PIX 2015
Joseph S Wisniewski

Joseph S Wisniewski

Lives in United States Detroit, MI, United States
Works as a Speech and sensor scientist
Has a website at http://www.swissarmyfork.com
Joined on Jul 12, 2002
About me:

I've been in love with photography for over 40 years.

My favorite form of photography is macro, and much of my gear is of my own design.

I've done professional photography on and off for over 20 years.
Taught 8 years at Midwest Photography Workshops.
Designed 3 scientific digital cameras and 6 lenses.

Author of mImage and (coming soon to the App Store and Google Play) ColorForEveryone.

Comments

Total: 587, showing: 341 – 360
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In reply to:

NancyP: Joseph Wisniewski: "Breathing" - that is a new term to me. Could you explain what you mean? Optical diagrams I get, but you can't readily show these in comments.

Note that I said "if it were perfect". In reality, it both zooms and moves as it focuses. So, it might use zooming to account for 5 of the 7.7mm that it needs to focus from infinity to 1m, and use movements of some elements near tie aperture to pick up the other 2.7mm. The result, the angle changes, but only 1/3 as much as it would if you used an old-fashioned unit-focus design.

So, the 85mm f1.4 Nikkor is "better" for video than the 85mm f1.4 Cosina Zeiss Planar. The Nikkor is not free of breathing, but it breathes about 1/3 as much as the Zeiss.

Some lenses overzoom. The Nikon 70-200mm VR II is an example. It actually changes focal length from 85mm to about 59mm when it goes from infinity to 1.4m. That's 25.5mm outward, when it only needs 5.5mm. So it "overzooms" about 20mm, and ends up breathing worse than a unit focusing lens that would only have moved 5.5mm.

The older version 1 zoomed much less, and has much less breathing.

Direct link | Posted on Jul 14, 2012 at 20:06 UTC
In reply to:

NancyP: Joseph Wisniewski: "Breathing" - that is a new term to me. Could you explain what you mean? Optical diagrams I get, but you can't readily show these in comments.

A lens that changes focal lengths as you focus can partially or totally compensate for breathing. The older Nikon 85mm f1.8 D, for example, has an "internal focusing" mechanism that moves the lens's rear inner elements to alter the focal length of the lens when the camera tries to focus it.

Instead of racking out from 85mm to 92.9mm when you focus from infinity to 1m, it changes focal length. At infinity, it's an 85mm lens, 85mm from the sensor. At 1m, if it were perfect, it would zoom, becoming a 77.3mm lens at 85mm from the sensor. Since the "hole in space" is always 85mm from the sensor, the lens is always covering 28.6 degrees.

Direct link | Posted on Jul 14, 2012 at 19:58 UTC
In reply to:

NancyP: Joseph Wisniewski: "Breathing" - that is a new term to me. Could you explain what you mean? Optical diagrams I get, but you can't readily show these in comments.

Brendon's on the right track.

Breathing is an old movie term. Still photographers don't pay as much attention to it, but it's a real problem when you focus in to blur a scene for a transition, or cross focus between two people at different distances, to add emphasis to a dialog.

It means the angle of coverage of a lens changes as you focus. Even a "unit focusing" lens that doesn't change focal lengths when you focus breathes.

Let's pick on my 58mm f1.4 Voigtlander. It doesn't change focal length when you focus: it's always 58mm. So, at infinity, the lens is a "hole" 58mm from the sensor. On a FF camera, that's 2*arctan(43.3mm/2/58mm) = 40.9 degrees.

When you focus to 1m, the lens extends 3.6mm. That hole is now 61.6mm from the sensor. So, the angle of coverage is now 38.7 degrees, a very visible difference from the 40.9 you had at infinity. Stuff gets larger looking.

Direct link | Posted on Jul 14, 2012 at 19:46 UTC
In reply to:

Frenske: Depth of field: 0.0004m at 0.47m and f/2.8. LOL ... even at f/16 it is just 3mm. I am not sure the world really needs lenses like this.

You're both welcome.

Direct link | Posted on Jul 13, 2012 at 16:10 UTC
In reply to:

The Scurvy Dog of PR: I noticed they did not state in the specs, how much it weighs. At F2.8 and 19 elements, it must be substantial.

