Mars rover camera project manager explains 2MP camera choice
A number of factors led to the use of 2MP sensors in the main imaging cameras used on NASA's Mars rover, Curiosity, says the project manager responsible for their development. The slow data rates available for broadcasting images back to Earth and the team's familiarity with that family of sensors played a part, says Malin Space Science Systems' Mike Ravine, but the biggest factor was the specifications being fixed as far back as 2004. Multi-shot panoramas will see the cameras deliver high-res images, he explains, but not the 3D movies Hollywood director James Cameron had wanted.
'There's a popular belief that projects like this are going to be very advanced but there are things that mitigate against that. These designs were proposed in 2004, and you don't get to propose one specification and then go off and develop something else. 2MP with 8GB of flash [memory] didn't sound too bad in 2004. But it doesn't compare well to what you get in an iPhone today.'
|The 34mm (115mm equiv.) Mastcam from the Curiosity rover - developed by Mike Ravine and his team at Malin Space Science Systems.|
The first consideration when choosing a sensor was the amount of data it would produce.
There are three ways for Curiosity, to broadcast data back to Earth - but it's only the UHF transmitter that can be used for transmitting the amounts of data required for sending back images. 'The UHF antenna transmits to two spacecraft orbiting Mars, which relay the results back to Earth. That's where most of the data is coming from. It gives us on the order of 250 megabits per day, and that's got to be shared between a bunch of instruments, so there's not much bandwidth for the cameras.' Ravine explains.
Another factor was that the same sensor had to meet the needs of four different cameras (MAHLI, the two Mastcams and MARDI, the camera tasked with capturing the rover's descent to the planets' surface). 'Everything in a project like this is sensitive to price and risk, both real and perceived. The cameras differ in terms of their optics, but by building them around a single platform, we didn't have to re-test and qualify each of them separately. This makes them more dependable and less expensive than if you have to do it four times.'
'We developed all four cameras around a common architecture so the choice of sensor was hedged across all of them. We wanted to be able to capture high frame rates, particularly with the descent camera.' he explains. MARDI, the downwards-pointing 'descent camera' had just a two-minute descent to the planet's surface, so a high frame rate was essential. The KAI-2020 chip was the smallest Kodak made capable of 720p HD video. 'We also looked at a 4MP sensor but it would have run around half as fast. And the state of CMOS sensors wasn't credible in 2004. They're an interesting option now, but they weren't then.'
|The initial thumbnail image from the MARDI descent camera, showing the heat shield dropping away, just before the final descent begins. Click here to see a video of the heat shield falling away, based on these thumbnail images.
Image Credit: NASA/JPL-Caltech/MSSS
The other advantage of the Truesense Imaging chips was the team's familiarity with their behavior. 'We've built-up decades of cumulative experience of working with Kodak and now Truesense interline sensors. We know how to clock them and drive them - they're a very easy CCD to drive,' says Ravine. A similar level of confidence was needed for the cameras’ memory, he says: 'the flash we ended up using was because we had a lot of radiation test data for it.'
| The full-resolution image, released August 8th, giving a clearer idea of what the 2MP cameras onboard the Curiosity rover with be capable of.
Image Credit: NASA/JPL-Caltech/MSSS
And the low (by modern standards) pixel count needn't be a problem, Ravine says, since the Mastcams will produce stitched images from multiple exposures. 'A mosaic produced from a higher pixel count camera wouldn't offer huge benefits over what we'll be getting.'
Ravine is understandably proud of the work his team has contributed to the project, on the day the rover's mast is raised for the first time: 'We're getting pictures from Mars,' he points out. But it's not hard to detect a note of disappointment in his voice when he mentions the zoom lenses that were being prepared for the project: 'they're currently sitting in a container on the other side of the building.'
Sadly, the cancellation of the zoom lens project for MSL means that it won't produce the 3D footage the team originally hoped for. 'They were going to be 6.5-100mm zoom lenses, which would allow us to set them both to the same focal length for capturing stereo images,' he says. However, problems designing the lens without using wet lubricants (which would require battery-sapping heating to ensure continued operation in Mars' extremely low temperatures), proved difficult and the development was halted.
|The benefits of stitching: a two-image panorama shot with the rover's 1024 x 1024 mono navigation cameras. The Mastcams should produce higher-resolution, color images.
Image Credit: NASA/JPL-Caltech
Hollywood director James Cameron was part of the team and successfully lobbied NASA to re-start the zoom project, with talk of 3D movies showing Curiosity's progress across the Martian landscape. Sadly, although the project was re-started, even Cameron's enthusiasm wasn't enough to ensure they'd be ready in time. 'We're going to get some great mosaics with the focal lengths we've got, but we're not going to get the wide-field cinematic moments or the 3D movies from Mars that Cameron wanted.'
|Another perspective - polar projection of the rover's deck and its surroundings. The image is composed of low-res thumbnails, except the two full res panels used in the image further up the page.
