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

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In reply to:

j12tone: Photographs are not real.

http://www.jeffreysward.com/editorials/pnotreal.htm

https://luminous-landscape.com/abstraction/

It always used to drive me nuts when people would look at one of my photos and say "that's Jim" or somesuch, because in no way was it ever anything more than how I envisioned Jim. A camera is a device for creating a model of scene appearance. The photographer always has control of the scene appearance by manipulating the scene, exposure parameters, and postprocessing.

This (rather shallow) National Geographic article doesn't quite come out and say what it really should: photography can span a broad spectrum from abstract art to evidence, and National Geographic sees itself as not being in the business of publishing art. They are most interested in feature reportage, which is properly nearer the evidence end of that spectrum.

A photographer legitimately can produce images that fall anywhere in the art-to-evidence spectrum -- as long as the work is correctly classified and complies with the rules of the particular publication venue.

Link | Posted on Jul 6, 2016 at 01:23 UTC
On article Photographing fireworks: The basics and then some (66 comments in total)

Excellent little article. One more trick:

Capture a photo WITHOUT any fireworks exploding.

Ok, I don't really have to tell you to do that, because you'll naturally miss every so often... but the cool trick is that you can use a separate exposure (perhaps with very different exposure settings) like that aligned with an image that shows fireworks to fill-in the background to whatever level you wish by combining the exposures in post. Especially if you're using a tripod or other solid mounting for your camera, it's very easy to get a clean exposure of the background -- in fact, you might even want to get that shot before they turn the lights off for the show to start. Fireworks might look more impressive in person with everything else dark, but you really are shooting "skyscapes" and all the rules about foreground, etc., for landscape photography still apply.

Link | Posted on Jul 3, 2016 at 17:58 UTC as 18th comment
On article The price is right: Canon EOS Rebel T6 / 1300D Review (415 comments in total)

"In short, with the T6, Canon has gathered up various components it had lying around on the shelf from Rebels past and put them together in an aggressively priced bundle."

In case you hadn't noticed, that's been Canon's way to build camera equipment for a very long time -- no more than one or two "new" things in any model. It is why CHDK and ML can work, and it gives their products very low engineering and parts cost... and I bet their profit margin is decent even on this $500 model. Note that the bundles place the 75-300mm at $50 price!

Link | Posted on Jun 30, 2016 at 02:34 UTC as 40th comment
On article Sony Alpha SLT-A68 real-world samples (120 comments in total)
In reply to:

PORTRAIT: I had A55, the first generation DSLT cam.,Amazing features at that time: 10FPS,FAST LV AF,IBIS,just to name fews..Anyway,I had wonderful memories as well, (weddings, family event, etc..)Never let me down, except for these little "details":
.1 The infamous video heating issue,(basically unusable if you were planning to shoot more than 10/15mns. above 25c..And W/o having the cam quitting on ya, just when you were shooting..;)...and as far as I understand, the new A6300 has the same issue?.
.2 Flash system is mediocre at best (very unreliable!..nothing can beat Nikon system,my D40X has still an incredible metering/flash system..!)
3.Lenses, just Okish, (unless you are willing to spend $$$ with Zeiss be my guest..)but luckily, Minolta has a plethora of old vintage very cheap ones,but again, there where always the downside of the PF issue with many of those lenses...Overall I found the kit lens inferior even compare to my Nikon 18-55mm...,So Sony for these "few" reason I'M ..OUT..;)

I still have my A55... and A350... and A100. All quite good cameras and the A68 is in most ways better. It just isn't exciting by Sony standards, while the E-mount bodies have been doing very exciting things. Although I'm mostly using manual focus on E-mount bodies these days, pretty much the only AF glass I use on my A7II is old Minolta AF glass, and it is cheap and works quite well. For example, it cost me under $20 for my A-mount Sigma 28-200mm, which on an LA-EA4 makes a great AF walk-around lens for my A7II.

