Camera Lenses and Testing

I don't have any fancy optical bench equipment, so "testing" is a practical issue: how well do the images look when I use this lens? It never really occured to me until reading Covington and Reeves.

There are two main things to look for when testing a lens. First, is it any good at all; i.e., do the star images focus fairly well across most of the field of view. Second, how much does it have to be stopped down before the images as the edge of the field of view are sufficiently sharp.

My 50-mm f/2 Pentax SMC (used with my Pentax A3000) shows aberrated images when used wide open. I haven't adequately tested it to find the minimum f-stop where the images look good, but at f/4 the star images are quite sharp all the way to the edge of the 35-mm frame. My 50-mm f/1.4 Takamura (used on my Pentax Spotmatic) is another matter....

I took a set of test shots of Lyra ranging from 5 seconds to 120 seconds. All where done from third-floor front porch here in Forest Hills, NY (Queens, NYC). Although the conditions were good (very clear skies, low humidity) for New York City, on the Bortle scale this would rate an 8 or 9. Visually, I could see down to about magnitude 4 at the zenith with averted vision, magnitude 3 with direct vision.

Rather than keep you in suspense, lets just say I was diappointed with the lens' performance. Still, this is preliminary; I need to take a second set of pictures to try to find which part of the optical system was at fault because I was using the lens with a 2X tele-extender and had a Skylight 1A filter in place. I doubt the filter did anything, but I don't think it is coated, so some of the reflections may be due to the filter.

Severe aberrations affect both images. With the lens at f/1.4 (photo at f/2.8 due to the tele-extender), Vega looks like a brush-stroke. The streak across the middle of both appears to be a reflection but may be a roller mark from the developer. Note that it appears to arc in opposite directions on the two images. Although the second image appears much better, a close inspection of Vega (see below) reveals in interesting, not-quite-symmetric, 6-pointed star. I suspect I have some interesting reflections off the lens' iris which has 6 blades.

There are other aberrations visible at the edge of the frame. At first, they might look like field rotation but I was polar aligned more than good enough for this short exposure. Plus, they become very apparent in the close-up shown below: even the airplane's lights are distorted!

This particular lens combination is definitely a loser for me. I'll probably try again without the tele-extender and with a multicoated Skylight filter (as well as without any filter) to see how the lens performs with settings from f/1.4 to f/4. This camera, the Pentax Spotmatic, is a fully-manual camera which makes it more attractive than my newer Pentax A3000 which requires batteries to hold the shutter open; i.e., the "B" setting is not a mechanical shutter. Unfortunately, they are not lens compatible. The Spotmatic takes the older Pentax screw-mount lenses while the A3000 takes the more common bayonet mount. If it weren't for that, I would just take the newer lens and put it on the older camera.

One thing which is nice to see is that I can easily make out Lyra. The limiting visual magnitude near the zenith was about 3.5; with averted vision it was about 4.5. Near the center of image, there are stars as faint as magnitude 8.

References

• Astrophotography for the Amateur, Michael Covington, copyright © 1999, published by Cambridge Univesity Press.
• Wide Field Astrophotography, Robert Reeves, copyright © 2000, published by Willmann-Bell, Inc.

DIY: Dew Heaters

Okay, the first thing is that unless you are skilled with a soldering iron, a sewing machine, and happen to have more time than money and maybe also have access to the supplies to make these, you probably want to just fork over the money to buy a commercial solution.  Far be it from me to discourage you, but I have made both my own heater control circuit and my own heaters.  It takes time.  For me it took a lot of time.  After using them for about three years, I bought Dew Not heaters and A Thousand Oaks controller .   I'm not going to show you want I did, because it was a hack using a CMOS 4093 as the timer for the pulse-width-modulation and a relay.  The relay give nice audible feedback in the dark, but they really aren't designed for that sort of repetitive open/close cycle.  Here are some links to sites where the folks actually know what they are doing.

