Orion StarShoot FAQ
From SkyInsight
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Basic Troubleshooting for a Dead Camera
Q: How can I tell if my StarShoot is dead?
A: [Craig Stark] There are 2 basic options:
- dead camera (a trip back to Orion will get you a new one)
- software / computer issues.
Since 2 doesn't involve sending the camera back, there are a few things we can do to make sure it's not that.
- Download Nebulosity -- www.stark-labs.com Yes, Essentials will run the camera just fine, but I have no idea what kind of connection error checking goes on in it. Since I wrote Neb, I know what it might tell you pretty well. Install it. You'll be running the "demo" version but it'll work just fine for the tests
- Connect the camera. Hopefully, you get your USB chime.
- In Neb, on the right side, pull down Orion StarShoot. Does the status bar (bottom left) say it connected or did an error pop up?
- Set the offset to, say 120 and the duration to 1s. Aim the camera into your desk and hit Preview. All zeros as you move the mouse across the screen or do you get anything. Any errors come up? If you get something other than zeros, just aim it away from the desk surface and repeat. Higher numbers? All zero? Histogram (black box beneath sliders) show anything?
- Find another machine, preferably a desktop with a USB2 port or a laptop with an external card (PCMCIA) USB2 port and lather, rinse, repeat. When doing so, make sure to specifically tell Windows NOT to connect to Update, NOT to try to find the driver on its own, and manually point it to the driver (you can use /Program Files/Nebulosity/StarShootDS_Driver). Same results?
If all that gives squat, yes, you've got a dead cam.
Cooling
Power Supply for Cooling
A: [Michael Garvin] As you know, the camera will come with a 12 volt cigarette lighter (type) adapter. Orion sells a 12v power supply under observing aids. You can find similar units at auto supply stores and places such as Walmart. At home, you can us a 110v ac to 12v dc converter like a pyramid power supply. There is always the option of using a 12v battery and adding an outlet or making your own adapter. All the camera needs is .5 amps using a 5.5 x 2.5 jack (center positive). When considering the size of battery or supply, your computer will be the largest energy gobbler.
Determining of the TEC is wired correctly
Q: Initial problems noted came about from several of the TECs being wired backwards, so they would heat rather than cool the CCDs. What is the symptoms of the TEC being wired backwards?
A: [Craig Stark] Here's the way to view it -- you want the CCD cold, right? The TEC pumps heat from one side to the other. Pumping heat from the CCD makes it cold, but that heat needs to go somewhere, right? It goes to the case where it is radiated out to the outside air. So, yes, the CCD will get cold and the case get warm if all is working just fine (BTW, that is why there are the fins on the case -- the case is a "heatsink").
You'll also know very quickly taking images if the TEC is working. You can see the noise drop rapidly when you plug the TEC in. Were it wired backwards (again, just a small handful of cams had this), the noise would go up rather than down (to the point at which you'll "white out" the image).
IR Filter
Q: Does the StarShoot Camera come with an IR Filter?
A: [William Behrens] The camera comes with an IR filter.
The ir filter is not a bifringment/filter made of standard schott glass. It is a coated dichloric. IT will not soften your images. It is removable so that you can put an light polution filter in its place if you wish. Also if you have another IR filter you would rather use then you can.
You can take images without the IR filter and discard the luminance information for a semi b/w image. We made it so you have the option.
Q: Are you saying using the IR filter is semi-necessary for planets and DSO's? It seems weird because with my 20D everybody is spending$$$ to take the IR filter out. I'm a bit confused on when to use and not to use the IR filter.
A: [Shevill Mathers] Yes, it must seem a bit confusing, however, they are talking about two very different camera types, one a Star Shoot USB CCD and the other a digital SLR ?(CMOS sensor ) which is being modified for a particular purpose (they want the red H-alpha wavelength) and images that will be processed accordingly.
It is usual to have an infra red blocking filter in place for astro use with B&W & Colour web/CCD cameras - otherwise the colour balance will be out of whack and the infra red wavelength will give you bigger (bloated) star images because infra red focuses way out of where the normal visible light componets (RGB) focus.
I have a particular Kodak scientific colour CCD USB camera which should be IR filtered as a matter of course - but it is improved by adding a good quality (Baader) IR blocking filter, the colours in normal light are more accurate. Generay speaking colour CCD canmeras have a built-in IR Blocking filter in front of the CCD, whereas B&W do not because as they are generally modified surveillence cameras, they need to 'see' in the dark - with IR illumination.