1.64kg, 3 lb 9.8 oz

http://sigma-photo.co.jp/english/lens/macro/180_28_os/#/specification

Direct link | Posted on Jul 13, 2012 at 16:08 UTC
In reply to:

Frenske: Depth of field: 0.0004m at 0.47m and f/2.8. LOL ... even at f/16 it is just 3mm. I am not sure the world really needs lenses like this.

Actually, teleconverters are common with long macro lenses, to get more working distance around "skittish" subjects. Shaw's "Closeups in Nature" has a lot of good information on that technique. That's one reason for an f2.8 macro.

A lot of us do extreme shallow DOF macro. I often use a Nikon 85mm f1.4 (76mm f1.4 at its closest focus) with a Canon 500D diopter. That's effectively a 66mm f1.2. That's another reason why people need lenses like this.

Zeiss makes a pair of f2.0 macros, a 100mm and a 50mm.

Now, if you know so little about the subject, you really shouldn't be getting so rude with people who do know about it, or ridiculing equipment manufactures. Instead, ask intelligent questions, like why would they make this? What would you do with it?

Direct link | Posted on Jul 13, 2012 at 13:41 UTC
In reply to:

GreginVA: I am 2 for 2 with dud Sigma lenses, including a 150mm OS Macro which will periodically decide to have problems with autofocus and with image stabilization. I won't buy any more Ford cars and I won't buy any more Sigma lenses, particularly when there are reasonable alternatives from Canon and Nikon. The specs for this lens look good, but Sigma does not have adequate quality control.

I'm 6 for 5 (one lens went in twice, for two unrelated problems).

The HSM died in my 30mm f1.4.

The 14mm had a problem with its own lubricants coating the glass elements, and, as it was out of warranty, Sigma promptly pronounced it irreparable, but a local shop fixed it.

My 400mm 5.6 went in twice: once for the AF mechanism, once for an internal element that came unmounted.

My 8mm has a focus problem that Sigma says (in tiny print, in the manual, no less) is normal for that lens.

My SD-14 died the second or third time I turned it on, and I returned it for "fitness for purpose".

Direct link | Posted on Jul 13, 2012 at 13:30 UTC
In reply to:

semorg: I'll wait an see if they are truly f/2.8 at the 1:1 ratio position or if the the 2.8 is at longer range. Also I would be curious about the diaphragm design and the kind of bokeh this lens can produce. For me the best 180 lens and probably the best lens created remains to be leica 180/2.8 apo.

This one, like my Nikon 200mm, is an internal focusing type: the focal length drops as you get closer to 1:1. WillemB says 117mm, which makes sense. 180mm f2.8 is a 64.3mm aperture, so 117mm at 1:1 is f3.64, which is a lot better than the 150mm does, a "conventional" macro that goes from f2.8 to 5.6 at 1:1.

@sirkhann, aperture is reduced (see "bellows factor") but light transmission (see "t stop") is unaffected.

Direct link | Posted on Jul 13, 2012 at 13:24 UTC
In reply to:

IcyVeins: Just wondering but why would you need f/2.8 for doing macro? Don't you usually want as much DOf as possible since you are focusing so close?

Willem, it's close to the length you need to avoid breathing. If your lens doesn't change focal length at all, you get "breathing in" when you focus in. Say you've got a FF camera. At infinity, the angle of view is 2*arctan(43.3mm/2/180mm) is 13.7 degrees. Now, simply extend to 1:1, and you've got a pupil 360mm from the sensor, and 6.9 degrees.

If your lens zoomed to 90mm when it hit 1:1, you'd have the original 13.7 degrees, "breathing free", but you'd have a short working distance.

I guess 117mm is a "happy medium", you breath from 13.7 to 10.6 degrees, but still retain about 200mm of "working distance".

Oh, and of course, if it held its 180mm focal length, it would need to extend an additional 180mm to reach 1:1. It's already 204mm long: a 384mm (15 inch) long macro would be very hard to handle.

Direct link | Posted on Jul 13, 2012 at 13:10 UTC
In reply to:

Pentax_Prime: Anyone notice that this is the only site that 'updates' you on 'Lytro'? (A company that has never actually released a product - nor made any sort of actual business sense.) Is this company Amazon owned or what?

You can't locate production figures, but you know the size of their waiting list?

"Dr Ng built this company in six years out of his award winning Stanford Dissertation"

An award winning dissertation is not a required ingredient for a successful company. I know someone who won an award for their dissertation in linguistics. It was about the variations in the articulation of consonants, based on analysis of modern speech recordings and early gramaphone recordings. (I helped with the math. I'm cited in more than one dissertation).

