Please create an account to participate in the Slashdot moderation system

 



Forgot your password?
typodupeerror
×

Comment Re:Is it "too real"? (Score 1) 607

I think the one key thing that you do not expect is how aperture effects DOF and exposure. So you need a certain amount of light to enter the back of the camera. I think the way you think is very technical, think about it like you need enough to beat the S/N for a decent photo. Can you buy that? Well when you have the shutter open for a short period of time you are letting less light in. So to compensate you can use more light. Well that's hard because you already are bathing the set with a lot of light. But let's assume you could get more light. There is also the issue of darker materials reflect less light than lighter ones and you need to make sure that the white and other such light colored objects in the scene do not wash-out completely while you have still detail in the darker areas. In fact with a lot of light you can actually see the lens elements themselves in the image you capture. So it's hard, you need just the right levels. Images that are overexposed look dull and lifeless as well as washed-out. The more overexposed that they are, the harder to correct, and if over-saturated in areas, they really cannot be fixed later. Photographers call this a blown highlight. Again in your way of thinking, all those values are pegged at 16K or whatever even though there was a whole range of them beyond. Incidentally CCD response also happens to not be linear. But there are more fundamental problems.

See the another way you could let more light into the back of the camera would be to use a larger aperture. This means that the shutter opens to a larger diameter. So first the problem is one that you can throw money at to solve to a certain extent at least. For practical reasons lens that have a larger aperture have other deficiencies. One very common one is that they have a much more limited zoom. To some extent better made lens can solve that, but there are some limits. Like you want a big CCD back there right, so you can average to beat some of the noise. Oh and you say you want 3CCD (which further reduces light to each CCD BTW). Ad yes you do want to be able to pull the shot (zoom), so soon you could make an awesome camera, but it would rival the Hubble in terms of size. (I exaggerate a bit, but you get the idea.) Still it's hard, they tend to be less quality lens for the same price as well, like 5 elements instead of 7, more aberration, etc. But beyond those practical aspects, there is the most fundamental problem, and that is depth of field. When you have a small aperture, it's like a pin-hole camera. Things close by and those things relatively nearby will seem in focus. But use a wide aperture and only those things relatively close to the focal point of your lens will be in focus. It's actually sort of neat in say single subject portrait photography since anything makes an interesting sort of random looking background and you only need to focus on a single face, but it's not good for most films where you have many subjects you want in focus as well as having the background maybe out of focus but with enough detail to still make out more or less what is there instead of plasma looking globs of color. That's an optics things, really can't be solved computationally or anything like that. Would need radical new lens technology, one that splits light most likely, getting you back to your original problem. Yes there are high speed videos, lots of them, but next time you watch them pay attention if you can see anything other than the popping balloon or what not in focus and how saturated the or overblown just generally balanced well the images look. Usually it's some scientific context and you can make-out what process is occurring, but it does not look good in terms of cinematography, like the shadows look dead or really noisy.

Comment Re:Tried it. (Score 1) 378

I tried once too, but before that I called the officer that had given me the ticket to let him know I was going to. After I spoke a bit he said that he was driving on a completely different road when he caught me speeding than he actually was, one near the subdivision I pulled-off into where traffic was calm and we would not block a lane. The reality was that he was pulling out of the road that the police station is next to, I saw him the entire time. I told him that he was not, he said, "Who is the judge going to believe?" My math all hinged on his radar detector being wrong on account of his turning not stationary or coming behind or oncoming when I went by. So I just paid.

Comment Re:Not only ineffective, but not proven safe (Score 1) 494

Maybe you could answer the question I posed here: http://slashdot.org/comments.pl?sid=2711231&cid=39276341

Basically I am wondering about the change in angle of the x-rays that are not captured when others are waiting in line. Has the wavelength change made them non-ionizing? Are the angles such that they do not hit the people waiting in line at security? I have not seen this discussed anywhere, I wonder if there is some simple explanation to why it's not a concern.

Comment Re:Not only ineffective, but not proven safe (Score 1) 494

Maybe someone can answer this for me. The back scatter machines work based on compton scattering. I know little about physics, but what I intuitively understand is that the photon comes along, knocks an electron away, and a photon goes off at a different angle. The whole electron knocking off bugs me since that means it's ionizing radiation. Also the wavelength changes of that back scattered x-ray, gets longer the bigger the angle of deflection. So there I was in the airport the first time after these things got introduced and knowing that little bit I did. I'm waiting in line and hundreds of the scans happened right in front of me from a handful of machines. Maybe I was at the front row nearest to the machine when forty scans happened from them. So wouldn't the back scattered x-rays hit me? Would it be very little? Would the ones that did be at a sufficient deflection angle that it was no longer ioniozing? (That bit I doubt, in the line I was with the machines all about there were all sorts of angles from many.) Anyone know any info about that where my concern about exposure waiting in line is addressed? Everything I have read addresses it from the point of view that while you are being scanned once you get little exposure only.

Comment Re:Zoom and enhance! (Score 1) 125

Not really as bad as you think. All it does is show frame n in one eye and frame n + 1 in the other, stretched (and cropped to preserve aspect ratio) a bit to exaggerate the depth. So things that do not move, they are assumed to be in the background, moving things seem to be closer. It's not as bad as you say, no resetting one key frames for example, but yes the effect is strange, often not right, as well as neat.

Comment Re:The feds' approach to fuel efficiency is all wr (Score 1) 891

There are many reasons that the CAFE regulations are suboptimal but yours is not one of them. CAFE calculates the harmonic mean, ie the inverse, so it effectively is calculating the mean if every car was driven the same distance, not used the same amount of fuel, so just like thinking in the European manner unlike our MPG. Real reasons that CAFE is suboptimal is that there is still a domestic and other average (for cars), the car vs truck limits, the fleet penalty is very low, the arbitrary E85 benefit, the new 'footprint' requirements that will be the new loophole to allowing manufactures continue selling large fuel efficient but very profitable vehicles, and so on (there is more).

Comment Re:At this stage, why have a hash function at all? (Score 1) 156

It would work, one script would then check to see if the keys were one of year, month, or day. Another script would verify that it only got zip, city, or state. Those keys that it cared about, it could put those values into a hash table if it wanted, or not if it just used them right then and there. The problem is that framework like plone or rack or tomcat or whatever it is that calls your script doesn't know what are the variables that you will need. It puts them all in a hash. Oh sure that use an array to pass them all is linear, but the current attack is quadratic. First you add the first, you get an empty bucket list. Now you add the second, have to look at the first one... Now you add n, first look through the previous n - 1. See?

Comment Re:They didn't infect Kippo (Score 2) 227

Kippo will not work for anyone but the kiddies. Did you change the default root passwords even? Those two are a real tip-off to a honeypot. Also there are hardly any commands, ifconfig never changes, and in this case /etc/issue says Debian and these people were after CentOS. If you had been hacked, you would have had the vulnerable sshd and no Kippo logs would have been the least of your worries.

Comment Re:Open Source an MMO? (Score 1) 121

Sorry it was "Prince of Persia: The Sands of Time." After my sons got the set with ostriches they pleaded with me to watch the film. The movie and video game released at the same time were not age appropriate for them and that set made them want to watch the film very badly which I guess was the point for the deal.

Slashdot Top Deals

And it should be the law: If you use the word `paradigm' without knowing what the dictionary says it means, you go to jail. No exceptions. -- David Jones

Working...