Joel Halbert

Lives in United States Tucson, AZ, United States
Works as a Engineer
Joined on Jul 4, 2003

Comments

Total: 149, showing: 1 – 20
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On article DPReview TV 'best and worst' awards in pictures (117 comments in total)
In reply to:

Class A: Regrettable that a product like the Sigma 85mm F1.4 DG DN Art is awarded a "the best" status, even though it deliberately features significant distortion that has to be corrected via software.

The video even makes the false claim that the lens has no "optical downsides" despite its small size. FWIW, the distortion is not the only issue, but there is also considerable "cat's eye" bokeh.

If the claim were true, what would it say about all the big and heavy glass? Is the idea that these are just made big and heavy to impress but that optical quality had nothing to do with implying these attributes?

FWIW, I fully realise that "best" need not always be "best optical quality" -- there are other dimensions to consider -- but the negatives should at least be pointed out instead of being omitted or even downright declared as being absent.

I had thought this argument was finally retired, but apparently not.

If you believe that the lens performance, relying on intentional, supplied and executed-by-default algorithms, is not genuine -
Then I hope your primary automobile is at least forty years old. If not, then perhaps you could march out to it, open the hood, disconnect all of the engine management processors and report back as to how well it works in its un-computer-corrected state.

Same for pretty much any kitchen appliance you have, and on and on.

Why should modern lenses be considered independently of their associated processing algorithms (really outside the context of their design purpose) unlike every other piece of equipment?

Link | Posted on Dec 6, 2020 at 20:22 UTC
On article DPReview TV: Leica Q2 Monochrom review (57 comments in total)
In reply to:

Daryl Cheshire: Question about the 50mm crop, will a photo taken with the wide angle lens still be a wide angle shot even if cropped?
It might be less noticable perhaps. You could take a portrait and the person will have a big nose, so will the 50mm crop still have a big nose?
Given it’s a fixed lens for this camera, the lens might be crafted to be a 50mm in the centre so such distorsions might be reduced? (is this possible?)
I admit I might have missed something.

Ran out of space to make these points that follow the prior comment:

So a wide-angle lens tends to result in "big-nose" portraits only because it encourages you to stand too close when taking the picture. If you resist this temptation and stand about 6 feet (2m) away, then later crop away the unwanted wide background portion, you'll get a perspective that is correct and natural for typical portrait image viewing.

A mild-telephoto (60mm- to 90mm-equivalent) is considered a "portrait" focal length simply because it encourages you to stand about the right distance away, while giving you a shot that fills about the right amount of the frame with the subject's head-and-shoulders portrait.

If you get the Q2 or a similar fixed-wide-angle camera, you simply need to avoid the temptation to get too close to portrait subjects and similar perspective-distorting traps. The in-camera crops can help with this, but they're only a helper tool - you can do it yourself: stand back and crop later.

Link | Posted on Nov 22, 2020 at 04:56 UTC
On article DPReview TV: Leica Q2 Monochrom review (57 comments in total)
In reply to:

Daryl Cheshire: Question about the 50mm crop, will a photo taken with the wide angle lens still be a wide angle shot even if cropped?
It might be less noticable perhaps. You could take a portrait and the person will have a big nose, so will the 50mm crop still have a big nose?
Given it’s a fixed lens for this camera, the lens might be crafted to be a 50mm in the centre so such distorsions might be reduced? (is this possible?)
I admit I might have missed something.

The big-nose issues, and other such perspective distortions, are a function of the distance from the camera to the subject. Or more precisely, the difference between the distance from which the picture was taken, compared to the distance and magnification at which the image is viewed.

General-purpose wide-angle lenses don't create the fun-house perspective distortion by themselves, nor do telephoto lenses create the familiar distance-compressing distortion by themselves. As stated above, these are due to a mismatch of your image-viewing perspective compared to the original shooting perspective.

Whatever the focal length of the original shot, the final image will look normal (and actually most natural) if you ensure that ratio of your viewing distance compared to image size is the _same_ as the ratio of the original shot. If you put your eye very close to a "big-nose" portrait, the big-nose effect will disappear and you'll feel that you're just standing fairly close the person's face.

Link | Posted on Nov 22, 2020 at 04:20 UTC

It's easy to understand that the "regular" camera app isn't convenient for quick photo or scanning work from various other apps.

