Memory limits?

[PartlyC]

Hi,

First:  Running 2.6.13dev7

I know this is absurd, but I have been setting up an RC for remote use in Spectroscopy.  I also attached a 72mm/F6 to the top to help with positioning, as well as to use for some simple photography and perhaps an ONAG in a pinch.  It also has an OAG .  The 72 can be used for plate solving, whereas the OAG (Aply-style) guider on the spectrometer never seems to work with that.  Probably because of my horrible seeing here.  Not asking for guiding help and the error is simple.

To see how it went, I tried using the 72mm as a guide scope.  It currently has an ASI2600MC on it (the absurd part)...  In creating the darks, it always bombed out with an out of memory exception.  Not really surprising, but it did make me wonder what the limits were on that.. my system is 32G, and it was showing 17G available at that point.  It looks like you might be bringing all the images in for the combining and bad pixel evaluation..... Also makes sense.

I got it to work fine (and actually guide pretty well) at 2x2 binning, though I had to adjust a few other things.  It did make me wonder:  What kind of memory limits do you have on this?  Just a SWAG.  If this becomes a thing I do regularly I'll put a smaller sensor on the 72, but really like the full frame option.

I am only just getting it all setup prior to leasing a nice remote pier somewhere, so not trying to optimize guiding or anything at this point.  I hope at a better location I can plate solve on the 174 guide image... as well as a lot of other things like proper mount calibration.

Just curious!  Thanks for maintaining this product and support!!

-Mike

[Brian Valente]

Hi Mike

>>>. It currently has an ASI2600MC on it (the absurd part).

well you used the word 'absurd' multiple times, so..... ;)

I think the issue is you sensor size and resulting large images. guiding is not designed with full frame 16 bit images in mind. 

I would bin that more (bin 3 or 4?) and it should be fine. Even with Bin 2 you found it worked. you could also use subframes which would also solve the problem (but at the expense of multi-star guiding)

If you have any additional questions on this, it would be better if you upload your guide and debug logs

Brian

--
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 visit https://groups.google.com/d/msgid/open-phd-guiding/e4a9c92e-bb8c-447e-b765-193ec9e80ccbn%40googlegroups.com.

--

Brian 

Brian Valente

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

[PC]

Yes... It was just my wondering what the actual memory limit might be to help me pick a camera, but its probably "it depends" versus something you can set.  No biggie.  This was just a test of the limits and thought I'd ask.  The log said "memory limit exceeded" which seemed pretty clear!  That system is offline right now.  I won't pursue this any more in any case.  I was surprised I couldn't set it to 8 bit.... thought I used to be able to have that option, but it was probably a different camera.

Thanks!!

You received this message because you are subscribed to a topic in the Google Groups "Open PHD Guiding" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/open-phd-guiding/wMYzfvEy4eU/unsubscribe.
To unsubscribe from this group and all its topics, send an email to open-phd-guidi...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i5BrcCVxoQU5JoAED6Q9GEpdAk%3DVbx058o2TKxFRF3U4Q%40mail.gmail.com.

[PC]

Oh, and I tried sub-frame, but it seemed to be pulling in the full frame anyway and just showing me the subframe part.  It had the same problem with the darks.  In fact, I believe I read in your manual that you can flip between the subframe view and the full frame view.

"'Use subframes' - For cameras that support this feature, PHD2 will download only a subframe of each guide exposure. The subframe shows
the region around the star bounded by the tracking region limits. This is useful for cameras with slow download times, allowing them to be
used more effectively for guiding. This feature applies to both calibration and guiding. During initial looping without a selected star, the full
frame is downloaded, but once a star is selected, only this small subframe is downloaded. If you are using subframes but want to see the
full frame to select a different star, just shift-click anywhere in the image display window or shift-click on the 'Auto-select star' button. Using
subframes eliminates the option for multi-star guiding, only a single star can be used with the subframe option."

This would imply it needs full frame darks...?  Or am I misreading it? Thanks!

