05-12-2012, 10:09 PM
[quote name='popo' timestamp='1336856673' post='18164']
The double linear resolution is a best case, but not an unrealistic one to be attained some of the time. If you are working deep in the red or blue regions where there isn't significant green sensitivity left, you have just lost the use of 75% of the sensor area.[/quote]
Yes/no/maybe <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />. I'd use a filter for use with monochrome only with monochrome, and only apply a filter to a colour image after the fact, in post-processing IOW. This means the loss is less, theoretically anyway <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.
That's very true, but only valid when mounting such a filter to the lens (or camera), prior to taking the shot.
Also true, but the effect of diffraction increases exponentially with aperture, which means that one may only gain a stop effectively, or thereabouts.
I guess in your case, for astronomy, it makes a difference. It may also well be cheaper than a camera especially designed for astronomical purposes <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />. I was considering normal photographic opportunities, however <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.
Kind regards, Wim
The double linear resolution is a best case, but not an unrealistic one to be attained some of the time. If you are working deep in the red or blue regions where there isn't significant green sensitivity left, you have just lost the use of 75% of the sensor area.[/quote]
Yes/no/maybe <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />. I'd use a filter for use with monochrome only with monochrome, and only apply a filter to a colour image after the fact, in post-processing IOW. This means the loss is less, theoretically anyway <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.
Quote:One the CA point, as mentioned in a previous post, it doesn't matter if a lens has either form of CA if you are looking at a sufficiently narrow part of the spectrum. Other parts can't interfere if they're not significantly being passed.
That's very true, but only valid when mounting such a filter to the lens (or camera), prior to taking the shot.
Quote:Diffraction limiting is no more a constraint than for colour. Like increased MP counts in general, you don't need to have 100% use of it all the time. This could give more capability to hand to use when conditions allow.
Also true, but the effect of diffraction increases exponentially with aperture, which means that one may only gain a stop effectively, or thereabouts.
I guess in your case, for astronomy, it makes a difference. It may also well be cheaper than a camera especially designed for astronomical purposes <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />. I was considering normal photographic opportunities, however <img src='http://forum.photozone.de/public/style_emoticons/<#EMO_DIR#>/biggrin.gif' class='bbc_emoticon' alt='' />.
Kind regards, Wim
Gear: Canon EOS R with 3 primes and 2 zooms, 4 EF-R adapters, Canon EOS 5 (analog), 9 Canon EF primes, a lone Canon EF zoom, 2 extenders, 2 converters, tubes; Olympus OM-D 1 Mk II & Pen F with 12 primes, 6 zooms, and 3 Metabones EF-MFT adapters ....