View Full Version : In Praise of the Human Eye...
Tom Lowe
03-24-2007, 11:54 AM
http://farm1.static.flickr.com/187/431977009_22b34133b8.jpg
So I was out shooting some timelapse stuff the other night, and it dawned on me just how amazing the eye is. In order to capture this starry night scene, I had to crank my ISO up to 800 and hold a bulb exposure for 1 minute and five seconds.
Meanwhile, my eyeballs were painting an even more beautiful picture for me, in real time (how many FPS does the eye have?), with infinitely better latitude, clarity, color, resolution. For example, the moon was not blown out by my eyes, but was "perfectly exposed"... I could see every detail of its outline.... even as I was able to see the ground, the stars, the clouds.
All praise the human eye.
PaulClements
03-24-2007, 01:46 PM
Cameras and lenses have a long way to go :)
Graeme Nattress
03-24-2007, 02:27 PM
Actually, it's the brain you should be praising as the eye has many faults, and really doesn't have a static dynamic range that's all that good - but, the brain integrates what the eye sees and makes a mental picture so much better than the eye could see without all that superb processing.
All in all, the human visual system is amazing, but it's also easily fooled.
Graeme
Mike the beginner
03-24-2007, 02:40 PM
Actually, it's the brain you should be praising as the eye has many faults, and really doesn't have a static dynamic range that's all that good - but, the brain integrates what the eye sees and makes a mental picture so much better than the eye could see without all that superb processing.
All in all, the human visual system is amazing, but it's also easily fooled.
Graeme
Could that be a hint at his "Magic Focus":biggrin:
Mike the beginner
Graeme Nattress
03-24-2007, 02:44 PM
Nope, nothing to do with that at all actually.
Graeme
Gopher77
03-24-2007, 04:22 PM
I wonder about the fps we can precieve as well, does our brain take snapshots or is it a continous stream of vision?. I was sitting in the car the other day while my wife was in getting her drivers lisence, I noticed the cars going by on the interstate. As they first came into my site I could see the spokes in thier rims, but when I looked directly at them the motion was blurred, I would just see a solid wheel. I thought maybe the difference in periphal verses main vision. Any way the human perception of vision is amazing.
Graeme Nattress
03-24-2007, 04:28 PM
It does many strange things with fps, so in low light, it's constantly integrating over up to 15 seconds I think. Very clever.
Graeme
Owen James
03-24-2007, 04:37 PM
Hi Guys... From Wiki under EYE:
Dynamic range
The retina has a static contrast ratio of around 100:1 (about 6 1/2 stops). As soon as the eye moves (saccades) it re-adjusts its exposure both chemically and by adjusting the iris... Hence, a dynamic contrast ratio of about 1,000,000:1 (about 20 stops) is possible.
Equivalent Resolution
Roger N. Clark estimates human vision resolution to be equivalent to 576 megapixels (24000 x 24000 pixels) for a 120 degree field of view. Extensive background, assumptions, and calculations are available at http://www.clarkvision.com/imagedetail/eye-resolution.html
Chris Gearhart
03-24-2007, 04:41 PM
There's a human brain in RED?! Cool.
I guess "frankie" takes on new meaning now.
Tom Lowe
03-24-2007, 04:48 PM
I wonder about the fps we can precieve as well, does our brain take snapshots or is it a continous stream of vision?.
The amazing thing to me was that my camera's sensor was taking over one minute to expose a single frame of this night sky scene, but meanwhile, my eyes were exposing seemingly 100fps or more of the same scene, much more crisply, cleanly and beautifully, in 1 second! It would have taken my camera 108 minutes to do what my eyeballs were doing in 1 second!
david farland
03-24-2007, 05:32 PM
Owen,
Nice! I've always thought the eye(s) had the upper hand...sigh!
