Yesterday I confronted...
Hi, I received a private email a couple of days ago asking about the transmission behavior on broadband (light pollution) filters in fast optical systems,...
Hi George, I know that most of the filters sold by Orion are made in either Japan or Korea. IMO most of the low cost filters that find their way on to our...
have you tried the scotch tape test to test for adhesion of the coatings? that's a common test done in the semiconductor industry ... From: ssb73q To:...
Hi Richard Crisp, sorry, but I won't be doing that test on my filters. Let us know how the scotch tape test works out on yours. VBG Seriously, I suspect that...
well unfortunately the testing business often involves destructive testing as well as non-destructive testing Richard, if you want to be thorough you want to...
Hi Richard, I have my ball-peen hammer ready, send me your filters. VBG Regards, Richard M ... testing as well as non-destructive testing Richard, if you want...
besides the scotch tape coating adhesion test, a cross sectioning and staining would be interesting to see how many layers the cavities are. also basic...
One would hope they start off with perfectly (or adequately) flat & parallel surfaces. I now seriously doubt, however, that any of my filters (Lumicon, Orion,...
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