• Wiring
  • Wire Gauge and Current Limits has some basic information on what size wire will carry what size current load. You want to know this in building the different sized heaters. For example, to make the 1-1/4 inch size heaters, you can use 28-guage wire which will carry over 200 mA.
  • Wire Resistance has some more information like the above link, including information on (surprise) wire resistance and current capacity.
• Home-Made Heaters
  • Mark Kaye's Heaters shows how he built some very nice heaters. I've made some heaters using a variation on his technique.
  • Ron Keating's Heaters use 330-ohm resistors wired in parallel to get whatever power rating you are aiming at. I've made on heater suitable for 2-inch eyepieces using this technique, but don't much care for it because the heater is stiff. But it does work. I also used denim rather than duct tape and had to do a bit of sewing.
• Heater Controllers
  • Dewbuster is a controller made by Ron Keating that is thermostatically controlled. This is nice because it reduces power consumption by keeping the heater a fixed amount above ambient rather than just heating at a constant power rating.
  • Don Clement's Controller is another one which uses automatic temperature control to avoid overheating and reduce power consumption. This one is strictly DIY; Don's site has schematics and a PCB layout.

DIY: Make Your Own PCBs

No, that's not those poisonous things in electrical transformers, in this context PCB means printed circuit board.

• Electronic Design Software
  • XCircuit is a schematic design/drawing tool, a la XFig. It's not so slick as a lot of Windows tools and takes some getting used to, but it's free and it make nice drawings. Additionally, it can export netlists for use with other tools, e.g. PCB (see below). There is also a LWN review (Linux Weekly News) from May 2000 if you want a quick overview.
  • PCB is a printed circuit board layout tool. There is also a SourceForge project page which seems to be a bit more up-to-date. When you are done, you can print them out onto tranfer film to make your own PCBs. PCB also has an LWN review from June 2000. The chief problem I've encountered is the difficulty of making custom elements.
  • gEDA is a suite of tools for Electronic Design Automation. There is overlap with the above tools, although gEDA current recommends use of PCB until they have their own tool.
• Resistors
  • The Secret Lives of Pots. This is an interesting look at potentiometers and how they work. Nothing profound, but it's still kind of fascinating if you've ever wondered how they were constructed.
• Making PCBs
  • Techniks makes "Press-n-Peel PCB Blue Transfer Film" for etching your own PCBs. They have a couple of different versions of the stuff. Reviews are mixed. I ordered some (Aug 2003) and tried them for a few projects.  They take some practice to learn how to get them to stick properly to the copper-clad board.  I lost patience and gave up.

DIY: Webcam modifications

Here are some links to webcam modifications that I found useful.

• Ashley Roeckelein Astronomy Pages has several webcam modifications and case designs well worth looking over.

Eyepiece Projection

Recently we purchased T-adapter and T-ring along with the variable adapter for eyepiece projection imaging. The real intent was to start out taking a series of lunar photos at Newtonian focus using an 35 mm SLR. The 1200 mm focal length of our Newtonian should put an image of the (full) moon approximately 10–11 mm across at the film plane; plenty big enough to make some nice enlargements and yet small enough that we can take pictures even though the telescope is on a Dobsonian mount.

Alas, we discovered what many others have found—the camera will not come to focus due to insufficient in-travel on the focuser. The cure is to obtain an low-profile focuser. Time to spend another USD$80 or so.

However, since we already had the tools for eyepiece projection, I decided to try it by taking a couple of rolls of film of Jupiter. I was a little worried about vibrations due to the mirror slap of the SLR but figured it wouldn't hurt. So, I used 3 rolls of Fuji Superia Xtra ISO 400 film and took multiple frames at each exposure. My effective focal ration was near f/41, so I used the table from the back of Michael Covington's Book and shot frames from 1/4 second all the way out to 1/125 second. For each shot, I refocused using the logic that I couldn't get it wrong all the time. The ground-glass focusing screen in my Pentax Spotmatic made it tough to get the focus, but I could generally tell I must be close because Jupiter's moons would become pinpoints and I could make out a little banding on Jupiter.

The first two rolls had identical exposures and I had one of them pushed one stop. The last roll was the one which extended to 1/125 second, and I had it pushed two stops. Every exposure was repeated 4 or 5 times. Again, the idea was that I hoped to have at least one good frame in the lot.

Now the bad news: I have exactly two frames that have anything remotely resembling Jupiter. The remainer are indistiguishable from a badly out-of-focus picture of a distant light bulb. Clearly, the mirror slap is a bigger issue than I realized, at least at f/41. The two "good" frames (and I use that term quite loosely) were taken at 1/125 second. Oh, and did I mention that I took the film to a professional shop where I had it all developed, printed, and a set of contact sheets done for USD$80? Ouch!