Anyway, the point is that the Sony A-mount line, with IBIS and a ton of good older glass at cheap prices, is still at least competitive with everything except Sony's E-mount line. Sony needs to either push A harder or smooth the path from A to E (e.g., by making a cheap LA-EA3.5 -- supporting screw-drive AF like an LA-EA4, but using the on-sensor PDAF like an LA-EA3).

Link | Posted on Jun 29, 2016 at 14:32 UTC
On article Hands-on with Hasselblad X1D (802 comments in total)

Time to add a Hasselblad forum. There will be enough users for this. :-)

Link | Posted on Jun 23, 2016 at 10:47 UTC as 106th comment
On article Hands-on with Hasselblad X1D (802 comments in total)
In reply to:

guyfawkes: Can't see on the Hasselblad site any reference to IS, in-body or lens, nor in-built sensor cleaning. Or does the physical size of the senor preclude such niceties?

The body size would make IBIS near impossible. Look at the card slots, the battery, then the open front to see the sensor position. There's no space in this thing! In fact, I bet the touch screen was done partly to save space. This looks on par with the densest Sony or Samsung bodies... very impressive. I wonder if they'll have the Sony multi-shot anti-blur -- that could be a nice solution here.

Link | Posted on Jun 23, 2016 at 10:42 UTC
On article Medium-format mirrorless: Hasselblad unveils X1D (1190 comments in total)
In reply to:

ProfHankD: Looks really good as a mirrorless product... except the mount. The mount barely looks big enough to handle the 50MP 44x33mm sensor -- which really isn't quite "medium format." I think that's a mistake. I would have aimed to at least handle a future sensor in H's traditional 6x6cm format with the same lens mount. The "0.8x focal length multiplier" listed above is also just plain silly... it is actually more correct to think of it as 1.5x crop of the 6x6cm format.

I will also say that it literally LOOKS good, traditional H styling rather than "dolled-up" wood add-ons. I expect they'll actually sell these. :-)

Rest assured, NAwlins Contrarian, that sensors bigger than 44x33mm are going to be reasonably cheap very soon. However, I'm biased. In my research, I've been working toward a cheap 500MP 4x5" sensor for some years now... which I guess ogl would define as "middle format"? ;-)

Link | Posted on Jun 22, 2016 at 15:37 UTC
On article Medium-format mirrorless: Hasselblad unveils X1D (1190 comments in total)

Looks really good as a mirrorless product... except the mount. The mount barely looks big enough to handle the 50MP 44x33mm sensor -- which really isn't quite "medium format." I think that's a mistake. I would have aimed to at least handle a future sensor in H's traditional 6x6cm format with the same lens mount. The "0.8x focal length multiplier" listed above is also just plain silly... it is actually more correct to think of it as 1.5x crop of the 6x6cm format.

I will also say that it literally LOOKS good, traditional H styling rather than "dolled-up" wood add-ons. I expect they'll actually sell these. :-)

Link | Posted on Jun 22, 2016 at 13:43 UTC as 270th comment | 4 replies
On article Sony warns against use of unauthorized third-party apps (183 comments in total)

Well, that is one possible reaction from Sony. It is reasonable to warn folks that actions of "unblessed" apps are not covered by any Sony warranty, which I think is what they're doing. A better reaction would be to follow that warning with a statement to the effect that they will open the camera app development interface and establish a 3rd-party app certification program... like some of us have been suggesting ever since they started running Linux inside their cameras.

Link | Posted on Jun 22, 2016 at 11:27 UTC as 18th comment
On article Hasselblad to announce 'game changer' next week (457 comments in total)
In reply to:

EthanP99: Its a medium format mirrorless.

The 50MP Sony sensor has the advantage that MOST SLR LENSES CAN COVER IT in various different format crops. We'll see.... ;-)

Link | Posted on Jun 17, 2016 at 22:31 UTC
In reply to:

pulsar123: So where is the boundary between "lenses" and refractor telescopes? The Zeiss 1700mm f4 is so massive it looks more like a large telescope. Then one can go all the way to the largest refractor telescope currently in use, Yerkes Observatory's 19,400mm f19 "lens" (https://en.wikipedia.org/wiki/List_of_largest_optical_refracting_telescopes).

