Re: A "best" f/number to image?

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• Because the NexImage uses a CCD device with 5.6um pixels, f/20 in any telescope will just meet the Nyquest sampling rate for the camera. You may want to go a
Message 1 of 6 , May 1 4:48 AM
Because the NexImage uses a CCD device with 5.6um pixels, f/20 in any
telescope will just meet the Nyquest sampling rate for the camera.
You may want to go a bit longer as the Bayers mask increases the
effective pixel size of the NexImage. I'll post the derivation of
this number if you are interested, I wrote it up on a post on
CloudyNights and I'll dig it out.

Philip

--- In neximage@yahoogroups.com, "gstrumol" <gstrumol@...> wrote:
> I've been wondering about what is the "best" f number to take photos
> at, and would like your thoughts. Here is the issue as I see it (and
> I may be totally wrong).
• Thanks Philip - since you ve done the calculations, (grin) what about f-30? ( I need that to get nice-sized planetary images with my little AP 130 f-6.) Does
Message 2 of 6 , May 1 5:45 AM
Thanks Philip - since you've done the calculations, (grin) what about f-30? ( I need that to get nice-sized planetary images with my little AP 130 f-6.) Does going too long create imaging problems?
Peter
NYC

In a message dated 5/1/2006 7:49:44 AM Eastern Daylight Time, blandp11@... writes:
Because the NexImage uses a CCD device with 5.6um pixels, f/20 in any
telescope will just meet the Nyquest sampling rate for the camera.
You may want to go a bit longer as the Bayers mask increases the
effective pixel size of the NexImage.  I'll post the derivation of
this number if you are interested, I wrote it up on a post on
CloudyNights and I'll dig it out.

Philip

• Because the pixels are square, you d need f/28 diagonally. :)
Message 3 of 6 , May 1 6:54 AM
Because the pixels are square, you'd need f/28 diagonally. :)

rightquiet@... wrote:
> Thanks Philip - since you've done the calculations, (grin) what about
> f-30? ( I need that to get nice-sized planetary images with my little
> AP 130 f-6.) Does going too long create imaging problems?
> Peter
> NYC
>
> In a message dated 5/1/2006 7:49:44 AM Eastern Daylight Time,
> blandp11@... writes:
>
> Because the NexImage uses a CCD device with 5.6um pixels, f/20 in any
> telescope will just meet the Nyquest sampling rate for the camera.
> You may want to go a bit longer as the Bayers mask increases the
> effective pixel size of the NexImage. I'll post the derivation of
> this number if you are interested, I wrote it up on a post on
> CloudyNights and I'll dig it out.
>
> Philip
>
>
• In a message dated 5/1/2006 10:05:32 AM Eastern Daylight Time, wrhamblen@comcast.net writes: Because the pixels are square, you d need f/28 diagonally. :)
Message 4 of 6 , May 1 8:47 AM
In a message dated 5/1/2006 10:05:32 AM Eastern Daylight Time, wrhamblen@... writes:
Because the pixels are square, you'd need f/28 diagonally.  :)
Thanks, very much ... I think. You are being serious, right? Does the :) symbol mean you are joking, or being friendly?

Peter
NYC
• That would be great. What could we search in Cloudy Nights to pull the article up? Gary ... photos ... (and
Message 5 of 6 , May 1 4:20 PM
That would be great. What could we search in Cloudy Nights to pull the
article up?

Gary

--- In neximage@yahoogroups.com, "blandp11" <blandp11@...> wrote:
>
> Because the NexImage uses a CCD device with 5.6um pixels, f/20 in any
> telescope will just meet the Nyquest sampling rate for the camera.
> You may want to go a bit longer as the Bayers mask increases the
> effective pixel size of the NexImage. I'll post the derivation of
> this number if you are interested, I wrote it up on a post on
> CloudyNights and I'll dig it out.
>
> Philip
>
> --- In neximage@yahoogroups.com, "gstrumol" <gstrumol@> wrote:
> > I've been wondering about what is the "best" f number to take
photos
> > at, and would like your thoughts. Here is the issue as I see it
(and
> > I may be totally wrong).
>
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