“Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt Mission” is a paper describing the camera that has been feeding us pictures of Pluto.
How does it compare to a Canon, Nikon, or Sony? The thing weighs 10.5 kg and consumes 7 watts of power. A Nikon D810 weighs about 2 kg with a pro lens and has a 2 amp-hour battery at 7 volts. The Nikon battery lasts for about two hours of heavy use so the power consumption is roughly comparable.
Ralph looks through a 658mm lens at a fixed aperture of f/8.7. Nikon makes a nice 600mm f/4.0
The Nikon D810 can take a 7000 x 5000 pixel image in an instant using a CMOS sensor (go Sony!). Ralph captures 5024 x 32 pixels at a time using a CCD sensor, purchased from E2v, an English company. What if you don’t want a little ribbon photo? The spacecraft sweeps through a range of attitudes (spinning, basically) until a picture with a more normal aspect ratio is obtained.
Wikipedia says that the whole mission is supposed to cost about $700 million, about 50,000X the cost of a Nikon D810 and 600/4.
My understanding is that a big difference between probe cameras and regular cameras is that the detectors have to be radiation-hardened. Apparently the gamma rays out there are really bad for pixels.
Not only bit sensor and camera must be RAD-hard but also camera and glass need to be protected from space dust while moving at solar system – escape velocities. Sure the price would come down if middle-class people could send their personal Pluto probes.
I doubt that we would get very good pictures of Pluto by setting the exposure timer on a Nikon D810 and hurling it toward outer space with our arms.
Ralph is one of two cameras on New Horizons. The other is LORRI (pdf). This is a 1Kx1K imager attached to a 8″ telescope. This is the camera that produced the famous sepia-toned image of pluto with the prominent “heart”.
The sensors on the spacecraft must be more light-sensitive than those on earth. Even the sun is a dim light source when you’re 3.7 billion miles away from it.
> The telescope is a 2630 mm focal length, f/12.6 Ritchey—Chretien design
I don’t think Nikon makes SLR lenses this big.
How much did Nikon D810 cost in 2006?
Yep, that’s the cost of doing business in space. Radiation hardening, dynamic range, sensitivity to 1/1000 the amount of sunlight on Earth, extreme thermal tolerances, being able to work without human intervention for 10 years, extreme vibration during liftoff, being made in a quantity of 1, all contribute to the cost.
Note that the lens will have to be very well-corrected, because it has to bring red, green, blue, and infrared to the same plane of focus.
Zeiss makes, or made, a 350mm f5.6 for Hasselblad , the Tele-Superachromat. I have no idea how much the retail on this lens is, but I found a dpreview.com post that shows an old listing price of $37K for a used one on eBay. Add in a custom housing, custom design etc. the price for such a lens for space use could easily be $100K at a bare minimum.
Really though, the cost is for shipping and delivery, not the camera cost 🙂
Indeed, Deadprogrammer is right. The launch towards Pluto happened in 2006, a potential comparison should be done vs a photography machine sold in 2006.