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: 1306, showing: 21 – 40
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On article Shiftcam for iPhone 7 Plus review (58 comments in total)

Yet one more reason for people using cell phone cameras to laugh at us folks with a dedicated camera and a bag full of lenses.... Of course, we get the last laugh when one looks at the image quality. :-)

Link | Posted on Jun 7, 2017 at 12:00 UTC as 35th comment | 1 reply

To your questions....

1) It's not just a lack of standards for content and presentation; people don't really have a stable notion of what VR is. Is it head-mounted displays? Is it stereo images or true 3D model rendering where you can look behind things? Is it a 360 view? What about audio directionality? How interactive must it be? Is AR (augmented reality) VR?

2) Of course everybody will use it, and without much thought about it. Heck, one of the options on Toyotas now is to have a virtual overhead view of the car so you can see everything around you for parking, etc. -- that's definitely VR to me because it has to build and render the 3D scene content model.

Link | Posted on Jun 6, 2017 at 13:56 UTC as 58th comment
On article Fujifilm GF 32-64mm F4 R LM WR sample gallery (140 comments in total)
In reply to:

ProfHankD: I hate Provia. To me, these all look way too contrasty -- with shadows all blocked-up and whites just slightly blown-out. I will admit that Fuji does a great job of matching the look of their films, but I never liked their films very much and that Sony sensor is capable of so much better!

The lens seems to do well enough to be very versatile with nice bokeh for a zoom. Flare is bad in a couple of shots... until I notice they're at f/32 and f/22. Those are not apertures I'd ever use (other than to check for dust on the sensor ;-) ).

Lan: Yeah, I figured as much. I'm not fond of sunstars either (that's still flare to me), but it looks like you can get those by f/16 quite easily. So, J. J. Abrams fans can be happy without going too far past the diffraction limit nor turning every little speck of sensor dust into a black hole.... ;-)

Link | Posted on May 29, 2017 at 15:55 UTC
On article Fujifilm GF 32-64mm F4 R LM WR sample gallery (140 comments in total)

I hate Provia. To me, these all look way too contrasty -- with shadows all blocked-up and whites just slightly blown-out. I will admit that Fuji does a great job of matching the look of their films, but I never liked their films very much and that Sony sensor is capable of so much better!

The lens seems to do well enough to be very versatile with nice bokeh for a zoom. Flare is bad in a couple of shots... until I notice they're at f/32 and f/22. Those are not apertures I'd ever use (other than to check for dust on the sensor ;-) ).

Link | Posted on May 29, 2017 at 14:19 UTC as 36th comment | 5 replies
On article How do you know you need a new camera? (409 comments in total)

As a computer engineer known for his work in supercomputing, people are often shocked to see me using a 5+ year old desktop and 3+ primary laptop -- but it's very disruptive to be changing my primary working environment for developing code, writing papers, and administering the courses I teach. Yeah, for my research I'll often have fleets of new and even pre-release stuff for both parallel computing and computational photography, but upgrades of my "production" kit are much rarer and generally wait until there is a qualitative (not just quantitative) reason to upgrade.

My "production" digital camera sequence: Casio QV100 (QV120 when QV100 got dunked) -> Kodak DC210 -> Kodak DC260 -> Canon G1 -> Canon G5 -> Sony F828 -> Sony A100 -> Sony A350 -> Sony NEX-5 -> Sony NEX-7 -> Sony A7II. I might soon be switching to my A7RII, but the jump from A7II to A7RII is mostly quantitative. So, 11 cameras in twenty years... the last 6 of which I've still found a use for in the past year.

Link | Posted on May 27, 2017 at 11:47 UTC as 155th comment
In reply to:

Jefftan: interesting time. something big is coming to camera world next year in 2018

as rumor suggest, next year all Canon/Nikon/Sony will have their full frame mirrorless ready to battle it out

last 5 years is boring. Next 5 years is not. It will determine the future direction of camera and the whole industry

When the dust settle. What will happen to APS-C / 2nd tier camera company is anyone guess

Canon is incremental. They'll come out with a FF mirrorless when they can see how to build it with parts already in stock. The on-sensor dual-pixel PDAF is a big step in that direction, making viable AF possible... but at 5D IV prices, it isn't cheap. Nikon, well, they could basically sell a rebranded Sony... but then they'd be going head-to-head with the company that supplies the key tech; Nikon has done much better sticking to camera formats Sony doesn't compete in.