All hope is not yet lost for our original project, taking moon pictures. At f/8, the effects of mirror slap should be less noticable. Plus, except for the smaller crescent phases, there should be enough light that, with moderately fast film, the exposure should be very short hopefully "freezing" the slap. That's what I think saved the two frames which came out showing at little of Jupiter's banding.

The moral: for planetary shots, you probably want a camera with mirror lock up.

Focus Testing

Robert Reeves suggests testing the focus of your lenses as the infinity mark cannot always be trusted. This isn't necessarily because the manufacturer was sloppy; certain long focal-length lenses may significantly affected by temperature and at some temperatures they will focus beyond infinity (Buzz Lightyear, take note).

I decided to do a quick test of the 50-mm f/2 lens on my Pentax A3000. The test involves making a Hartman mask for the lens and shooting a set of star trails, each with a slightly different focus. The first step was to print a small label with lines at intervals of about 2-mm which I could attach to the camera lens where the distance calibration marks are located. This allows me to carefully turn the focus ring in steps of about 1-mm. I focused, per Reeves' suggestion, starting from the closer settings toward infinity, stepping 1/2-mark without ever backing up to insure that the gear mechanism is fully engaged with no backlash.

I used Lyra as my target area simply because it was roughly overhead at the time which allows me to easily point without having any local street lights shine into the camera. Since my camera does not allow multiple exposures on the same frame, I used the "hat-trick" though in my case it was a black fleece glove. The first exposure was for 60-seconds. I then covered the lens with the glove and adjusted the focus ring. I then took a 30-second exposure and repeated. Making the first exposure longer than the others allows you to easily tell from the resulting photo which end is the starting point.

Below is a close-up of one section of the print showing Vega and Epsilon Lyrae. What I expected to see was a series of double trails for each star. Each pair would be closer together than the previous pair with them eventually converging into a single trail and possibly spreading apart again. Since I only see one trail (the double trail for the upper star is because Epsilon Lyrae is a double; there really are two stars there), my tentative conclusion is that focusing is not very critical for a 50-mm lens.

However, I'm not quite willing to stand on that just yet. Among other things, I'm not sure about the orientation of the Hartman mask so it is possible that the reason that I don't see two trails is because they are co-linear instead of being parallel; i.e., maybe I need to rotate the mask 90-degrees and try again.

References

• Wide Field Astrophotography, Robert Reeves, copyright © 2000, published by Willmann-Bell, Inc.

Gradient Removal with Picture Window Pro

I purchaseed Picture Window Pro 3.1 after seeing a large number of people on APML mention using it for image processing. I've only been using a couple of weeks at the time of this writing, but so far I am quite happy with it. Picture Window Pro is happy to do a lot of tings with 48-bit images that Photoshop does grudgingly (if at all). It also seems to run faster as it should: it is nowhere near as feature rich as Photoshop as it does not need all of the graphics arts tools.

Here is a short version of how I processed my constellation portrait of Hercules. Some of the steps here involved trial-and-error; I'll save you tedium of reading through that, but will point out where I had to try more than once.

Step Zero: The Raw Image

Obviously, the starting point is the raw image. In my case, I scanned my slide using VueScan for Linux and saved the raw image. I purchased VueScan in part because I heard good things about it and in part because I wanted a comparison of using it instead of one of the SANE tools (e.g., xsane, scanimage, xscanimage, etc.). I've concluded that I could have happily continued using SANE without any problems. More on that elsewhere.

Step One: Synthetic Sky Glow Maps

Hercules was high enough in the sky that I really didn't expect to have any problems with sky glow, yet the film clearly shows some glow on the western side. Fortunately, Hercules contains no significant nebulosity nor does the Milky Way appear in the field of view. This makes it possible to use the simplest of all possible gradient removal methods, a wide Gaussian blur (Transformation -> Blur). I used a 100-pixel radius Gaussian blur which completely obliterates any stars.

Why do we do this? Well, in some sense this step is like a dark frame that CCD imagers take. The question is, in the absence of any stars, what does the image look like? The problem is that there is light reaching the camera that has nothing to do with the stars and which is not internal (like CCD dark current).

Step Two: Gradient Removal

Once you've created a gradient using the Gaussian Blur, it gets removed by using the Composition tool (Tranformation -> Composition). From this tool, you can select which two images are to be combined and how. Subtract the blurred image from the original. I chose to subtract 90% of the blurred image. I knew I wanted to subtract less than 100%, but how much less was a matter of trial and error. I started out subtracting only 50%, but by the time I finished my latter steps (i.e., a midtone stretch) the gradient from the sky glow had reappeared.

