ProfHankD

ProfHankD

Lives in United States Lexington, United States
Works as a Professor
Has a website at http://aggregate.org/hankd/
Joined on Mar 27, 2008
About me:

Plan: to change the way people think about and use cameras by taking advantage of cameras as computing systems; engineering camera systems to provide new abilities and improved quality.

Comments

Total: 1396, showing: 21 – 40
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There are two generic problems with IOT (Internet Of Things) devices:

1. They know a lot about us (arguably LOTS more for drones with video, audio, and GPS) and are often in "trusted" environments, for example, with access to networks behind firewalls

2. They can (and most do) "phone home" (typically to the manufacturer) providing data and potentially unsecured access to things we didn't think they could touch

DJI is far from alone in having drones logging and phoning home with data (most IOTs do), but they do NOT make any of their software infrastructure available for users to examine... so nobody really knows exactly what they do. This is where open source software is much less scary -- you can actually know what the device is capable of doing. Especially for sales to US military, I think it would be completely reasonable to require that all software be either audited by a 3rd party or provided as source, and it should also be possible to completely disable "phoning home."

Link | Posted on Aug 5, 2017 at 00:17 UTC as 26th comment | 2 replies
On article Nine new lens adapters announced for the Fujifilm GFX (90 comments in total)
In reply to:

tkbslc: Given that 24x36mm film has a 43.3mm imaging circle, you could get considerable extra real estate with different aspect ratios and still staying inside the native imaging circle.

2:1 crop would be 19.3x38.7mm sensor area (vs 18x36mm crop)
16:9 crop = 21.2x37.7mm sensor area (vs 20.2 x 36mm FF crop)
4:5 crop = 27x33.8mm (vs 24x30mm FF crop)
3:4 crop = 26x34.5mm (vs 24x31.9mm crop)
1:1 crop = 30.6x30.6 (vs 24x24 FF crop)
(numbers rounded)

And given that you'd likely be able to oversize crop at least a little on most lenses, you'll probably go a bit farther. If you planned to shoot everything at 2:3, then you'd be gaining little if anything on the larger sensor. but anything else, you'll have a lot more data to work with.

If you like to shoot 1:1, then a ff lens at 30.5x30.5 is only a 1.08x crop factor from the native GFX cropped to 1:1. And I'm betting the vast majority of lenses could tolerate 8% overcrop farily well, leaving that at full GFX sensor height.

Yes, this was always the suspected reason for Sony's odd-sized sensor: it should be a great multi-aspect back for 135-format SLR lenses. It'll be interesting to see if any current production 3rd party lens makers decide to repackage their lenses directly to this mount....

Link | Posted on Aug 3, 2017 at 23:36 UTC
In reply to:

falconeyes: This is an application of "structure from motion" (google for it). The execution is rather well done, most applications lack the quality in results a photographer would need. Kudos to the researchers.

Yeah, pretty much. It's basically creating a 3D (well, maybe 2.5D) model from a sequence of "zoom by walking" shots and then re-rendering the 3D model using potentially different perspectives for different depth regions. Like you, I'm pleasantly surprised by the apparent resulting image quality. However, the really new part is that different perspectives for different depths idea, and I'm not so sure that's a good thing....

Link | Posted on Aug 3, 2017 at 13:42 UTC
In reply to:

Zdman: Not an apple fan and refuse to use their products for myself but what he says is not without merit. If you've ever tried using the Android API you'll quickly discover what a mess it is. There is unexplained behavior all over the place and hardware compatibility is a nightmare. Almost every 3rd party app has people complaining it won't work on their device. Want to access a new feature, forget about it, you'll have to wait till the next API update and then you'll only be able to use it on devices that run the next version of Android (and very few devices update, usually only flagships). I really wish Microsoft had been more sucessful in the phone space as they know how to maintain an operating system.

Zdman: I wonder who really has been buying all those DSLRs. My wife has never gone with a camera that didn't fit in her purse, nor did my mom. The women (and men) I've seen with DSLRs are usually folks who consider themselves to be "amateur photography buffs" although they might not have a clue what an f/stop actually is. There's also the bit of fun that recording school concerts is no longer allowed in many places because there may be children on stage with your kid who are, for example, kids removed from a abusive parent (I used to be a foster parent so I know it is illegal to post photos of a foster kid; it's considered a threat to their safety). Anyway, I'm just happy that now you see people using phones rather than ipads. ;-)

Link | Posted on Aug 3, 2017 at 11:04 UTC

Nice images, but the stitching can be a nightmare when component images are temporally skewed -- for example, ripples on the surface of water don't line up. I have a rig that can shoot 288MP simultaneously, and there are various camera array systems that can capture 1GP or more simultaneously; they're a pain too, but at least they don't give motion artifacts....

