The science of imaging

jonnyapplejonnyapple Posts: 130Moderator
edited May 2014 in General Discussions
I read a pretty good article about choosing sensors for scientific imaging and thought some here might be interested based on discussions in days of yore. They have some good rules of thumb that might be useful for photographers even though it's written for microscopists. It's a good idea to push the boundaries on equipment when you can afford to play around so that you know what will limit you before you create a more important image.

Here's the link. I don't know why the bubble shows up saying requested content can't load. It does load the article.
A guide to choosing and using scientific imaging cameras

If you understand what it's saying about how our eyes aren't quantitative (they aren't linear is a better way to say it, IMHO) you'll probably be more merciful to people who shoot jpeg—since a similar kind of compression happens when we see due to the non-linear response of our eye to light, you can make an argument that the most useful data is kept in a well-captured jpeg. This assumes you nail your exposure and white balance and that your in-camera noise processing is better than anything that will ever be invented, so I'm still a staunch advocate for RAW! In fact, the authors argue for non-destructive editing of raw data in the paper.

Their "Think in photons" section is important for those waiting on huge gains in low light performance with new sensors and even revolutionary changes like ditching the bayer pattern to avoid filtering so many photons won't change things too much. An article someone posted on the forum a few years ago gave numbers that showed we really are nearing the physical limits of sensors in terms of dynamic range—there just aren't big enough differences in the number of photons to get a good statistical read on the light level at each pixel. Maybe we could cool our sensors to get rid of some dark current? Even then, the statistical noise from photon counting (shot noise) is going to limit you sometime in low light. I think we're nearly there or maybe there already. In any case, I don't feel like I'll ever need more dynamic range than the D7000 and NEX-6 give me. I'm not saying there will never be reasons to buy new cameras (I've never had problems finding those!), only that before we get caught up in spec envy we should think about what a camera upgrade will actually do for our photography.
CC is welcome. DC is also welcome when I deserve it.
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Comments

  • Parke1953Parke1953 Posts: 456Member
    Wow. when my brain goes back to normal I'll read that again.
  • Benji2505Benji2505 Posts: 520Member
    Interesting article. I have the impression that today's lowlight performers already see more (brightness/color/contrast) than the human eye, so next question is whether things that are technicaly possible still make sense for photography as we discuss it on NRF.
  • FritzFritz Posts: 140Member
    Think as well how far we have come in the past 30 years.
  • MsmotoMsmoto Posts: 5,396Moderator
    Welcome back Jonny….
    Take a look here and you will see a couple of us are "learning' about using our cameras in an unusual way:
    https://www.flickr.com/photos/fantinesfotos/sets/72157644347089402/
    Msmoto, mod
  • SymphoticSymphotic Posts: 703Member
    I remember the first scientific camera I sold and installed in Malaysia. It needed liquid nitrogen to keep its cool. The University where I installed it was out in the hinterlands didn't have liquid nitrogen and they couldn't get it on a regular basis. We had to wait for a dewar to be trucked in from KL. It was a nice location, though. We were really struggling to see photons in the vacuum UV.

    That was a long time ago. Now we have better cameras that have less noise and we only have to cool with a multi-stage TE cooler and a clever refrigeration unit. And now they have plenty of liquid nitrogen produced in Malaysia.

    "Symphotic" (the company, not me) got its start making scientific cameras based on Charge Injection Devices, but we have branched out into other methods of imaging.
    Jack Roberts
    "Discovery consists in seeing what everyone else has seen and thinking what nobody else has thought"--Albert Szent-Gyorgy
  • jonnyapplejonnyapple Posts: 130Moderator
    Very nice, Tommy. We had Tom Davis come talk to us this year, who has had a few of his images on NASA's astronomy picture of the day. It was very enlightening and showed me just how little I know about astrophotography. I would love to use his camera, though—something like a 3" CCD with no bayer filter (he has a filter wheel to get color from multiple exposures) and a cooling system.

    Cool story, @symphotic.
    CC is welcome. DC is also welcome when I deserve it.
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