Note that the image appears somewhat dark. Subtracting out the sky glow results in darkening the entire image but that's okay, we can "fix" that up by some contrast stretching later.

Step Three: Contrast/Level Adjustment

Here I chose to use Picture Window Pro's Transformation -> Gray -> Levels and Color menu as the quick way to get the effect I wanted. You should be able to do the same thing by adjusting the curves. From the Levels and Color menu, I boosted the midtones by about 65% but made no adjustments to the color saturation. Quite frankly, it already looks pretty colorful to me. The 65% figure was a matter of trial and error and you could pick something different based on taste.

Step Four: Unsharp Mask

Quite frankly, at this image scale, the effect is irrelevant. An unsharp mask should really be done at the image scale where you plan on displaying the final results. I.e., if you unsharp the original image (scanned at 2400dpi) and then reduce the image by a factor of 10-15 (like this one), you've wasted your time. Of course, you might not have spent much time, but the point is that the unsharp mask is a small effect at this image scale. If you plan on making a print at full scale, then the step is worthwhile.

In my case, an unsharp mask with a radius of 2 and boost of 100% did a nice job of tightening up the image. Radii larger than 3 resulted in stars starting to spread out again. Since the result had no effect at the resolution used on this page, I've skipped the image. As an FYI, you should really do the unsharp mask at the display resolution since a rescaling destroys the results.

Step Five: What did I do?

I have no idea. I did an extra step before saving the image, but I don't know what it was. There is very little change to the final result, so it was obviously not very important. And it definitely does not show up at the resolution of these images.

Summary

Below are the images in sequence showing the progression. Note that once the midtone-stretch is complete, there is no significant change to the image at this resolution. In fact, except for the full scale image, the effects of the unsharp mask are insignificant. I said it earlier but I'll say it again: you should really do the unsharp mask at the display resolution since a rescaling destroys the results.

SANE vs VueScan

SANE, Scanner Access Now Easy, is the Linux framework for interfacing with scanners. There are a number of tools for doing the actual scanning. The most primitive one is called scanimage. It is a command-line tool which, for my purposes, is perfect. In its default mode it yields a raw scan image with no corrections. Since this is what you generally want for processing your images, you don't really need to buy VueScan. VueScan will take care of some things for you that scanimage won't such as compensating for film base color. For slides this is irrelevant, but for negatives it's a nice feature, at least for normal daytime shots. Since astrophotos are likely to need color balance changes anyway, there is little motivation to do a partial job in the scan step.

However, some of my contentment may be due to ignorance. In particular, the documentation of SANE's Epson driver and that of VueScan leave a bit to be desired. It is unclear to me how much control over the scanner I have while it is still doing the scanning in analog mode.

I mentioned that scanimage is a command-line tool. After a bit of work, I put together a shell script which will automatically scan specific locations on the strip holder. I can now run that, launch it into the background, log out and go away while the scanning takes place. VueScan has a batch mode which is similar but requires you to keep the GUI up and running. VueScan also seems to keep the scanner active between scans even when it is idle.

The short of it is that VueScan doesn't really give me anything that scanimage doesn't for astrophotography. However, if you are not comfortable with the command-line on Linux, VueScan gives a nice interface that does make scanning very easy.

SBIG Cameras on Linux

I've been fighting with Windows XP for a long time trying to get everything working satisfactorily. As usual, easy things are easy, but hard things are impossible. Sigh. I am no fan of Windows, but Linux has simply not had the tools to get up and running quickly. But after wasting yet another night with having to find and download missing DLLs (this time, msstdfmt.dll which according to some web sites comes with XP but I can't find it on my CD-ROM and according to others it's part of the Visual Basic Runtime but the Microsoft download for VB 6.0 SP5 didn't include it and their web site indicates it won't be included with Vista---did they remove it early?) I've launched back into trying to get things working.

First, XEphem is a very good tool for starting. So is KStars, though XEphem is oriented more toward science. And the INDI platform is analogous (if more less pervasive and having fewer drivers) to ASCOM. So all I really need is to get the camera to boot and demonstrate that I can aquire images. Okay, there's really more. What I'm aiming at is something like ACP.

The title of this section is "SBIG Cameras on Linux" which is a bit grandiose since I have exactly one SBIG camera, an ST-7XE NABG along with their color filter wheel CFW-8A.

