what brand? ... From: Phil Jones To: Astroimaging_filters@yahoogroups.com Sent: Wednesday, May 07, 2008 6:56 PM Subject: [Astroimaging_filters] question: how...
See message 1251 in this forum. I believe that Don knows what he is talking about. Terry \--- In Astroimaging_filters@yahoogroups.com, "Richard Crisp" ... for...
I have successfully used 3nm fwhm custom scientific filters on: FSQ106 http://www.narrowbandimaging.com/ngc7000_fsq_6303_page.htm FCT76 with reducer (f/4.5) ...
I think at the time he wrote that he was only selling 6nm filters so you gotta pitch what you have to sell right? now that he is selling 3nm filters I wonder...
Richard, You are clearly one of the top authorities on the subject so I'd certainly advise folks to listen to your advice on narrowband filters, but please...
Ok Ed However it is true that he made numerous statements as to the superiority of the wider bandwidth filters several years ago versus the narrower ones and I...
Hi Richard C, were the fast lens images taken with the very narrow bandpass filters ahead or behind the lens? If behind the lens, did you also take comparative...
behind the lens in the conventional position did not take images with the filter ahead of the lens: would be happy to if there was a straightforward way to do...
Hi Richard C, I'm not so sure I agree on how a narrowband blue-shift would manifest itself as you describe. Blue-shift with angle as measured in my experiments...
... From: ssb73q To: Astroimaging_filters@yahoogroups.com Sent: Wednesday, May 14, 2008 1:34 PM Subject: [Astroimaging_filters] Re: question: how narrow is too...
Hi Here comes an example for a filter in the convergent beam: The IDAS LPS V1 and V2 filters are obviously designed to get rid of most of the Hg lamp...
Hi Richard C, IMO bench testing or comparative image testing is the only why to know for sure the effects of fast system blue-shift. Flat frames can fix...
Hi Richard C, Wolfgang's references gave me an idea on how to test the significance of an 3nm filter blue-shift imaging. Take an f2.8 image and then an f8...
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Astroimaging_filters group. File :...
Astroimaging_filters@...
May 15, 2008 1:05 pm
1950
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Astroimaging_filters group. File :...
Astroimaging_filters@...
May 15, 2008 1:06 pm
1951
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Astroimaging_filters group. File :...
Astroimaging_filters@...
May 15, 2008 1:07 pm
1952
Hello, This email message is a notification to let you know that a file has been uploaded to the Files area of the Astroimaging_filters group. File :...
Astroimaging_filters@...
May 15, 2008 1:11 pm
1953
look in the files section and you will see a folder called ray tracings there are four fast lenses uploaded to examine. look at the angles of the rays at the...
The key point Samir and others, is to look at the size of the field you are asking the lens to illuminate. If the field is small, then the off axis performance...
Hi Samir, the only issue isn't just bandpass peak shift, it's also broadening of the bandpass. Why does anyone buy a narrowband filter in the first place? To...
... That probably won't work well, if you want to use the aperture setting ring of the camera lens. These are often not good to better than 10% true aperture...
... and ... Just if you uses a Halpha emitter without a significant continuum for the flats with the Halpha filter. If you use a light source with a continuum,...
... Why do you mean with passband broadening ? With parallel light, the broadening of the passband is proportional to the wavelength shift ratio. So a 2 A...
I do believe that your reply below is getting appropriately specific. Science or pretty pics. From my own experience with 7nm and 8nm filters I would...
Hi Richard Are that all 100 mm FL lens designs ? The FL is given just for one of them as 100 mm in the title ! The measures in mm are confusing me. Isn't the...
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