PS: Real supercomputing folks don't brag about overclocking; in fact, we are more likely to underclock to increase reliability of the massively-parallel system.

Link | Posted on Aug 2, 2017 at 14:31 UTC as 9th comment
In reply to:

Zdman: Not an apple fan and refuse to use their products for myself but what he says is not without merit. If you've ever tried using the Android API you'll quickly discover what a mess it is. There is unexplained behavior all over the place and hardware compatibility is a nightmare. Almost every 3rd party app has people complaining it won't work on their device. Want to access a new feature, forget about it, you'll have to wait till the next API update and then you'll only be able to use it on devices that run the next version of Android (and very few devices update, usually only flagships). I really wish Microsoft had been more sucessful in the phone space as they know how to maintain an operating system.

Apple has always had the advantage of controlling everything... which is why I always thought their 1984 commercial was a little odd. Anyway, Android does suffer from having relatively open standardization, and I'm sure the result is that rolling-out a new technology to the entire Android infrastructure can be a little slower. The same can be said about Linux, from which Android is derived... although the openness does mean more people can and do contribute new technology, and most software developers prefer Linux to proprietary OS platforms (I sure do).

The thing that is dumb here is talking about iPhone ending DSLRs -- which is sort of like saying the iPod killed reel-to-reel tape audio recording, which it didn't. The thing that is replacing DSLRs is mirrorless; smartphones are really in an entirely different usage space and computational photography doesn't change any of the physics that favor larger-than-fit-in-a-phone sensors for various photographic applications.

Link | Posted on Aug 1, 2017 at 11:13 UTC
On article Fujifilm GF 110mm F2 sample gallery (153 comments in total)
In reply to:

ProfHankD: Pretty awesome stuff. It's probably better than my A7RII + Samyang 85mm f/1.4, but I think my A7RII + Sony 100mm STF still beats it. Just imagine next generation when GFX gets the same sensor tech used in the A7RII....

For me, that's sort of like imaging Ansel Adams taking his film to a 24-hour development kiosk in a local shopping center. An artist should know their medium. Then again, I used to do freelance commercial photography and now I do computational photography research, so I'm biased and YMMV....

Link | Posted on Jul 26, 2017 at 17:35 UTC
On article Fujifilm GF 110mm F2 sample gallery (153 comments in total)

Pretty awesome stuff. It's probably better than my A7RII + Samyang 85mm f/1.4, but I think my A7RII + Sony 100mm STF still beats it. Just imagine next generation when GFX gets the same sensor tech used in the A7RII....

Link | Posted on Jul 26, 2017 at 15:05 UTC as 32nd comment | 5 replies
In reply to:

Robbeedee: 4 dimensional. So x-y-z and...? It is stupid calling stereo photography as 4D, since it is already a stretch calling a depth map 3D.

Again, this does NOT do anything treating TIME as a dimension; in fact, it does slow serial sampling within a capture as an arm repositions the sensor. Forgive my repeating this, but my TDCI (Time Domain Continuous Imaging) is treating time as full dimension and pretty much nothing else is.

Link | Posted on Jul 26, 2017 at 14:52 UTC
In reply to:

Sea Hunt 2: I understand what 3D means but 4D? Sounds like a camera by Alberto Einstein.

Tom, plenoptic arrays (see Lytro) record the pixel value for each of multiple angles of entry -- this apparently distinguishes 15x15 different ray angles per "pixel" location (of which there are 1600x200).

PS: My TDCI (Time Domain Continuous Imaging) work is really the thing treating time as a full (continuous) dimension.

Link | Posted on Jul 26, 2017 at 13:38 UTC
In reply to:

Robbeedee: 4 dimensional. So x-y-z and...? It is stupid calling stereo photography as 4D, since it is already a stretch calling a depth map 3D.

A depth map is technically 2.5D. I believe this is a 2D plenoptic sample pattern replicated over 2D image plane coordinates.

Link | Posted on Jul 26, 2017 at 13:21 UTC
In reply to:

Sea Hunt 2: I understand what 3D means but 4D? Sounds like a camera by Alberto Einstein.

The technical paper, http://www.computationalimaging.org/wp-content/uploads/2017/04/LFMonocentric.pdf , doesn't actually say what the 4 dimensions they count are, but NOT TIME: they quote resolution as 15x15x1600x200, which is apparently the light field array size times the "conventional" spatial resolution for a complete traversal of the sensor across the 138-degree field of view. I'm a little confused that it produces color images -- probably standard Bayer pattern on the sensor, but they never explain that.

The contribution of the paper is basically that a monocentric (sphere or ball) lens can have a large enough aperture to support light field imaging with a very wide field of view, with the complication that you have a spherical focal plane. Not surprising, but I haven't seen it done before.

