Some good news from Adobe - in a previous post, I reported that the new Adobe "V4" camera profiles broke the Adobe profile editor, a tool a lot of photographers depend on to get accurate color. Well, Eric Chan, who is on Adobe's Camera Raw team, has gone on record that the profile editor will be updated. See here.
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Adobe Lightroom 3.6 and Adobe Camera Raw 6.6 final is now out, with new fourth generation "V4" camera profiles. Unfortunately, it turns out that the V4 profiles break dcpTool. Here's the story:
For a while now, the Adobe folks, notably Eric Chan, have been working away at building better camera profiles. Theses profiles are intended to address a problem with some cameras, when used with earlier generation profiles, that could result in highlight banding. This was especially with some of the high-end Nikons e.g., the D3, D700, D300, etc. Back in January, Eric posted a set of beta profiles, called the "V3" profiles that addressed the banding issue. However, they required that exposure be offset by half a stop in Lightroom/ACR. A bit inconvenient, and not really what you want in a production environment.
With Lightroon 3.6/ACR 6.6 Adobe have introduced a new set of "V4" profiles that sort out the banding issues that older profiles had, but don't require the manual half stop offset. The good news is that most people seem to like the new profiles a lot.
The bad news is that the new profiles break both dcpTool, and Adobe's Profile Editor. The reason for this that the "V4" profiles include some new tags that neither product understands. This was confirmed by Eric in a thread on the Adobe forums. Also, I took a look at the profiles, and found three new tags:
Exif 0xc7a4 : 1
The middle tag, rather notably, is exactly the half stop manual offset that the old V3 profiles required, so I'd guess that basically this just automates the old offset procedure.
Exif 0xc7a5 : -0.5
Exif 0xc7a6 : 1
Digging around, it turns out that the problem with dcpTool and the new profiles was noticed by Vit Novak, but he didn't contact me, and I missed the post in which he mentioned the problem.
Unhappily, the new tags are not yet documented by Adobe, and are not yet part of the DNG SDK. Eric has said that Adobe are "working on" a new DNG specification (presumably to be 1.4) and a new version of the SDK. But no word on an expected date.
I'll update dcpTool once the new specs/SDK come out.
The more interesting question is whether Adobe will update the Profile Editor. Now, a lot a people depend on the Profile Editor, but it's always been a beta release, not production software, and it's not been updated since it was introduced. So I'd not recommend holding your breath for an update.
UPDATE: The profile editor will be updated - see this post.
FURTHER UPDATE: dcpTool is now updated - see this post.0Add a comment
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Luminous Landscape have been testing the Sony NEX-7, and found that when using the NEX-7 with non-Sony lenses, it's "CornerFix To The Rescue" .0
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Looks like the "mainstream" photographic sites are finally starting to "get it" as regards ETTR. Ctein, one of the better knows columnists on The Online Photographer, has published 'Expose to the Right' is a Bunch of Bull.
Welcome to the new converts to the cause! Better late than never :)0Add a comment
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Here a short review of PhotoRaw: RAW Konverter fürs iPad
"With PhotoRaw I've now found one app that does the job satisfactorily.
The 7.49 EUR each for the app is absolutely value."
It's in German, but easy to translate and view via Google translate.0Add a comment
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Umm, yes, scary but true.
Michael Reichmann has a new article on ETTR. It's called Optimizing Exposure, and you can find it on the Luminous Landscape site. The article itself doesn't have anything new - it's just a rehash of Michael's old arguments, "levels", etc, but it is vintage MR stuff, with references to important and highly competent people that Michael knows and that support what he's saying. Only he never actually mentions their names!!!
There's no point in my going over the ETTR stuff again - those who want a point-by-point commentary on what Michael wrote can look in the LL forum discussion of the article - other have already pointed out all the issues.
But two interesting things did come out of the article. Firstly, Michael makes the point that exposure on modern DSLR's in actually pretty primitive. Divorced from all the ETTR mumbo-jumbo, it's a valid point, and worth taking a look at the article for.
The second thing of interest that came out was an additional potential reason for using ETTR.
Quick recap - in my previous ETTR posts, I showed that ETTR was mostly a waste of time except in very particular circumstances - e.g., to effectively synthesize a lower ISO than your camera comes equipped with.