# udev's /sbin/firmware_helper won't work for this since the driver
# doesn't set up the correct files.  There's probably some way for
# that to be hacked here but I don't know how....

BUS=="usb", ACTION=="add", \
SYSFS{idVendor}=="0d97", SYSFS{idProduct}=="0001", ENV{DEVICE}!="", \
RUN+="/sbin/fxload -D $ENV{DEVICE} -I /lib/firmware/sbigucam.hex"

BUS=="usb", ACTION=="add", \
SYSFS{idVendor}=="0d97", SYSFS{idProduct}=="0002", ENV{DEVICE}!="", \
RUN+="/sbin/fxload -D $ENV{DEVICE} -I /lib/firmware/sbiglcam.hex"

BUS=="usb", ACTION=="add", \
SYSFS{idVendor}=="0d97", SYSFS{idProduct}=="0003", ENV{DEVICE}!="", \
RUN+="/sbin/fxload -D $ENV{DEVICE} -I /lib/firmware/sbigfcam.hex -t fx2"

# This is the ID presented once the firmware has been loaded.
BUS=="usb", ACTION=="add", \
SYSFS{idVendor}=="0d97", SYSFS{idProduct}=="0101", \
MODE="0666", SYMLINK+="sbig.%n"

PAR_ERROR CSBIGCam::EstablishLink(void)
    PAR_ERROR res;
    EstablishLinkResults elr;
    EstablishLinkParams elp;

        /* For reasons unknown at present, a single attempt to establish the
           link may fail.  But it seems to always work within 5 tries.  Be
           generous and give it 10. */
        for (int i = 0; i < 10; i++) {
            res = SBIGUnivDrvCommand(CC_ESTABLISH_LINK, &elp, &elr);
            if ( res == CE_NO_ERROR ) {
                m_eCameraType = (CAMERA_TYPE) elr.cameraType;
                return res;
            }
            cout << "failed to establish link, will try again" << endl;
            //            sleep(1);
        }
        return res;
}

278 roland> ./testapp 
Creating the SBIGCam Object on USB...
Establishing a Link to the USB Camera...
Link Established to Camera Type: ST-7
Taking light image on USB...
Saving compressed image...
Closing Devices...
Closing Drivers...
SUCCESS
Hit any key to continue:

extern void get_info(void)
{
	GetDriverInfoParams gdip;
	gdip.request=DRIVER_STD;
	SBIG(CC_GET_DRIVER_INFO, &gdip, &gdir0);
	if (parms.info) driver_info("Highlevel driver:", &gdir0);

	gdip.request=DRIVER_EXTENDED;
	SBIG(CC_GET_DRIVER_INFO, &gdip, &gdir0_2);
	if (parms.info) driver_info("Lowlevel driver:", &gdir0_2);

	EstablishLinkParams elp;
	elp.sbigUseOnly=0;
        {
            int i;
            for (i = 0; i < 10; i++) {
                SBIG(CC_ESTABLISH_LINK, &elp, &elr);
                if (elr.cameraType==NO_CAMERA) {
                    fprintf(stdout, "No camera found!\n");
                    exit(1);
                }
            }
        }

	GetCCDInfoParams gcip;
	gcip.request=CCD_INFO_IMAGING;
	SBIG(CC_GET_CCD_INFO, &gcip, &gcir0);
        if (!gcir0.readoutModes) {
            fprintf(stderr, "No readout modes!!  WTF!!\n");
            exit(1);
        }
	if (parms.info) ccd_info0("Imaging camera:", &gcir0);

	gcip.request=CCD_INFO_TRACKING;
	SBIG(CC_GET_CCD_INFO, &gcip, &gcir0_2);
	if (parms.info) ccd_info0("Guiding camera:", &gcir0_2);

	gcip.request=CCD_INFO_EXTENDED;
	SBIG(CC_GET_CCD_INFO, &gcip, &gcir2);
	if (parms.info) {
		printf("Camera system:\n");
		printf("Bad columns: %d\n", gcir2.badColumns);
		printf("Imaging ABG: %d\n", gcir2.imagingABG);
		printf("Serial number: %s\n\n", gcir2.serialNumber);
	}

	gcip.request=CCD_INFO_EXTENDED2_IMAGING;
	SBIG(CC_GET_CCD_INFO, &gcip, &gcir4);
	if (parms.info) ccd_info4("Imaging camera", &gcir4);

	gcip.request=CCD_INFO_EXTENDED2_TRACKING;
	SBIG(CC_GET_CCD_INFO, &gcip, &gcir4_2);
	if (parms.info) ccd_info4("Guiding camera", &gcir4_2);