Link | Posted on May 27, 2017 at 06:03 UTC
In reply to:

mxx: Nice touch, Damien, about the shopping basket!

I'd bet that was an attempt to see how many there were... although I don't care.

I have a couple of f/1.2 (Canon FL 55mm and Minolta Rokkor 58mm), focal reducers for APS-C (add some speed when not using FF), and I have several f/1 or faster special purpose lenses (fastest f/0.75) -- the total cost of which wouldn't pay the sales tax on one of these Noctilux.

Link | Posted on May 26, 2017 at 13:49 UTC
On article 2017 Roundup: Consumer Long Zoom Compacts (166 comments in total)

I have to say that the superzooms have gotten really fantastic in flexibility at low cost. I recently purchased a fleet of factory-refurb SX530HS for $130 each (for reprogramming using CHDK), and they are shockingly capable cameras with most aspects very well thought out -- e.g., having a single button to temporarily zoom out showing you a zoom crop window, so you can easily find your distant target that went out of frame, and releasing the button zooms you back in. Lack of an EVF really hurts, although I'm waiting for a $4 LCD magnifier viewfinder attachment.... Point is, as long as you're in good lighting, 50X zoom starts way under $200.

Incidentally, CHDK raws reveal the SX530HS has more bad pixels than I've seen on any other sensor and the 24-1200 is really more like a distorted-at-the-wide-end 18-1200 (usably about 20-1200 when corrected from raw), but the OOC JPEGs look quite good.

Link | Posted on May 26, 2017 at 12:26 UTC as 25th comment

Should be perfectly viable. I published a year ago on using 1.4-1.5X teleconverters to convert APS-C optics to full frame -- that actually was worth doing. Here are slides from my Electronic Imaging 2016 paper: http://aggregate.org/DIT/EI2016/ei2016MIX.pdf

Link | Posted on May 26, 2017 at 04:24 UTC as 6th comment
On article Analog gems: 10 excellent, affordable film cameras (805 comments in total)
In reply to:

Khun_K: it is a short list of something that the article title should really avoid using "gems" ??? overly subjective list at best

It's trolling... trying to incite lots of comments with random opinions and zero digital photography content. And I just commented -- so it worked! ;-)

BTW, many photography classes still require students to use a film camera, so there are many lists of "recommended" film cameras out there....

Link | Posted on May 20, 2017 at 11:09 UTC
In reply to:

Irfan M: i had the Canon 5D Mark 4 to myself within a few days of its release in my state . I had to face the issue of the cam going dead within a few days of my first purchase after which i had contacted the canon company and got my device replaced , now this is the third time it is happening after a few months span while it had gone dead a second time after a month of its first replacement which is quite disappointing considering the works that i have committed to . I am sending this with a huge regret now as i was a canon member for the last 5 years and more along with many of our other professionals and if this is the state of service that we are getting then i am really sorry to tell you that we will be forced to change to other companies for their products due to this reason.

I use a LOT of different cameras -- largely for computational photography research.

I use more Canon PowerShots that I reprogram using CHDK than any other cameras; just got a fleet of twenty-four sx530hs. However, I generally prefer the Sony RX100 IV/V and various mirrorless bodies for "serious" stuff (mostly shooting with an A7II and A7RII now). I have had some fun with dozens of network cameras and USB cameras, an EOS M under ML, and even have a Lytro Illum.

I got the 5D IV for the dual-pixel raws, which should have allowed me to do some great things, but have honestly been a big disappointment due to a few bad choices made by Canon. I have also been surprised to see the 5D IV AF outperformed by my A7RII + metabones adapter using the same lenses. That said, overall the 5D IV seems a very competent and well-polished DSLR, and it's the first Canon DSLR to compete favorably with IQ from things like my Sony NEX-7.

Link | Posted on May 20, 2017 at 00:49 UTC
In reply to:

ProfHankD: Again, the D750 wins basically because you say it's cheaper than the much better A7RII... when in fact the A7II would be it's competitor, and the A7II is cheaper than the D750. I think these comparison grouping are getting less and less meaningful. BTW, my A7RII was cheaper than my 5D IV, and I don't think the 5D IV is very competitive in most aspects... so how come "The other great do-it-all camera in this class is Canon's EOS 5D Mark IV" and the A7RII is listed as "Money no object"?