Hope this helps a bit and others will add their comments to either correct me or fill in the gaps. But Yes, you need an IR Blocking filter for planetary and normal light deep sky.
[John Burt] With the DSLR's eg Canon 300d, 350d, 20d etc the factory IR filter also blocks the Hydrogen alpha wavelength so common in red nebulosity, so most astro-imagers with DSLR's remove this and (hopefully) get a marked increase in sensitivity on emission nebulae. With the factory filter removed most people then either replace the filter with a cut-to-fit UV-IR filter, or use a screw-in UV-IR filter in the optical path. With my home filter-removed 300D I use a baader UV-IR filter, but still get a red haze over everything if I do not use a custom white balance (I believe this is due to the way the digic processor in this camera interprets the raw data).
USB Cable Maximum Length
The maximum length of a USB cable is 16 feet or about 3 meters. While it may be possible to go beyond that length, the signal will degrade. This length limit can be overcome by using a repeater, most commonly known as a USB Hub. The most important thing is to get a USB hub with a power connection, otherwise it too will suffer signal degradation. Adding a USB hub allows you to extend the cable length another 16 feet (15 meters). USB hubs come with various number of ports and the number you'll need depends on what other devices you need to connect at the same time.
Basic Troubleshooting
John Wunderlin
- If you're getting funny lines across the bottom of the image, it's probably because you're using USB 1.1.
- If you get an odd interference pattern, your USB controller is probably not compatible with the camera.
- Don't buy a powered hub to solve problem #2
- The Belkin USB 2.0 PCMCIA works, BUT, you must use the external power plug in addition to the card.
RAW - What's So Great About RAW?
A: [Craig Stark] On the OSS, RAW is a 16-bit dump of exactly what was on the CCD. When you convert it to color on the fly and when you convert it to color after the fact, you run through the same process. The file gets 3x as large as a result, as it turns into 16 bits per color per pixel.
Digital camera's RAW's are larger, as noted, because the alternative is JPG compressed. You'll never get an image straight off the OSS -- RAW or color -- that has been JPG compressed.
RAW is better than converting on the fly because (some of these noted):
- Files are 1/3rd the size
- You don't debayer hot pixels because you
- Did your dark subtraction on the RAW or
- Did what you really should do which is Bad Pixel mapping (this results in less noise in your final image relative to dark subtraction).
- You open yourself up to a broader range of possibilities (e.g., the above noted Bad Pixel mapping, Colors in Motion, all sorts of neat things).
- When you look at the captured histogram you're seeing your actual data. You know exactly how close to saturating your pixels you got / how many you saturated. Your final image comes down to the quality of what you get of the CCD and the RAW format shows you that.
AutoGuiding and Guiding
Q: Can the StarShoot do a stack and accumulate so it can guide itself?
A: [Craig Stark] The StarShoot will guide a scope while another camera integrates long exposures. If you do the "stack and accumulate" you are sending guide commands between frames. Thus, if you can do 15s without star trailing, you can only do 15s exposures. If you use two cameras, one can guide while the other takes longer (e.g. several minute) exposures. If you're using one camera, you usually might as well simply run unguided and take 15s exposures, letting the stacking (align and combine) happen after the fact.
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Bad Pixel Mapping in Nebulosity
Submitted by Matt
These are the steps I've been using taking the BadPixel Mapping route:
- Set Neb color acquistion to RAW, then select 'save preferences'. Do this once (set it and forget it). :^)
- Map a Bad Pixel Map: (I've only done this once) Take a *bunch* of dark frames with similar duration, settings that are representative of your capture session. Use aluminum foil over the top to ensure no light leaks (at any wavelength). Use 'fixed combine of images' to combine all your darks into a single image. Save this file as a DarkImage file Then 'make bad pixel map' from that dark. Save the results as a BadPixelMap image.
Then each time I've captured images in RAW, I ran thru these steps:
- Processing->BadPixels->Remove BadPixels: RAW Color
- Select your BadPixelMap then all the RAW images you wish to use. (badpix_images)
When done, with the above step, You will run Batch De-Mosaic on your freshly-processed images. (color_badpix_images)
When done, I then do the Alignment & Stacking. My default, is to choose Align & Combine:Drizzle
It sounds like a lot but it's not really and I like the results. I'm still figuring all this out and I'm quite pleased with what I can capture and the resultant images....
Glossary of Terms
Bias Frames
Bias frames are very short exposures that give an idea of readout noise. It is better to take them with the lens covered, but when you make them in the dark, the stars won't hurt the result as their exposure is only a small fraction of the picture exposure time.