Trying to emulate the eye's 6.5-static & 20-dynamic stop latitiude in one static frame is a battle
Be interesting if cameras (in future) emulate the characteristics of the eyes when looking over a particular scene and change 'exposure' to fit the focus of the scene. Obviously what draws our focus to a particular part of the scene will be different from person to person. I remember a director explaining to me how left and right 'eyed' people automatically scan a scene differently. Maybe if we could couple the 'in focus' section of a frame to the camera's exposure settings and correctly expose just for that area it would be a 'new' viewing experience. Movies over the last 100 years have taught us a particular way of looking at narrative shoots maybe the future holds some new ways for the viewer.
Cheers,
I was reading a biography of Isaac Newton... when he was younger He was so intrigued by how the eye worked that He stuck a needle into his cornea to see what it did to the light rays entering his eye. The description seemed quite graphic. Talk about dedication to a craft.
damonbots
03-24-2007, 10:52 PM
Well, he did use a darning needle. They're dull, so that's perfectly okay. As if that makes it any less insane. Wow, makes me question my own devotion.
Hey Tom,
You've posted some nice photos recently. I'm taking a trip out to Mohave soon and I'm wondering what kind of set up you have. I think you mentioned Canon? 10-22mm? Do you have an equatorial mount with drive motor?
Tom Lowe
03-24-2007, 11:39 PM
Well, he did use a darning needle. They're dull, so that's perfectly okay. As if that makes it any less insane. Wow, makes me question my own devotion.
Hey Tom,
You've posted some nice photos recently. I'm taking a trip out to Mohave soon and I'm wondering what kind of set up you have. I think you mentioned Canon? 10-22mm? Do you have an equatorial mount with drive motor?
it's just an XT with the 10-22. no telescope motor. i dont think i would want one for timelapse stuff, because the idea is to see star trails, etc. i don't do regular astrophotography (telescopes, shooting galaxies, etc). i use a canon tc80 intervalamoter, which is a great little piece of equipment.
where are you going in the desert?
http://farm1.static.flickr.com/109/311615916_7a2a9471dd.jpg
I'm planning on doing a shot with our moco head that would track the movement of the stars so you can get a long exposure with out the trails. It might look really cool against a mountainous background. Nice picture though Tom. My Brothers and I grew up in the Mojave and its great going out there.. its still amazes me how quiet it is at night and how dark it gets.
Tom Lowe
03-25-2007, 12:11 AM
hmm... wouldn't that blur the mountain, though?
damonbots
03-25-2007, 12:49 AM
hmm... wouldn't that blur the mountain, though?
Depends on how long the exposure is. I've seen some pretty nice tracking shots with perfectly acceptable looking foreground elements.
I'm headed out to Jawbone Canyon about 20 miles outside the city of Mohave. Excellent place to ride motorcycles or just get away from it all. One time I was out there and saw the once in a lifetime kind of meteor. I swear you could see the thing spinning on fire. Of course, I had a couple cold ones in me. I'm sure that magnified the experience. Anyway, hope my pictures turn out like yours!
Tom Lowe
03-25-2007, 12:57 AM
haha, yeah. i always have some cold ones in me when i'm shooting timelapses. what better than setting up a shot, then sitting back with some cold brew while your camera does all the work! :)
The shutter wouldn't be held open. The mountains would look like a like you are doing a normal pan and tilt shot, the stars would be locked off to the movement of the frame.
Tom Lowe
03-25-2007, 01:32 AM
The shutter wouldn't be held open. The mountains would look like a like you are doing a normal pan and tilt shot, the stars would be locked off to the movement of the frame.
Is this for timelapse?
Yeah, sorry I didn't explicitly say that :)
Tom Lowe
03-25-2007, 03:25 AM
So you're doing a panning/tilting timelapse shot tracking the stars? That's interesting. Do you have any video examples of what that looks like?
I'm still planning out my simple moco rig for night stuff. It will be a dolly synced with the shutter, so a stepper motor can pull the camera down a track while shooting. I might ad curved track for "panning" as well.
Exactly.. It should look really cool.. especially if I manage to get some meteors in the shot. I don't have footage yet... its a little busy until after NAB... but I'll definitely post it when we get it.