Let me repeat my plea: group cameras BY APPROPRIATENESS FOR A PARTICULAR TYPE OF PHOTOGRAPHY. Saying "best" without specifying for what is pointless.

HowaboutRAW: again, my point is saying best without saying for what is meaningless.

As for astounding AF, well, I haven't tried a D750 because it can't use most of my lenses... and even my A7II can AF pretty much ALL of them -- including the purely manual ones, thanks to the TechArt Pro LM-EA7, which I think is much more "astounding AF" than being a tad faster with a few lenses. ;-) Then again, I honestly rarely favor using AF anyway....

Link | Posted on May 19, 2017 at 23:32 UTC
In reply to:

Irfan M: i had the Canon 5D Mark 4 to myself within a few days of its release in my state . I had to face the issue of the cam going dead within a few days of my first purchase after which i had contacted the canon company and got my device replaced , now this is the third time it is happening after a few months span while it had gone dead a second time after a month of its first replacement which is quite disappointing considering the works that i have committed to . I am sending this with a huge regret now as i was a canon member for the last 5 years and more along with many of our other professionals and if this is the state of service that we are getting then i am really sorry to tell you that we will be forced to change to other companies for their products due to this reason.

I haven't had my 5D IV stay dead, but I have repeatedly had it freeze for no apparent reason. I've also noted it behaving really strangely if you power up with a nearly dead battery. What exactly was the failure mode you saw?

Link | Posted on May 19, 2017 at 23:18 UTC

Again, the D750 wins basically because you say it's cheaper than the much better A7RII... when in fact the A7II would be it's competitor, and the A7II is cheaper than the D750. I think these comparison grouping are getting less and less meaningful. BTW, my A7RII was cheaper than my 5D IV, and I don't think the 5D IV is very competitive in most aspects... so how come "The other great do-it-all camera in this class is Canon's EOS 5D Mark IV" and the A7RII is listed as "Money no object"?

Let me repeat my plea: group cameras BY APPROPRIATENESS FOR A PARTICULAR TYPE OF PHOTOGRAPHY. Saying "best" without specifying for what is pointless.

Link | Posted on May 19, 2017 at 23:14 UTC as 96th comment | 4 replies
On article Sony a9: more speed, less dynamic range (666 comments in total)
In reply to:

TheEulerID: By "In a perfect world, Sony would have offered a 12-bit Raw mode with a lossless compression curve (without that second stage of localized compression that leads to edge artifacts) for smaller file sizes with minimal loss in quality."

Do you actually mean a gamma compression on a curve? If so, I'd agree but it has to be pointed out that gamma compression is not lossless in the sense that it's used in the compression of data files. Gamma compression makes used of the fact that the lower bits of the brighter areas of the image are just capturing shot noise and thus can be discarded. You only need the lower bits for the darker areas of an image where it has some relevance.

A properly defined gamma compression system would be perfect for RAW data and would not exhibit artefacts or lose any real data, but I fear the "lossless" fundamentalists will still have a fit about it, even if there is no loss in image quality.

The ARW compression scheme is actually pretty clever. It obtains CONSTANT compression (to 8 bits/pixel), which means raw pixel data can be randomly accessed and even modified while in compressed form, and the algorithm is simple to implement in hardware. I don't yet know if Sony does this in specific cameras, but it would be perfectly feasible to structure the raw sensor data as compressed in this way in order to improve the internal transfer speeds and effectively increase memory space. The artifacts it introduces are rarely significant (certainly less than other constant compression schemes with comparable compression ratios) and can be credibly repaired by KARWY, http://aggregate.org/DIT/EI2016/ei2016ARW.pdf .

The ARW compression was originally designed for 12 bit data. The real issue is that as cameras go to 14 bits and beyond, the compression ratio gets too high, and then you can see some artifacting -- but the A9 is strictly 12 bit.

Link | Posted on May 19, 2017 at 10:33 UTC
On article Sony a9: more speed, less dynamic range (666 comments in total)
In reply to:

ProfHankD: "In other words, it appears this sensor was likely optimized for speed at the expense of low ISO dynamic range." -- shouldn't it be? And there's no problem at higher ISOs, maybe even a little improvement. This sounds like exactly what the A9 should do.