	ReadOffsetParams rop;
	rop.ccd=CCD_IMAGING;
	SBIG(CC_READ_OFFSET, &rop, &ror);
	if (parms.info) offset_info("Imaging offset:", &ror);

	rop.ccd=CCD_TRACKING;
	SBIG(CC_READ_OFFSET, &rop, &ror_2);
	if (parms.info) offset_info("Guiding offset:", &ror_2);

	SBIG(CC_GET_LINK_STATUS, &rop, &glsr);
	if (parms.info) {
		printf("Linked: %d\n", glsr.linkEstablished);
		printf("Address: 0x%x\n", glsr.baseAddress);
		printf("Camera: %d\n", glsr.cameraType);
		printf("Communications count: %ld\n", glsr.comTotal);
		printf("Failed communications count: %ld\n\n", glsr.comFailed);
	}

	set_temp();
	get_temp();
} 

extern void SBIG(short cmd, void *parms, void *results)
{
	GetErrorStringParams gesp;
	GetErrorStringResults gesr;

        /* For reasons unknown, the camera may not establish a link on the
           first try.  It seems to always work within 5 attempt, but we are
           generous and give it 10.  Other commands should work just fine
           without retry once a connection has been established. */
        int i;
        for (i = 0; i < 10; i++) {
            gesp.errorNo=SBIGUnivDrvCommand(cmd, parms, results);
            if (cmd != CC_ESTABLISH_LINK) {
                break;
            } else if (gesp.errorNo == CE_NO_ERROR) {
                break;
            }
        }

	if (gesp.errorNo) {
		int i;
		i=SBIGUnivDrvCommand(CC_GET_ERROR_STRING, &gesp, &gesr);
		if (i) {
			fprintf(stdout,"Command 'CC_GET_ERROR_STRING'"
					" failed!\nThe error string will"
					" be printed anyways;"
					" don't trust it.\n");
		}

		fprintf(stdout, "\a\aError: %s\a\a\n", gesr.errorString);
	}
} 

281 roland> ./st7ctl --info
Highlevel driver:
Version: 04.43
Name: libsbigudrv Ver 4.43-LINUX,
Request Limit: 1

Lowlevel driver:
Version: 00.10
Name: libusb system driver,
Request Limit: 1

Imaging camera:
Firmware Version: 02.41
Camera: 0x4
Camera: SBIG ST-7 Dual CCD Camera
Mode count: 10
Mode ID, Width, Height, Gain (e-/ADU), Pixel width (microns), Pixel height (microns)
0 765 510 02.41 000009.00 000009.00
1 382 255 02.41 000018.00 000018.00
2 255 170 02.41 000027.00 000027.00
3 765 0 02.41 000009.00 000009.00
4 382 0 02.41 000018.00 000009.00
5 255 0 02.41 000027.00 000009.00
6 765 510 02.41 000009.00 000009.00
7 382 255 02.41 000018.00 000018.00
8 255 170 02.41 000027.00 000027.00
9 85 56 02.41 000081.00 000081.00

Guiding camera:
Firmware Version: 02.41
Camera: 0x4
Camera: SBIG ST-7 Dual CCD Camera
Mode count: 2
Mode ID, Width, Height, Gain (e-/ADU), Pixel width (microns), Pixel height (microns)
0 190 162 01.38 000013.75 000016.00
1 95 81 01.38 000027.50 000032.00

Camera system:
Bad columns: 0
Imaging ABG: 0
Serial number: 02073118

Imaging camera:
Frame transfer: 0
Electronic shutter: 0
dumpExtra: 5

Guiding camera:
Frame transfer: 0
Electronic shutter: 0
dumpExtra: 0

Imaging offset: 804
Guiding offset: 962
Linked: 1
Address: 0x0
Camera: 4
Communications count: 18
Failed communications count: 0

Temperature regulation on?: 0
Regulation frozen?: 0
Setpoint (Celsius): 26.827324
Percent power: 0.000000
CCD temperature (Celsius): 27.436655
Ambient temperature (Celsius): 25.000000