From: Kevin in Fort Davis <fsm79734@gmail.com>
Date: May 24, 2015 3:37:39 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] IR Cut Filter Necessary? [1 Attachment]
Hi Stephen, I'm very glad to hear that information, especially because
of the three PGR USB3 cameras I was considering, the Grasshopper was
at the top of the list. As far as you know, has anyone in your forum
attempted to use Astro IIDC with the other USB3 camera that PGR
currently sells (Blackfly, Flea3, or Chameleon3)? I have a support
question in with PGR, as Milton had suggested, inquiring about the
minimum frame rate that those cameras can use, and whether they can
run at USB2 speeds. I don't expect to hear anything back from them
until early next week.
I value your experience, as well as the members of your forum and the
Astro IIDC forum, because they are more likely to have the knowledge
regarding which PGR cameras will work well (or at all) with Astro
IIDC. I'm not going to get that information from PGR. I think
they've tried to help me out as much as they can, but as they have
pointed out, they are not knowledgeable with astronomical imaging in
general.
If I find that PGR's USB3 cameras aren't going to work for our
application, then I'm going to need to consider their Firewire cameras
and what changes I can make to our setup that will ameliorate the
issue I'm having with FW800 bandwidth. We've had good luck in general
with their Flea3 FW800 2MP cameras, bandwidth issues notwithstanding.
To open another can of worms, what other camera manufacturers should I
be considering? Any camera I purchase should be known to work well
for solar H-alpha imaging and play nicely with Astro IIDC, be around a
1/2" chip, and around 2 megapixels in resolution.
Thanks!
-Kevin Mace
McDonald Observatory Visitors Center
On 5/23/15, Stephen Ramsden sramsden@natca.net [Astro_IIDC]
<Astro_IIDC@yahoogroups.com> wrote:
Kevin,
I hate to even break in here but in case you didnt know…
I run a forum at http://solarchat.natca.net where we have about 20-25
people currently using the USB3 grasshoppers for solar imaging. They are
all PC users as I am the only Mac user on there I think, but some of them
may have tried it on a Mac. I have heard no one find anything that could
run these cameras in native Mac. Unfortunately.
Milton’s absence has set back solar astronomy years and has virtually
eliminated the chance of getting most people under 40 interested in it…(as
they all use Macs)
Stephen W. Ramsden
Nonprofit 501c3 Director
Atlanta, GA - United States of America
sramsden@solarastronomy.org
404-543-7616
www.solarastronomy.org
On May 23, 2015, at 5:30 PM, Kevin in Fort Davis fsm79734@gmail.com
[Astro_IIDC] <Astro_IIDC@yahoogroups.com> wrote:
Thanks for those great suggestions, Milton. The FW800 hub I'm currently
using is this one:
http://www.amazon.com/NitroAV-8-Port-FireWire-Professional-Repeater/dp/B00506K4NC
<http://www.amazon.com/NitroAV-8-Port-FireWire-Professional-Repeater/dp/B00506K4NC>
and its power supply is rated at 12V/3A. When I first started having the
FW bandwidth issue (everything worked fine for nearly two years before
this problem developed), I tried swapping in the exact Kramer hub that you
mentioned, with the same result. I've also replaced all the cabling end to
end.
I have not tried running the cameras at 1624x1224 8bit. Will the image
quality not suffer at 8 bit? I will try that as soon as it stops pouring
rain.
I will ask PGR if their USB3 cameras can run at USB2 speeds and what the
minimum frame rate is. Unless I've missed it, they only specify a "frame
rate" which is presumably the fastest frame rate.
-Kevin
On Fri, May 22, 2015 at 8:58 PM, Milton Aupperle maupperl@gmail.com
<mailto:maupperl@gmail.com> [Astro_IIDC] <Astro_IIDC@yahoogroups.com
<mailto:Astro_IIDC@yahoogroups.com>> wrote:
Hi Kevin;
On 2015-05-22, at 11:46 AM, Kevin in Fort Davis fsm79734@gmail.com
<mailto:fsm79734@gmail.com> [Astro_IIDC] <Astro_IIDC@yahoogroups.com
<mailto:Astro_IIDC@yahoogroups.com>> wrote:
Milton, I probably should have included more detailed information as to
why I'm considering PGR USB3 cameras. It's not for USB3 frame rate, but
rather to get the to PGR cameras with larger physical chip sizes. We
need the image coming from the Lunt telescope to be full-disk, and it's
not quite full-disk with the PGR USB2 Chameleon and Firefly 1/3" CCD
cameras. We need the chip size to be closer to 1/2". We have two PGR
FW800 2MP Flea3 cameras with which we've been quite happy, and we use
those to show white light and hi-mag H-alpha views of the Sun. However,
because of the physical setup in the dome, our cable lengths are pretty
long (4.5m from cameras to FW800 hub, then another meter to the
computer), so it's sometimes a challenge for both cameras to be
recognized at the same time - presumably because of the long cables.
Thus, I'm afraid of adding yet another FW800 camera and long cable on the
same bus. We could restructure the physical layout of the electronics in
the dome, but with long focus 6" and 4" refractors, the cables by
necessity have to be pretty long to allow for all slewing angles.
A couple of things you can try.
1) Is the FW Hub powered or not? And if not, have you tried powering it?
Some hubs do not pass through full amperage and in edge cases you could
wind up with the cameras just barely working - which would make it flakey.
Also check to see what the voltage and wattage the power adapter delivers
is adequate for those FW Cameras (it should be 12 volts and at least 2.5
watts per camera, so around 0.5 to 1.0 amp will be fine for 2 cameras).
2) The maximum a FW 800 Cable should be is 4.5 meter when running at 800
mbps. Unless the FW Hub has repeater properties (basically amplifying the
signal), the drop in signal could be part of the problem. Something like
this:
http://www.bhphotovideo.com/c/product/431602-REG/Kramer_VS_30FW_VS30FW_3_Port_FireWire_800_Repeater_Hub.html
<http://www.bhphotovideo.com/c/product/431602-REG/Kramer_VS_30FW_VS30FW_3_Port_FireWire_800_Repeater_Hub.html>
might solve that issue. That would also give you a little more freedom in
configuration too, as you could go to 4.5 meters from camera to the Hub
and 4.5 meters from the hub to the computer too.
3) Have you checked that your cables are good? A bad cable with an
intermittent short can cause all sorts of weird issues.
4) If your running the 1624 x 1224 FW 800 cameras at 7.5 fps in 8 bit, you
should be able to run three or four of them off the same bus without any
problem. If you got to 15 fps or 16 bit per pixel, you will only be able
to run 2, there won't be enough bandwidth.
As far as cameras go, I would stick with USB 2 or FireWire 800. The issue
with is USB3 is that the camera may not run because it has minimum frame
rate speeds and might not be able to transfer frames fast enough over
USB2. PGR would have a better idea as to if their USB 3 cameras will run
at USB 2 speeds or not.
HTH..
Milton Aupperle