Actually, the difference is an interesting question. I've always thought of telescopes as being defined by the use of an eyepiece, although most serious telescopes have cameras mounted on them -- often in addition to an eyepiece. Certainly, I think of my 1250mm telescope as also being a lens....

Link | Posted on Jun 17, 2016 at 05:34 UTC
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

Leandros S: "Out of curiosity, is there a particular challenge with designing a lens that works out as exactly f/1.2000, say?"

Nothing is ever exact in engineering; there is even a slight copy variation in focal length for most lenses, and that would alter f/numbers (which are ratios of focal length/aperture diameter). Actually, stops go as powers of the sqrt(2), so f/1.4 should really be f/sqrt(2). The "precisely correct" value for f/1.2 depends on if you expect it to be 1/3 or 1/2 stop faster than f/sqrt(2)....

Link | Posted on Jun 14, 2016 at 12:32 UTC
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

dopraopat: The lensmaker is responsible only for producing a product that is as advertised, not for how much benefit you really get using that product on your current camera. I'm also sure there eventually will be sensors without microlenses that will be able to make somewhat better use of such ultra-fast lenses. The question should be "is this lens worth its price in terms of what images it will allow you to create?"

That's hard to judge at this point, because we don't even know the price... but I suspect it will be a viable photographic tool because it is coming from a company that makes some pretty scary special-purpose optics (see their website): this is very unlikely to be a poorly-designed or shoddily-built optic. As for the marketing emphasis on it being f/1.2, well, that's how marketing works... especially if you are not a well-known brand and your marketing team speaks in somewhat broken English. ;-)

Link | Posted on Jun 14, 2016 at 12:17 UTC
In reply to:

ldog: Uh guys, ever hear of the superb Voightlander 35mm f1.2? It covers FF and has been on the market since around 2011.

It is much harder to make a 35mm f/1.2 with a long enough back focus for a DSLR. I wouldn't expect they'll sell many of these in E-mount -- I think most E-mount users would buy the lens in Canon EF or Nikon F mount and adapt it to E, because that's more flexible... even allowing use of a focal reducer. Actually, I don't understand why modern lenses like this don't offer M42 or T mount versions for flexibility across SLR mounts.

Link | Posted on Jun 14, 2016 at 09:46 UTC
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

The microlenses in your camera are not the lensmaker's problem. However, it is difficult to know exactly what to expect from f/1.2. Just rounding the f/number to two digits makes it unclear if f/1.2 is 1/2 or 1/3 stop faster than f/1.4. There is also the fact that the bokeh (OOF PSF) size for a given level of defocus can vary somewhat depending on the design of the lens. The effective f/number issue gets even more complex in that T/numbers are what determine the amount of light actually transmitted -- different lenses can have significantly different loss due to internal reflections, etc.

In any case, I expect this is a very fast 35mm lens that is probably ok wide open and very good stopped down a bit. If you want to get really speed crazy, an SLR -mount version also could be used on a mirrorless mount focal reducer to get something like an APS-C 25mm f/0.9.

Link | Posted on Jun 14, 2016 at 09:38 UTC
In reply to:

Greg VdB: That's a lot of camera for little money. As a Pentax, it will sell in smaller amounts than similar offerings from bigger brands, even if many specs are better. For that reason, I hope DPR makes it a priority to review the K-70 as soon as it becomes available. Not just to give it well-deserved recognition, but also to put pressure on other manufacturers to step up their game. (and no, I don't shoot Pentax)

For most of my lifetime, Minolta and Pentax were the big innovators in the camera industry... well, Minolta is now Sony and Pentax is now Ricoh. I'm a big fan of mirrorless, but I think Ricoh's latest APS-C and FF offerings are the most appealing DSLRs yet produced -- and their pricing is very aggressive. It's getting harder to understand how Nikon, and especially Canon, keep market share... but honestly I found that hard to understand as far back as the 1970s. ;-)

Link | Posted on Jun 9, 2016 at 10:52 UTC
On article 2016 Roundup: $1200-2000 ILCs part 1 - Crop-Sensor (180 comments in total)
In reply to:

whiteheat: I'm not an E-mount user/owner, but what, no Sony entry in your line up at all?