Without weighing in on the freedom / choice / business / politics angles (which are all legitimate), it seems to me that Android should then provide new "modes" of camera operation, i.e. the stock app can be invoked in various simple or special-purpose modes by the calling app. It doesn't have to be the main camera interface with its stock resolution and photo/video settings and controls.

Certainly Google's choices still wouldn't answer all objections, but at least they should try to accommodate various predictable use cases.

Link | Posted on Aug 22, 2020 at 20:01 UTC as 13th comment
In reply to:

Gesture: What other kinds of planets are there?

.
Planet X
Lost Planet
Planet Gear
Bath Planet
Planet Hollywood

Well, seriously, there are "rocky" planets like Earth and Mars , gas giants like Jupiter and Saturn, ice planets like Neptune and the unfortunately demoted Pluto. There could be molten rock planets (lava) but we don't have any.

I found this Wikipedia article giving lists of planetary types by different classifications, I hope it doesn't contradict my lists above.
https://en.wikipedia.org/wiki/List_of_planet_types

Link | Posted on Jul 26, 2020 at 19:24 UTC

I always heard that porchature is best done at a a distance of six feet or more.

Link | Posted on Apr 16, 2020 at 17:32 UTC as 29th comment | 1 reply
In reply to:

SafariBob: At what point do they cease to be cameraphones and become phonecameras, thus providing a resurgence of the compact camera

@McArchive

"Zo, Maxwell Schmart, vunce again, you are my prisoner!"

"Not so fast, Siegfried! At this very moment you're surrounded by an army of tech reviewers. Your every move is being tracked by a Korean S20 Ultra 108 MegaPixel multi-focal optically stabilized autofocus camera with real-time 8k data uploaded directly to CONTROL headquarters at 5G speed!"

"Ha! You sink I'm a dummkopf? Every-vun knows ze C-AF is beta, ze firmvair ist kaput. It tracks nussink, it is uzelos!"

"Yes well - ah - Would you believe ... you're about to by cyber-bullied by some really mean teenagers on Twitter?"

"This is KAOS!" Ve don't _Tweet_ here! You vil be locked in a cell mit Schtarker, he vil torture you until you give up ze akzess codes...."

(Chief and 99 bust in the front door, a shoot-out ensues with no one injured, Siegfried escapes out the back door...)

(fade to Anacin commercial)

Apologies to all the younger members. The above is only for those who remember.

Link | Posted on Mar 2, 2020 at 06:05 UTC

I enjoyed the video. But I think it's only fair (to the now-mostly-retired Pentax engineers who designed this system), to emphasize a point that only a few others are making:

In this experiment, the lenses are being used in a way never intended. Not "wide open" but beyond that. They're really wider than f/2/8 but were designed to be used with the Auto 110 body's built-in shutter/stop that controls the opening. Optically, it's no fair to go without the stop that makes them f/2.8 as engraved.

If you went inside a modern lens and removed the aperture mechanism including associated rings and baffles, you'd be shooting through edges of the elements and the sharpness would take a noticeable hit. I think that's part of the story here.

Though perhaps not razor-sharp, I think their reputation is going to suffer unfairly because of these stop-less adapters on digital cameras. By adding various stops, you'd find the sharpness is better at actual f/2.8, probably much better at f/4 to f/5.6.

Link | Posted on Mar 1, 2020 at 17:10 UTC as 35th comment | 3 replies
In reply to:

Kubicide: Suspect the context may be wrong in the Bloomberg's story as the impact to a 3D stacked array, and separately manufactured DRAM, can only be with one of manufacturing capacity and / or specialized production resources, and not of the implied availability of 'memory chips' themselves. One does not simply take DRAM wafers, or chips, and add them to imaging focal planes.

@Kubicide
"One does not simply take DRAM wafers, or chips, and add them to imaging focal planes"
Say whaaaat? Haven't you seen a real sensor fab? Looks just like the Willy Wonka production area except the little men all wear white outfits and masks. There's a big metal funnel over a shiny boiler vat, where they pour in the ground-up DRAM chips they diverted from the PlayStation production line. It goes glug-glug-pfffft, and extra image-buffer memory gets mixed right in! In another corner, they chop up unsold Minolta Maxxums from the warehouse they bought, that gives them a good sprinkling of Phase Detection points. Sliced Jenga blocks are the perfect ingredient to build the Stacked Sensor architecture. Leftover advertising brochures put the BS in the BSI. It's all very high tech, trust me.