Link | Posted on Jul 26, 2017 at 13:14 UTC

Yet another spherical (full sphere) lens, tiled-sensor, curved focal plane thing... this time, adding light field microlenses and moving one sensor rather than making an array camera (although they talk about it as a prototype for an array camera). Pretty scary optical relay system that goes behind that little sphere....

A logical thing to try given the DARPA preference for funding this type of tiled spherical camera. Not a particularly impressive prototype, but it does show the idea works (which of course it had to).

Link | Posted on Jul 26, 2017 at 12:45 UTC as 3rd comment

The music video is odd, but I suppose it was fun for their employees? "Passage of light" sounds and, especially in the opening sequence, looks more like they have died and are walking into the light. The F mount video is pretty impressive but also disturbingly stops now rather than ending with a little something saying it will continue. Overall, kind of depressing when I expected more of a "here's to the next hundred years" type of theme. Look forward, Nikon, you can have a future....

Link | Posted on Jul 26, 2017 at 12:05 UTC as 21st comment
On article Nikon announces development of D850 (538 comments in total)

And now a camera with the amazing ability to do intervalometer shots!

Really? This is the bragging point? At least 8K is 7680×4320, so that should mean the sensor has at least 7680 pixels in the horizontal... which would mean 7680x5120 minimum 3:2 resolution, or about 39MP: so the Sony 42MP sensor seems likely.

Link | Posted on Jul 26, 2017 at 11:40 UTC as 26th comment | 2 replies
On article Opinion: DJI has abandoned professionals (416 comments in total)

Two things:

1. DJI has a corporate culture and history of tightly controlling what users can do with their products. Many companies do, and this is problematic for professional users (and researchers like me). I'm talking mostly about things like not providing an API for use of the onboard sensors, etc., in user-written control software... but there also are privacy concerns when a product "calls home."

2. There are signs of an intense battle coming over how UAVs should be allowed to operate. The US government took a shot at establishing a minimal registration program, but now it's clear we need some controls and unclear how they can be established. I suspect DJI put these flight restrictions in largely as a preventative measure against what they would view as more harmful legislation being passed in the future.

Basically, I think this is completely consistent with DJI's history and might help discourage implementation of nastier regulations or at least get DJI products exempted.

Link | Posted on Jul 23, 2017 at 17:09 UTC as 99th comment | 3 replies
On article Photo of the week: Torment (74 comments in total)
In reply to:

Dheorl: Am I the only one who prefers it cropped to lose the bottom 1/8th or so?

Actually, I think you can make it a stronger (much more abstract) image by just taking the bottom 2/3. The mountains are kind of "predictable." I think I would have tried a horizontal shot getting the "trees" and a little bit of the water pattern as "sky." Come to think of it, having the very bottom a bit out of focus might also have helped... I think I would have tried that too.

Link | Posted on Jul 22, 2017 at 20:29 UTC

"This system has been used only in fresh water...never salt." Hmm. The photo shown above doesn't look like fresh water to me, but maybe brackish...? There are kind-of strange vertical marks on the example shot too. Anyway, I wouldn't try this: water seals must be really dry when the camera is closed, and opening the back to change to a new sheet of film would tend to get the seals moist enough that I'd be worried about leaking if a new sheet was inserted to take another shot before the seals completely dried.... Besides, this is DPReview, right? This isn't D. ;-)

Link | Posted on Jul 22, 2017 at 00:24 UTC as 5th comment
In reply to:

paul_kew: 8/10, got 4 & 6 wrong. Unfortunately I can't remember which photos they were, I wish they had a more detailed answer page.

I got 7/10, but that was mostly guessing what they wanted me to see. I think they wanted us to see things. However, I honestly feel EVERY photo has been heavily manipulated -- they sure don't look like good quality OOC JPEGs, but softer and artifacted as though they've been JPEG recompressed multiple times, and I found that more distracting than the intended "where's Waldo?" game.

Link | Posted on Jul 21, 2017 at 00:11 UTC
In reply to:

rolleiflex: Similar mistake canon made with lack of c-log on the early batches 5dmk4, which eventually needed a hardware fix. Now canon think they can sugarcoat their turd with a flippy screen and dualpixel AF. It does not work on me.

Im living in a fantasy land where I hope canon are embarrassed enough with headlines on key websites regarding the abysmal DR in this 6D2 sensor, that somehow they can offer a fix to give DR that is at least parity with the 80D. Im not even asking for better, just parity please.

There are at least a couple of tricks possible to improve DR in software. If you can get a dual-pixel raw, there can be about 1 stop extra DR available (not quite, because Canon's raw adds the two sides rather than averaging them -- so it clips). There's also a chance the Magic Lantern folks could do better in camera, not just using dual pixels, but also using the dual ISO hack they created for earlier Canons... but porting ML takes time and that's a development project without the support it so richly deserves.

Link | Posted on Jul 20, 2017 at 12:10 UTC
Total: 1396, showing: 21 – 40
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