In fact, this is just following Minolta's path. The Maxxum 9 was in many ways an inferior camera to the Maxxum 7, but the 9 was faster and more rugged.

To me, the real question is: will there be an A9S and A9R?

Rishi: Perhaps I misunderstood what you said above -- what did you mean when you said "normalized" for the SNR? Was that with both images scaled to the same size, or was that per captured pixel? The A9 would need to be better per pixel to have parity when scaled to the same size.

Link | Posted on May 19, 2017 at 10:13 UTC
On article Sony a9: more speed, less dynamic range (666 comments in total)
In reply to:

ProfHankD: "In other words, it appears this sensor was likely optimized for speed at the expense of low ISO dynamic range." -- shouldn't it be? And there's no problem at higher ISOs, maybe even a little improvement. This sounds like exactly what the A9 should do.

In fact, this is just following Minolta's path. The Maxxum 9 was in many ways an inferior camera to the Maxxum 7, but the 9 was faster and more rugged.

To me, the real question is: will there be an A9S and A9R?

zeratulmrye: it'll all be free, done using OpenMemories. The main thing we're working on is TDCI (Time Domain Continuous Imaging), which we have implemented using CHDK. In TDCI, the camera captures a sequence of images which are converted into a continuous waveform per pixel. From those waveforms, virtual exposures representing arbitrary intervals (start time and shutter speed) are computationally rendered -- so you can render video at any framerate and shutter angle or manipulate what time interval a still image represents so that it captures the intended moment.

I recently published a single-shot method for reducing noise in raws: http://aggregate.org/DIT/ei2017KREMYslides.pdf I don't know offhand what info is available from the accelerometers (or perhaps current sensor shift?), but now you're starting to see why this stuff's important. For example, an accelerometer trace during the capture interval would define a blur PSF facilitating computational removal of motion blur....

Link | Posted on May 18, 2017 at 15:34 UTC
On article Sony a9: more speed, less dynamic range (666 comments in total)
In reply to:

ProfHankD: "In other words, it appears this sensor was likely optimized for speed at the expense of low ISO dynamic range." -- shouldn't it be? And there's no problem at higher ISOs, maybe even a little improvement. This sounds like exactly what the A9 should do.

In fact, this is just following Minolta's path. The Maxxum 9 was in many ways an inferior camera to the Maxxum 7, but the 9 was faster and more rugged.

To me, the real question is: will there be an A9S and A9R?

Well, Sony does have a very nice JSON interface for remote control.... It might be that the A9 has so much going on inside that they couldn't afford the extra "timing noise" (unpredictability) caused by running in-camera apps...?

Link | Posted on May 18, 2017 at 13:19 UTC
On article Sony a9: more speed, less dynamic range (666 comments in total)
In reply to:

ProfHankD: "In other words, it appears this sensor was likely optimized for speed at the expense of low ISO dynamic range." -- shouldn't it be? And there's no problem at higher ISOs, maybe even a little improvement. This sounds like exactly what the A9 should do.

In fact, this is just following Minolta's path. The Maxxum 9 was in many ways an inferior camera to the Maxxum 7, but the 9 was faster and more rugged.

To me, the real question is: will there be an A9S and A9R?

It depends. There seem to be some build improvements, added features (bigger battery, dual cards), and UI changes in the 9 that could justify the higher price for pros in the video and max. low-ISO quality markets. Personally, I think the A7RII is still the most versatile and I don't need the bigger battery and dual cards... and I do need the camera app support (working on making our own apps).

Link | Posted on May 18, 2017 at 12:01 UTC
On article Sony a9: more speed, less dynamic range (666 comments in total)

"In other words, it appears this sensor was likely optimized for speed at the expense of low ISO dynamic range." -- shouldn't it be? And there's no problem at higher ISOs, maybe even a little improvement. This sounds like exactly what the A9 should do.

In fact, this is just following Minolta's path. The Maxxum 9 was in many ways an inferior camera to the Maxxum 7, but the 9 was faster and more rugged.

To me, the real question is: will there be an A9S and A9R?

Link | Posted on May 18, 2017 at 11:46 UTC as 125th comment | 9 replies
Total: 1306, showing: 21 – 40
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