Link | Posted on Feb 20, 2020 at 04:04 UTC
In reply to:

dmanthree: Beautiful lenses whose sharpness depends on an antiquated focusing system?

1. Note that the triangulation base-length of the M rangefinder is quite a bit larger than its the equivalent base-length of TTL phase-detect AF. This is a fundamental advantage.
2. There is an off-line mechanical-optical path (lens cam to cam follower to prism angle) that has to be calibrated, but this has stood the test of time in terms of accuracy and reliability. Mirror-AF-[D]SLRs also have a calibration requirement, though with fewer links in the chain.
3. The ability to manually focus, and to detect the in-focus setting with speed and accuracy is noticeably better than with a focus screen.
4. One feature that is under-appreciated is the power of the focus tab for pre-setting focus.

Having made those points, there is little question that modern AF is much faster and, if finished-off with a CDAF final adjustment it is inherently more robust for accuracy. But the mechanical RF system, especially the Leica one with its sharp-edged RF spot, works extremely well in practical use.

Link | Posted on Feb 16, 2020 at 19:48 UTC
In reply to:

tkbasic: Since this is an Amzon owned site, I checked Amazon to see what people are buying.
Under the category of "Camera and Photo" where Film, DSLR and mirrorless cameras fall,
#1 Fujifilm Instax Mini Instant Film
#2 Wyze Smart home camera
#3 Wyze Smart home camera
#4 Wyze Smart home camera
#5 Fujifilm Instax Mini Instant Film
#6 GoPro Hero8
#7 is Polaroid film.

FujiFilm has 8 of the top 50 products, Polaroid has 4, and there is a Kodak single use film camera.
The only ILC related product in the top 100 is a Canon 50mm lens. No cameras (there are none in the top 250).

The best is, Amazon ranks being messed up as they always are, the #1 digital camera is a "Kodak FunSaver 35mm Single Use Camera".

neilt3, I didn't see that tkbasic claimed anything about "SLR cameras", not implied anything about used film-based equipment used or new. He said that there are no ILC cameras in the top 250. (essentially meaning digital interchangeable-lens cameras, DSLRs and Mirrorless these days).

The real point , I think, is that photographic-hobbyist items are almost completely missing from the top "Cameras & Photo" products. Security cameras, action cameras, instant and party-event cameras & film, and various accessories make up this most of this broad market category.

I understand your point about purchase venues, but my guess is that the essential market-composition conclusion wouldn't change very much even if you surveyed all retail outlets and not just Amazon.

Link | Posted on Feb 8, 2020 at 20:31 UTC
On article Panasonic Lumix DC-S1H 4K sample reel (102 comments in total)
In reply to:

tkbasic: A big thanks to Panasonic for elevating ILCs to what they've become for video. For 10 years since the GH1 they've been ahead of everyone else (the GH1 and GH2 hacks were a big help). The S1H again shows this.
It is clearly the best we have today, although Fujifilm and Canon have some interesting cameras for video too. Nikon's RAW video has been disappointing so far, but they are trying.
Don't look for any Sony DCI 4K video like this one. Sony has fallen far behind and is no longer in the conversation by refusing to offer DCI 4K, 10 bit video, 4:2:2 or higher, or a bit rate above 100Mbps (both Panasonic and Fujifilm offer 400Mbps)

tkbasic, I understood Jams Stirling's comment and did not see it as a shot at Panasonic. He was simply observing that there is a _potential_ conflict or at least a consideration of product segmentation for companies that have both a professional video equipment line and a hybrid/ILC camera line. How this _potential_ conflict is handled is then up to the company. Panasonic has done a good job of pushing the hybrid/ILC capabilities despite the fear of pro-video product cannibalization. This conflict has been acknowledged in interviews published on DPR etc.

James was saying that Nikon doesn't have this issue to grapple with. Of course it's not the only factor, probably not even the main one, that determines the development track for video features. The countervailing advantage for pro-video companies (Panasonic, Sony, Cano) is that they also have product definers and designers who know all about video and its sub-markets.

I don't see the topic as an attack on Panasonic.

Link | Posted on Jan 22, 2020 at 17:47 UTC
In reply to:

Verto: Looks great... thank god they fixed the grip. Unfortunately now that’s it’s 61 megapixels you have diffraction past F5.6. Shooting landscapes past F8 you’ll definitely notice it on screen and in print. No thank you.

This is not correct. Having more pixels doesn't make the picture worse and it doesn't make your lens worse, not at f/8 or any other aperture.