Direct link | Posted on Jul 11, 2012 at 20:28 UTC
In reply to:

Oahu Kamaaina: Here's an interesting link about the Dycam Model 1 digital camera released in 1990. It had 320x 240 resolution, held 32 pictures, fixed focus lens, and cost $995. [That's 1990 dollars]

http://www.cameracuriosities.com/2012_02_01_archive.html

I'm sure there were lots of comments by film photographers putting down the new technology then, similar to the comments in this blog. The Lytro camera may well fail, it's largely a proof of concept, but I'm surprised that the photographers who don't buy one aren't at least cheering their innovation rather than dissing their attempt to improve the technology.

"There are also 331 hits for the Leica R4 on eBay, if that's your criterion."

No, it's not. There are 10 Lytro cameras for sale, and my criterion is that this is high, for a camera that has so few units produced, over such a short time.

Of those "331 hits for the Leica R4" in your attempt at diversion, about 40 are for cameras, and some of those are collectables, like the gold-plated versions. Most of the hits are for brochures. 40 cameras isn't many hits for 1.6 million units produced over a 7 year period. Especially when the camera has been out of production for a quarter of a century and the only way to get one is on the used market (eBay, KEH, camera shows, etc).

Direct link | Posted on Jul 11, 2012 at 19:57 UTC
In reply to:

Oahu Kamaaina: Here's an interesting link about the Dycam Model 1 digital camera released in 1990. It had 320x 240 resolution, held 32 pictures, fixed focus lens, and cost $995. [That's 1990 dollars]

http://www.cameracuriosities.com/2012_02_01_archive.html

I'm sure there were lots of comments by film photographers putting down the new technology then, similar to the comments in this blog. The Lytro camera may well fail, it's largely a proof of concept, but I'm surprised that the photographers who don't buy one aren't at least cheering their innovation rather than dissing their attempt to improve the technology.

"But as I said earlier, "I'm surprised that the photographers who don't buy one aren't at least cheering their innovation rather than dissing their attempt to improve the technology.""

Why are you surprised about that? How can there be "cheering for their innovation" when there is no "innovation" to begin with? You summed it up yourself. After debunking the part about "a huge amount of data" and the part about "3D images" (because it doesn't have the stereobase to solve the occlusion problem) and the part about "all-in-focus images" (It does, after all, have a focus system), you're right back to your original statement, it's a "one trick pony". The one trick is "to make refocusable images", and the paucity of those in the wild shows that there is little demand for that one trick.

Direct link | Posted on Jul 11, 2012 at 19:45 UTC
In reply to:

Oahu Kamaaina: Here's an interesting link about the Dycam Model 1 digital camera released in 1990. It had 320x 240 resolution, held 32 pictures, fixed focus lens, and cost $995. [That's 1990 dollars]

http://www.cameracuriosities.com/2012_02_01_archive.html

I'm sure there were lots of comments by film photographers putting down the new technology then, similar to the comments in this blog. The Lytro camera may well fail, it's largely a proof of concept, but I'm surprised that the photographers who don't buy one aren't at least cheering their innovation rather than dissing their attempt to improve the technology.

That is not "clarifying". You're either being deliberately deceptive or innocently incorrect. I'll assume the second for the time being.

The Lytro takes a rather small amount of data, less than a typical P&S. It destroys over half of the 11mp that it actually gathers. (without moving to a hexagonal array sensor, a square grid sampling of a circular light field loses 30%, and their lack of proper AA corrupts at least an additional 25%. I've analyzed some Lytro files).

Sales figures can be estimated by the number of people you can locate using the product. You simply use the ratio of observed users to sold product for products you can get sales figures for.

Best estimate, they've sold under 1000 units.

Direct link | Posted on Jul 11, 2012 at 19:31 UTC
In reply to:

Oahu Kamaaina: Here's an interesting link about the Dycam Model 1 digital camera released in 1990. It had 320x 240 resolution, held 32 pictures, fixed focus lens, and cost $995. [That's 1990 dollars]

http://www.cameracuriosities.com/2012_02_01_archive.html

I'm sure there were lots of comments by film photographers putting down the new technology then, similar to the comments in this blog. The Lytro camera may well fail, it's largely a proof of concept, but I'm surprised that the photographers who don't buy one aren't at least cheering their innovation rather than dissing their attempt to improve the technology.