On Mon, Sep 15, 2025 at 2:31 PM Brian Valente <bval...@gmail.com> wrote:

You received this message because you are subscribed to a topic in the Google Groups "Open PHD Guiding" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/open-phd-guiding/wMYzfvEy4eU/unsubscribe.
To unsubscribe from this group and all its topics, send an email to open-phd-guidi...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i5BrcCVxoQU5JoAED6Q9GEpdAk%3DVbx058o2TKxFRF3U4Q%40mail.gmail.com.

[Bruce Waddington]

PHD2 at this point is still a 32-bit app which is still the best trade-off for supporting the broadest range of computer systems and sensible guide cameras.  Sub-frames won't help you with this problem because, as you found, some things like auto-find and darks/bad-pix maps always use full-frame images.  Sub-frames employ region-of-interest settings in the cameras, so the full frame isn't downloaded.  That's why it's a useful feature for people trying to reduce USB traffic and download times. Binning the camera will work in your case but you need to set the binning through the profile-wizard and not do anything that will revert it to being un-binned.

Regards,

Bruce

[Dale Ghent]

Weeeeeeellll, about that "best trade-off" part.

Every major vendor of contemporary guide cameras do offer both 64bit
SDKs and ASCOM drivers. Yes, some of the older and certainly the
older+more niche cameras lack 64bit SDKs, ASCOM drivers, or both. But
bear in mind that producing a 64bit PHD2 does not necessary exclude the
continued and parallel production of a 32bit PHD2 that permits Uncle Bob
keep using his modified Philips TouCam guide camera that he made 20
years ago. Same goes for mount and rotator drivers.

All contemporary CPUs are fully 64bit internally now and 32bit operation
is more of a compatibility mode within that than a 2nd physical
characteristic of the system. 64bit apps enjoy better memory transaction
performance and gain access to certain classes of CPU instructions that
aren't available to 32bit apps. Then there is the ability to use these
guide cameras with ever-increasing pixel counts without hitting these
walls.

I think it would be quite fine to start  working on a 64bit variant that
would release in parallel with the existing 32bit one. Folks can choose
and, eventually, the number of downloads for the 32bit version will wane
to the point of being pointless to maintain. I bet there are a bunch of
those legacy camera drivers that have zero users these days, but of
course there are no stats to back that up.

-Dale

> <https://groups.google.com/d/msgid/open-phd-guiding/e4a9c92e-bb8c-447e-b765-193ec9e80ccbn%40googlegroups.com?utm_medium=email&utm_source=footer>.

>
>
>
> --
> Brian
>
>
>
> Brian Valente
> astronomy portfolio https://www.astrobin.com/users/bvalente/
> --
>
> You received this message because you are subscribed to a
> topic in the Google Groups "Open PHD Guiding" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/open-phd-guiding/wMYzfvEy4eU/unsubscribe.
> To unsubscribe from this group and all its topics, send an
> email to open-phd-guidi...@googlegroups.com.
> To view this discussion visit
> https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i5BrcCVxoQU5JoAED6Q9GEpdAk%3DVbx058o2TKxFRF3U4Q%40mail.gmail.com

> <https://groups.google.com/d/msgid/open-phd-guiding/CAJa45i5BrcCVxoQU5JoAED6Q9GEpdAk%3DVbx058o2TKxFRF3U4Q%40mail.gmail.com?utm_medium=email&utm_source=footer>.

>
> --
> 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 visit

> https://groups.google.com/d/msgid/open-phd-guiding/1566ba35-6c23-4ce2-8bd9-0ac501659f96n%40googlegroups.com
> <https://groups.google.com/d/msgid/open-phd-guiding/1566ba35-6c23-4ce2-8bd9-0ac501659f96n%40googlegroups.com?utm_medium=email&utm_source=footer>.

[Bruce Waddington]

That's all being looked into and it will probably come to pass when we think it makes sense. Obviously, it complicates the build and end-user support aspects of the project.  In the meantime, people have plenty of better choices for suitably configured guide cameras.

Bruce