Guide cam to Image cam ratio

[Bruce Ahler]

Hi,

Just a quick question. I saw where a guide cam to image cam, as/pixel ratio of 3:1 was recommended. Does this hold true when using an OAG? My ratio, using a OAG is near 1:1.

Bruce A.

[Brian Valente]

Hi Bruce

Keeping the ratio of guide image scale to imaging camera image scale to 3:1 or lower is a general recommendation for all setups

with an OAG, it's still true, but you are starting at 1:1, so you would have to go out of your way to get higher than 3:1. I suppose it's possible with a huge pixel camera, but you are most likely safe there

--
You received this message because you are subscribed to the Google Groups "Open PHD Guiding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to open-phd-guidi...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/d250f517-43b5-44ac-9193-c170af8a6e5dn%40googlegroups.com.

--

Brian 

Brian Valente

astronomy portfolio https://www.astrobin.com/users/bvalente/ 

nature portfolio brianvalentephotography.com 

other astronomy https://www.brianvalentephotography.com/astrophotography/ 

[Bruce Ahler]

Thanks, Brian. I’ve just stated using an OAG and am getting decent results with a 1:1 guide to imager ratio. So I’ll stick with what I’ve got. 

Bruce A. 

Sent from my newish, but not so smart iPhone. 

On May 21, 2023, at 11:28 AM, Brian Valente <bval...@gmail.com> wrote:



To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i63mYz5Q20qWRx2zXZcT4Haswidaesj-iiT%3DkX3NXKreQ%40mail.gmail.com.

[Brian Valente]

Sounds good

Fyi the advantages of an oag are more about reducing differential flexure in addition to a good focal length 

To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/511E5ACD-48E7-4AC0-8A93-7F05F4F3BDDF%40gmail.com.

[Bruce Ahler]

That’s why I went with an OAG. I’m using a Meade, 805mm fl refractor and was having flexure problems. 

Thanks again

BruceA. 

Sent from my newish, but not so smart iPhone. 

On May 21, 2023, at 12:40 PM, Brian Valente <bval...@gmail.com> wrote:



To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i5wPrUsDujP4Zt4ckLjQn7wu5tzgPetf9G92ijFKyamcw%40mail.gmail.com.

[oliv...@gmail.com]

…And better SNR due to a much larger telescope aperture (than a small guide scope). Better SNR = more precise centroid calculation = better guiding.

Olivier 

Le 21 mai 2023 à 18:40, Brian Valente <bval...@gmail.com> a écrit :



To view this discussion on the web visit https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i5wPrUsDujP4Zt4ckLjQn7wu5tzgPetf9G92ijFKyamcw%40mail.gmail.com.