... and this is one more reason why grouping by price is always a little odd. Beyond that, there is the question of which price with what (if any) lens. The D500 only makes this range without a lens, while the X-T1 doesn't top $1000 without a lens. Overall, this is not a very consistent, complete, nor useful grouping. :-(

Link | Posted on Jun 8, 2016 at 13:15 UTC
On article Mosh pits and sunsets: Shooting with the Panasonic GX85 (146 comments in total)
In reply to:

ProfHankD: It's not cheap, but it is a really nice camera with lots of features... and an older, too-small, sensor. It is a real pitty that micro4/3 wasn't designed to accommodate a range of sensor sizes up to FF....

Sean65: NO, it has always been the entire "system": http://www.four-thirds.org/en/microft/

Beyond that, the micro4/3 sensor IS the 4/3 sensor -- the micro aspect is entirely about the shortened flange distance and system-level tweaks made leveraging live-view and video support (and in many of the earlier documents, CDAF). Here's the one image summary: http://www.four-thirds.org/en/common/img/c_mft_benefit_vi_03.gif

Link | Posted on Jun 8, 2016 at 11:27 UTC
On article Mosh pits and sunsets: Shooting with the Panasonic GX85 (146 comments in total)
In reply to:

ProfHankD: It's not cheap, but it is a really nice camera with lots of features... and an older, too-small, sensor. It is a real pitty that micro4/3 wasn't designed to accommodate a range of sensor sizes up to FF....

JimW-203: 4/3 isn't even close to 1.33 inches in any useful dimension; the image area has a 21.6mm diagonal. Apparently your yardstick is no more than 23 inches long. ;-)

Incidentally, a 1" sensor isn't really 1 inch either; it is around 16mm diagonal. APS-C is around 28.3mm (which still is less than 1.33") and FF is around 43.2mm. Most mounts currently used for APS-C also can support FF sensors; there is no reason why micro4/3 couldn't other than bad planning. And yes, I and MOST folks are buying interchangeable-lens cameras with larger sensors... that was my point: micro4/3 mount locked into too small a sensor, and that's really the primary limit on what would otherwise be very good cameras from Panasonic and Olympus.

Link | Posted on Jun 8, 2016 at 07:27 UTC
On article Mosh pits and sunsets: Shooting with the Panasonic GX85 (146 comments in total)
In reply to:

ProfHankD: It's not cheap, but it is a really nice camera with lots of features... and an older, too-small, sensor. It is a real pitty that micro4/3 wasn't designed to accommodate a range of sensor sizes up to FF....

RedDog: read that long ago; it's not relevant. It doesn't matters if individuals take that upgrade path or not... the market has and probably will for a while.

The traditional way that semiconductor chip fab gets better is that density gets higher -- as opposed to chip area increasing. The 4/3 sensor size was a sweet spot and it was reasonable to expect density increases would make it continue to be a cost-effective choice near the leading edge. Instead, the market split into smaller and bigger sensors, and 1" and 4/3 are in the awkward in-between. It has a lot to do with optics too; 4/3 is way too big for the exotic optical approaches used in cell phones, but more conventional optics can do better with a somewhat larger sensor. Despite 4:3 vs. 16:9 aspect ratio, micro4/3 has been prospering mostly for video, which is currently less demanding of lens resolution... but I think those days are numbered too.

In sum, wouldn't Olympus and Panasonic bodies with FF sensors be cool?

Link | Posted on Jun 8, 2016 at 02:58 UTC
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