paulkienitz

paulkienitz

Lives in United States American Canyon, CA, United States
Works as a software developer
Joined on Dec 4, 2006

Comments

Total: 16, showing: 1 – 16
On a photo in the Astronaut Terry Virts: space photography sample gallery (1 comment in total)

omg look at that water!

Link | Posted on Apr 25, 2019 at 22:23 UTC as 1st comment
In reply to:

Peter G: They haven't really said anything new. Super/Ultra capacitors have been fast charging and extremely long lasting for ages.

The capacitor problem is one of energy storage capacity. At BEST they have 10% the capacity of Lithium Batteries by Mass.

So your 20 gram phone battery becomes a 200 gram battery, that weighs more than your phone.

There is continual hype around this idea, mainly to attract investors. But it would be foolish to invest a dime until they can show you a testable prototype that actually has reasonable storage capacity.

I did read the article, and as noted the claim of storing more energy is right there.

But that doesn't mean they can prove it -- this might end up in the same file as the company that claims they're making a thorium powered cell that can power a car.

Link | Posted on Nov 28, 2016 at 20:37 UTC
In reply to:

paulkienitz: 3/3: The second approach is a simple sort of switching power supply, with no transformer. Put a silicon switch and a wide resistor between the main bank and a smaller capacitor, and switch the power to that capacitor on and off to keep it charged to a steady level. This would risk introducing interference to the rest of the circuitry so it would need shielding. And if you don't combine it with the banking idea, it would mean that the supercapacitor might be storing dangerously high voltages.

The safety would be a concern anyway. Someone opening up the device would have to tiptoe very carefully around the capacitor's output leads until he makes sure it's discharged. And in the event of a failure it could release energy a lot more abruptly than a burning lithium battery.

Traditionally, most DC-DC voltage converters used in electronics are simple zener-type regulators which have the same current on input and output. These just convert voltage differences into waste heat. But maybe they're doing better on portable devices now that battery life is such a major engineering goal.

Link | Posted on Nov 28, 2016 at 20:35 UTC
In reply to:

Peter G: They haven't really said anything new. Super/Ultra capacitors have been fast charging and extremely long lasting for ages.

The capacitor problem is one of energy storage capacity. At BEST they have 10% the capacity of Lithium Batteries by Mass.

So your 20 gram phone battery becomes a 200 gram battery, that weighs more than your phone.

There is continual hype around this idea, mainly to attract investors. But it would be foolish to invest a dime until they can show you a testable prototype that actually has reasonable storage capacity.

The claim is that they've beaten that 10% limit. We shall see.

Link | Posted on Nov 23, 2016 at 21:11 UTC

3/3: The second approach is a simple sort of switching power supply, with no transformer. Put a silicon switch and a wide resistor between the main bank and a smaller capacitor, and switch the power to that capacitor on and off to keep it charged to a steady level. This would risk introducing interference to the rest of the circuitry so it would need shielding. And if you don't combine it with the banking idea, it would mean that the supercapacitor might be storing dangerously high voltages.

The safety would be a concern anyway. Someone opening up the device would have to tiptoe very carefully around the capacitor's output leads until he makes sure it's discharged. And in the event of a failure it could release energy a lot more abruptly than a burning lithium battery.

Link | Posted on Nov 23, 2016 at 21:10 UTC as 45th comment | 6 replies

2/3: I can imagine two approaches which would not require a transformer: the first is to divide the capacitor into many banks, and put them all in parallel when the voltage is highest, then in two banks in series when the voltage drops to half, then three banks when it drops to one third, and so on until you decide that it's not worth further subdivisions to squeeze out the remaining fraction of power. That's still inefficient as the voltage regulator still wastes the difference between whatever voltage it's at now and the voltage level at which it switches banks.

Link | Posted on Nov 23, 2016 at 21:10 UTC as 47th comment

1/3: This sounds great, but there's one big catch. Batteries supply power at constant voltage with diminishing current capacity, or to put it another way, increasing resistance. Capacitors, on the other hand, produce voltage proportional to how fully they are charged. An electronic device running off of a supercapacitor will have to be able to handle a wide range of input voltages without wasting half of the power in the way that commonplace voltage regulation does.