I think you've nailed the problem.

"The Lytro is a one-trick pony but it's a trick that no other consumer camera does."

Now, from your comments, it is apparent that you enjoy this one trick. From the lack of positive comments here, and all over the net, it appears that you are part of a very, very small crowd.

1990s digital cameras filled a need that was pretty plain to see, even back then. There were already reporters who came to news events with a van that had a developing system, scanner, and transmitter so that they could get images back to the paper quickly. Those people adopted $40,000 Kodak DCS-100 and 200 units, because they filled a need. Kodak had trouble keeping up with orders.

Heck, Ansel Adams saw something in a lab in 1978 that wasn't even portable, and he said it was the future.

Right now, Lytro appears to have fizzled. Sales are practically non-existent. Look at eBay. I checked yesterday, 10 low-usage Lytros for sale. People get tired of the one trick, quick.

Direct link | Posted on Jul 8, 2012 at 12:46 UTC
In reply to:

Pentax_Prime: Anyone notice that this is the only site that 'updates' you on 'Lytro'? (A company that has never actually released a product - nor made any sort of actual business sense.) Is this company Amazon owned or what?

Actually, Lytros aren't available on Amazon, they only do direct sales. But they most definitely have been released. A local photographer has one and loaned it to me for a couple of days. I was not impressed. They've been around long enough for a few owners to get tired of them: there are currently 10 of them on eBay.

http://www.ebay.com/sch/?_nkw=lytro

I will grant you the "nor made any sort of actual business sense" part. I've been saying that about Ng for years.

Direct link | Posted on Jul 8, 2012 at 02:33 UTC
In reply to:

sesopenko: Great product, botched marketing campaign. The whole "we have to catch the social media bandwagon" attitude they had was very misinformed and you could tell from the adoption rate. I think shareholders were expecting something like this being announced.

Aside from social media, what is the market for this thing? What real-world problem is it actually going to solve?

Direct link | Posted on Jul 2, 2012 at 13:22 UTC
In reply to:

chadley_chad: There were rumours Steve Jobs was keen to get involved. I think this brand needs someone like Apple to make it succeed. Anyone else will just f**k it up (IMO) - only Apple have the vision and capability to take this thing and create the defining camera ... as they did with the iPod, iMac, iPad etc. As much as you might hate Apple, you have to admit, they know how to make a product! Lets hope soon they turn their hand to the camera market (and what better start than Lytro!)

NB if the Lytro was half the price I'd buy one despite the limitations ... you know us camera buffs, we'll try most new photographic technologies just for the hell of it!

I wouldn't characterize the technology as "stupid", but that might be an appropriate, if rude, word for the current attempts to market it.

It delivers the ability to refocus at a terrible penalty in resolution and low light ability. It's a product without a clear purpose. Once you "explore focus" in a couple of images, you're done.

Direct link | Posted on Jul 2, 2012 at 13:19 UTC
In reply to:

Hugo808: Why don't manafacturers finish their cameras before selling them?

They did finish it. They added something beyond what it was when it was finished, to accommodate a lens that didn't exist at that time.

Direct link | Posted on Jun 20, 2012 at 13:11 UTC
In reply to:

dholl: Thanks, but I see no mention of whether the D800E has the same moire issues as the D800 in video mode. There is a confused debate about whether there is any difference (obviously with stills there is).

Can you shed any light on this?

> The two cameras will exhibit different characteristics.

Of course they won't. The AA filter operates on fractional pixel distances, about 3 microns. The pixel pitch for the video decimation is 3.5 pixels, 17.5 microns. That's the pitch that causes severe aliasing on both the 800 and the 800E. Like the review said:

"Here, though, the D800 and D800E perform all-but identically in terms of the amount of moiré visible in the final footage."

CameraLabTester? Right...

Direct link | Posted on Jun 12, 2012 at 18:02 UTC

"This seems like an odd way of doing things; why not just remove the filter altogether?"

One of the two LiNbO3 filters serves as the sensor cover glass, it's not part of the stack. So, the only way to remove it is to make a change on the chip manufacturing line, which means new part numbers, validation, etc. for sensor and circuit board.

Altering the second LiNbO3 filter, the one in the stack, is much easier. You don't have to change as much stuff, stock two kinds of chip, rerun validation, etc.

Direct link | Posted on Jun 12, 2012 at 17:50 UTC as 18th comment
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