Image Credit: NASA/JPL-Caltech
Jun 25, 2015
Jun 22, 2015
Jul 21, 2015
Apr 28, 2015
|Fascia walkie talkie building London by ian herridge|
from Abstract Architecture
|Global Reach by cjf2|
French President Emmanuel Macron has lodged a legal complaint against a paparazzo who snuck onto the president's private vacation property to take pictures.
Ever wonder what the difference is between compressed, uncompressed and lossless compressed Raw files? Photography Life's Nasim Mansurov breaks it down for you in this informative article.
The oldest known portrait of a US president was just discovered after over a century in storage. It's going up for auction in October, where it's expected to fetch between $150,000 and $250,000.
If you're using the popular Sigma 24-70mm F2.8 Art lens with Sigma's MC-11 converter, listen up: you'll want to update your lens and converter firmware ASAP.
If you've heard it once, you've probably heard it a thousand times: never check in your camera gear when flying. This shattered $11,000 lens is what can happen when you do.
Lensrentals just did its first Cine lens comparison, pitting five top-notch 35mm primes against each other: the Zeiss CP.2 35mm T2.1, Canon CN-E 35mm T1.5, Sigma 35mm T1.5 FF, Rokinon Xeen 35mm T1.5 and Schneider Xenon 35mm T2.1.
A team of Google researchers have found that slightly warping watermarks when embedding them into images can help prevent automatic removal.
You don't have to empty your savings account to take your photography to the next level. These cheap buys cost about $50 or less, and come with outsized benefits for your photography.
Joey L, Dani Diamond, Brandon Woelfel and Jessica Kobeissi go head-to-head in an episode of "4 photographers shoot the same model."
The latest flagship phone from Asus combines a 12MP 1/2.55" Sony IMX362 main sensor with a smaller Sony IMX351 chip for 2x zoom and a background-blurring portrait mode.
The company behind popular photo editor Picktorial 3 just released the X-Pack: a preset package that allows you to add Fuji's in-camera film simulation profiles to your RAF files in post.
Photoshop. GoPro. Every once in a while a product emerges that defines a category. And sometimes, it vanishes just as quickly as it arrived on the scene. This week's Throwback Thursday remembers the Flip, the pocket camcorder everyone had – until they didn't.
The Nokia 8's dual-cam combines the image data from a 13MP RGB sensor and a 13 monochrome chip for better detail, improved dynamic range and lower noise levels.
The company behind retail giant B&H Photo has agreed to pay out $3.2 million in monetary relief and back wages to settle a discrimination and harassment case from 2016.
After a popular Facebook teaser and some studio portrait samples, Godox has finally officially released the Godox A1 smartphone flash and flash trigger. Cheap, versatile and innovative, color us intrigued.
Canon’s EOS 5D Mk IV has won the European Imaging and Sound Association’s Professional DSLR of the Year award, making this the third year in a row that the brand has beaten Nikon to the top spot in the professional camera category.
A photograph and quote tweeted out by former president Barack Obama has officially become the most popular tweet of all time, receiving over 1.3 million retweets and 3.4 million likes.
Edward Weston was one of the most influential photographers of the 20th century, and in this episode of Advancing Your Photography we learn the extreme technique he used to capture one of his most famous still life photos.
Instagram just released a small update that will make a huge difference if you're active on the photo sharing app: threaded comment replies.
Venus Optics has announced the price and delivery date of the second lens to join its Zero-D line up: the 15mm F2 for Sony’s E mount. A lens they've dubbed, "the world's fastest 15mm rectilinear lens for full-frame."
Cinnac is a new social network for photographers that will help you separate your good photos from your great ones through a Tinder-like community-based rating system.
The Canon EF 35mm F2 IS USM is an understated jewel of a lens, and one that we've enjoyed on a variety of cameras since its release almost five years ago. Its relatively small size and image stabilization make it a versatile tool for a variety of photography - check out our sample gallery.
You don't need a fancy studio or tons of gear to capture the kind of classic product photography you see in magazines. In this video, Dustin Dolby shows you how to do it with just a couple of speedlights and some know-how.
The life-logging camera is trying to make a comeback. Say hello to FrontRow, a live-streaming enabled life-logging camera from Ubiquiti that hangs on a necklace like a pendant.
When a prospective client approaches you, don't just say "yes" right away. Here's a useful list of questions you should be asking before you decide to take the job and name your price.
Samsung just revealed a blazing-fast new Solid State Drive capable of data transfer speeds of up to 540MB/s.
DJI has developed a 'Local Data Mode' that lets pilots fly without being connected to the Internet. The mode should calm recent fears over data privacy and security when flying DJI drones.
After 1.7 million downloads on Apple computers since the launch in November 2015, Aurora HDR will be available for Windows PCs for the first time with the 2018 release.
The company behind the new Meyer Optik Goerlitz lens manufacturing business has formed a new brand to bring back the Biotar 75mm F1.5 that was made by Carl Zeiss Jena in the 1940s and 50s.
The updated Qualcomm Spectra system is a dual-camera setup that is capable of sensing depth and motion in real time.