Jeremy Hughes
03-25-2007, 06:30 AM
As they first came into my site I could see the spokes in thier rims, but when I looked directly at them the motion was blurred, I would just see a solid wheel.
Were you tracking the spokes with your eyes?
Jeremy Hughes
03-25-2007, 06:39 AM
I think the framerate would be nearing 24fps. If you watch a movie in a theatre, you can see hairs on the film, right? Traditional american animation is shot at 12fps and I heard that is the highest possible framerate that you can see as individual pictures which means you would have to see it in at least two frames for it to be classified as still, right?
And when you watch your CRT TV at 60hz you can't see empty fields. So your fps must be below 60. And you can see flickers sometimes so it must be above 30fps. So I think that your frame rate varriable. also, if you look at something from the side of your eye, such as a florecent light, you will see a bit of a flicker. But look at it again straight on and you'll see a solid light. (maybe that's why you saw the spokes like that Gopher77)
I love ocular limpidity.
Finner
03-25-2007, 09:36 AM
Exactly.. It should look really cool.. especially if I manage to get some meteors in the shot. I don't have footage yet... its a little busy until after NAB... but I'll definitely post it when we get it.
Hi Curt,
I'm in the market for a head and had thought before that yours would be very versatile if it not only could be used for motion control but had wheels you could attatch on the back and side and use it just like a gear head. Is this possible? The speed of the pan/tilt wheels would need to be variable but IMO it would become one of the more popular heads out with this feature.
Finner.. Not to hijack the thread but thats something that we definitely have in the works. We are planning on having an accessory that bolts to the under side of Mirus that will have pan and tilt wheels that are fully configurable... so you can have presets that change the virtual gear ratio or adjust dampening etc. We also have a Pan/Tilt bar that allows you to use the head just like a normal tripod head. Its good to get feedback from experienced users such as yourself and knowing that we're spending time on the right things :)
Tom - do you live up in the desert?
Tom Lowe
03-25-2007, 12:33 PM
Exactly.. It should look really cool.. especially if I manage to get some meteors in the shot. I don't have footage yet... its a little busy until after NAB... but I'll definitely post it when we get it.
ha, more likely you will get hundreds of airplanes buzzing your timelapse. :sad:
Word of advice: wait until midnight to start your first shoot. Most planes have cleared the sky by then. The thing is, once you're out there, and once you hit "astronomical sunset" (about an hour and a half after sundown, depending on the terrain) you are really tempted to start shooting. But your first couple of hours will be filled with airplanes crisscrossing the sky, unless you are really out in the middle of nowhere. Joshua Tree, for example, seems to be right near a corridor for LAX or Ontario, or something. I shot one timelapse out there and caught about 100 planes in 3 hours! It looked horrible when I streamed the clip and it ruined what would have otherwise been a beautiful shot.
On the other hand, if you shoot up in Lone Pine, in the Sierras, there are hardly any planes at all, so the one or two that might pass overhead just look like shooting stars on your final timelapse.
I live in Dana Point, in south OC, and I just cruise out to these places in my spare time. You know, I'd love to check out your setup and see what you guys are up to. If you need any help or anything, let me know and I'll come along. I've got a 4-wheel SUV to haul stuff, and I know some choice spots.
tom
btw... don't worry about hijacking.... any talk about timelapse is good with me! sometimes I feel like i'm the only one in the world doing it.
Tom, If you're going to NAB you can check our stuff out at our booth. I have a nice little 4x4 Toyota too, its a necessity for desert travels :) I might hit you up on locations..
Tom Lowe
03-25-2007, 01:15 PM
Tom, If you're going to NAB you can check our stuff out at our booth. I have a nice little 4x4 Toyota too, its a necessity for desert travels :) I might hit you up on locations..
i don't think i will make NAB, but yeah, keep me in mind. i'd be very interested to see what you guys are doing. i might be heading up to Lone Pine this wednesday and thursday, because the moon should be just right. i'll post the timelapse or pics here if it works out.