Link | Posted on Nov 23, 2016 at 21:09 UTC as 48th comment
On photo Bee eaters' anger in the Anger challenge (9 comments in total)

That posture looks to me more like a child-begging-to-be-fed dance than an anger display. I don't know about bee-eaters but that begging posture is pretty consistent across a wide range of species. A lot of it happens when the parents are trying to make the kids find their own food.

But whatever you call it, it's a gorgeous shot.

Link | Posted on Aug 13, 2015 at 20:21 UTC as 1st comment
On article Hands on with the Pentax 645Z (705 comments in total)
In reply to:

TechManager: This review states that the Pentax 645z uses the same Sony CMOS sensor as the Hasselblad and PhaseOne. This is incorrect as the Hasselblad and PhaseOne are CCD.

I am very skeptical; this camera seems more like a glorified DSLR then a move into a higher quality MF system.

What about tethered shooting? Is this an option with the Pentax?

Though Hassy and Phase One are currently only selling CCDs, I believe both have announced new backs using the Z's Sony sensor.

Leica is also supposedly making an S3. MF if looking lively these days. Maybe enough to tempt Nikon or Sony to jump in, thereby creating a distinct enthusiast or semipro tier in MF.

Link | Posted on Apr 17, 2014 at 22:36 UTC
On article Can computer corrections make simple lenses look good? (159 comments in total)
In reply to:

PowerG9atBlackForest: My English is not very good but I would like to say it like this: It won't work because by laws of nature, chaos (a blurred point is chaos, literally spoken) once it has been created can not be completely reconstituted to it's former organized origin due to the lack of single-valued information.

It's true that the blurring of a bad lens is deterministic, not chaotic. But the photons in the light add noise, which makes it impossible to unravel all the blurring deterministically, because the precision required to fully reconstruct the sharp image would exceed the noise floor.

Link | Posted on Sep 30, 2013 at 21:12 UTC
On article Can computer corrections make simple lenses look good? (159 comments in total)

The corrected version is not as much better than the uncorrected as one might hope.

They might get further by using a doublet as their simple lens -- that way, the initial badness is significantly less.

Link | Posted on Sep 30, 2013 at 21:10 UTC as 58th comment
On article Mobile-friendly forums launched (102 comments in total)

You have my appreciation -- the new layout is much easier to use. Thanks.

Link | Posted on Jan 27, 2013 at 08:46 UTC as 19th comment
In reply to:

David Zamora: What I think will happen in the next couple years is that we will be seeing 3g/4g + wi-fi integrated cameras, but at no cost to the consumer. The camera companies know its silly ask consumers to pay for yet another data plan just for a camera. What I predict will happen is that camera companies will provide 3g/4g for free to the consumer, but the bandwidth will be throttled and the 'free' 3g/4g will most likely have ads on the screen when uploading to the phones 'social apps', eg. Face Book, Twitter, ETC. Similar to how Amazon offers free 3g on their ereaders (with ads).

I think this method will be common place within several years...and will make make way for some great photo sharing on social media sites as well. I'm pretty stoked as to where this is all going!

More workable would be to set up some means of sharing your phone's account with your camera.

Link | Posted on Aug 30, 2012 at 17:44 UTC

Any bets on how long it'll be before samsung sells a "Galaxy" television set?

Link | Posted on Aug 30, 2012 at 17:42 UTC as 26th comment | 1 reply
On article Pentax reveals K lens roadmap for 2012 and 2013 (101 comments in total)

Still no fast 24 or 28mm.

Link | Posted on Feb 4, 2012 at 03:55 UTC as 5th comment | 3 replies

I notice that in the sample given, the place where I click to refocus really doesn't correlate at all well with where the focus ends up getting put.

Link | Posted on Jun 23, 2011 at 19:40 UTC as 34th comment
Total: 16, showing: 1 – 16