It just means that the camera can resolve more detail. So instead of being limited by the camera to a certain level of detail, it becomes more likely that the limit is coming from the lens, or from tiny vibrations, or from turbulence in the air etc. Diffraction will be no more visible "on screen and in print" than it was before, you'd simply have to pixel-peep harder to see it.

Saying "no thank you" because of that is like saying "no thank you" to a gift of $200 vs. $100, because you're afraid that the $200 might lead you to waste more money.

Link | Posted on Jul 16, 2019 at 20:06 UTC
In reply to:

Sara Valentine: In musical nomenclature, fortissimo is denoted in shorthand by 'ff' and pianissimo as 'pp', so this should be the Sigma ffpp if we're going to proceed with this 'fortissimo, pianissimo' tagline. Furthermore, a single 'f' is shorthand for "forte" which is a degree lower in loudness to fortissimo. A single 'p' is shorthand for 'piano' which is a degree higher in loudness to pianissimo.

Are we lost in translation?

Sara, you're right and you might also say that if fp in music notation really stands for fortepiano, well that is really the original full name of the instrument that we call a piano. So optimistically, Sigma's concept would become as popular and well-known as the piano. But the word play is being stretched pretty far.

Link | Posted on Jul 11, 2019 at 21:44 UTC
In reply to:

left eye: How do you attach an ultra useful tilting EVF?

Totally on the design-table from day one with MILC's, optional EVF's possible where optional OVF's on DSLRs are not. It's so genius that an EVF can be optional, also as there's no direct light path (as with OVF) the EVF can tilt and rotate with ease, again genius, a great asset with MILC's.

Oh but this camera missed this in-built flexibility, maybe the piece of paper on design-day one slipped onto the floor by accident - and no one was intelligent enough to remember what the flexibilities of MILCs are.

Or they just think, 'film', 'ok that means external monitor', let's kill off the main genius of MILCs - EVFs; dumb move.

The greatest camera at present is the GFX 50S with EVF tilt-adaptor. Better than any camera I've ever used, not just the 51MP sensor or the stellar lenses but that tilt EVF - is a joy, and so easy for a manufacturer to incorporate - just some electrical contacts on top of the camera.

Right, the eyepiece is a magnifier box attached to the rear of the camera for viewing the LCD, somewhat like a Clearviewer or I think the Zacuto attachments. No obvious coupled EVF interface as existed for Olympus Pen and Panasonic GF MFT bodies.

Run the promotional video and stop it at T equals 35 or 36 seconds approximately, to see a pretty good view of the attached rear-LCD magnifier.

Link | Posted on Jul 11, 2019 at 11:57 UTC
In reply to:

Naveed Akhtar: Very promising update .. thanks Panny!

Really wish if the AF-ON could be customised. Where you can specify the focal-range in settings with minimum and maximum distance it can only focus.

MikeRan - I don't think the near vs. far thing is to tell the AF which way to start moving (that's a thought conflated with the while explanation of DFD-enhanced CDAF). I think it's for telling the AF whether near or far subjects are most important. For example, whether to jump away from Subject A when Subject B walks in front of A.

Link | Posted on Jul 1, 2019 at 20:55 UTC
In reply to:

Turbguy1: I'll wait for f64.

Ooops! Can a photon get through that small a hole??

The answer is, it probably can but its destination on the other side is uncertain.

Link | Posted on Jun 26, 2019 at 17:23 UTC

The basketball animations suggest to me an immediate application: Edit the instant replay clip to win the argument with the refs every time.

Link | Posted on Jun 19, 2019 at 17:03 UTC as 15th comment
In reply to:

ZeBebito: Just take the F from Shiftcam and that's what this is. Nuff said.

Well if it doesn't work for you, then you simply can shift it - to the shift-can.

Link | Posted on Jun 13, 2019 at 06:12 UTC

The name "Vario..."is confusing because normally this prefix is reserved for variable-FL (zoom) lenses. What I actually see in one photo is the text "SA-VARI", not "Vario". Not that I know what that means either.

Interesting but eccentric products. I wish him the best and would not criticize him, he seems to be doing this as an experimental hobby and not as a flim-flam plan. I might enjoy meeting him but I've seen other small-shop lenses that are more interesting IMO (e.g. the Yasuhara super macros with built-in lighting).

Link | Posted on Jun 13, 2019 at 06:07 UTC as 25th comment | 1 reply
Total: 149, showing: 1 – 20
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