However, some of the folks in the forum pointed to an article by Emil Martinec of the University of Chicago, "The Consequences of Noise". It's fairly technical, and quite theoretical, but here's a short summary as it applies to ETTR:
Firstly, Emil destroys Michael Michael Reichmann's "levels" argument for ETTR. This is what he says:
"In particular, the idea that the benefit of ETTR comes from the "number of available levels" suggests that the image quality would be one stop worse for the ISO 1600 image than it is for the ISO 3200 image, since by being one stop down from the right edge of the histogram, fully half the available levels are not being used. However, as we have seen, noise is much more than two levels in all exposure zones at these ISO's, so the extra levels used in the ISO 3200 image simply go into digitizing the noise, and are thus of no benefit in improving image quality. In fact, the quality of the two images will be very nearly the same (rather than one stop different)"
Sound familiar? It's the same answer I came to previously.
But then Emil goes on to make the point that that noise in a digital image actually comes from more than just the sensor, it also comes from the electronics around it (the amplifiers, etc). This is known as "read noise". In a modern camera, generally the read noise is quite low, and you're only really worried about the sensor noise. But Emil's argument is that you can minimize the read noise by shooting at higher ISO. Specifically he says that:
"Somewhat counter-intuitively, for fixed aperture/shutter speed, it is best to use the highest possible ISO"
Now that might sound somewhat crazy when you hear it the first time. But think of it this way:
- Sensor noise is basically fixed for any combination of aperture and shutter speed (the point I made in the previous posts on ETTR, and the reason why you should just adjust ISO, not mess with ETTR). If the same number of photons hit the sensor in the same time, you're going to have the same sensor noise.
- However, because of the gain of the amplifiers in the electronics, effective read noise (the noise from the electronics) is lower at high ISO.
So there you have it - there is another situation in which ETTR will benefit you in addition to the ones I laid out in the previous posts. That situation is the one in which the read noise (the noise from the camera electronics rather than the sensor) is a significant portion of the image noise.
The question, of course, is does that happen in practice? ETTR has a number of downsides, such as the color shifts I showed previously, so you won't want to use ETTR unless there's a real advantage.
The answer to that question unfortunately depends on your camera. Personally, I've never seen a practical shooting situation with a modern camera where read noise was an issue relative to sensor noise. But I can't rule out it happening.
LATE EDIT: So, ok, here's the proof - as predicted by the theory above - courtesy of Guillermo Luijk. For some cameras, going to higher ISO really can reduce noise for the same shutter speed/aperture. However, note that it took four stops of overexposure (ISO 100 to ISO 1600) on an old Canon 350D to get Guillermo's results, and Guillermo specifically says that many cameras don't do this at all. Interesting, but in my view, four stops is a bit impractical.
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For those planning to be on the bleeding edge and upgrading to OS X 10.7 Lion, please be aware that there is a new version of CornerFix, version 1.4.2.0, available. Earlier versions may crash with Lion.
You can update now - the new version is compatible with all version of OS X from 10.4 onwards.
There are also two other upgrades (which apply to the Windows version as well):
- Fix for an issue that could result in Lightroom displaying an out-of-date thumbnail if the image had been loaded into Lightroom before processing with CornerFix;
- Lens detection for the new Leica lenses.
You can download from the usual place.
Enjoy.
Sandy0Add a comment
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.....and, not of course that I would say "I told you so", but well, I told you so. As predicted in this post (yes, all the way back in Feb 2010), Leica have managed to significantly improve "red edge"/"Italian flag syndrome", but not completely eliminate it in all cases, even for modern Leica lenses. Take a look at the various posts on the Leica User Forum for the details.
On predictions, a second prediction I made at the time has also turned out - take a look at this interview with Dr. Andreas Kaufmann. "Q: Which is the best performing Leica product line? Dr.Kaufmann: Definitely the M9."
Unfortunately, the jury is still out on third prediction I made at the time - that the Leica S2, while a fine camera, would be a financial bust for Leica. As it turns out, I was at least partially right - the S2 hasn't significantly penetrated the pro market. However, I'm told that it has racked up significant sales in the amateur market. Given the price of the S2 and a lens or two, that tells you something about how much some amateurs have to spend on their hobby. Are those sales significant enough to pay for the program? Well, we'll find out eventually.0Add a comment
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Photoshop Touch is Adobe's latest addition to Photoshop's capabilities - basically, it adds one-touch image transfer from an iPhone or iPad to Photoshop. You can read about it on this page.0
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Rob Galbraith has a good comparison of the various raw processing apps for the iPhone and iPad (including PhotoRaw) in his article on the iPad 2.
Specifically, he lays out the trade-offs between PhotoRaw and the other guys - which is that PhotRaw takes a long time to import images because it does as much as possible up front, but then provides real-time adjustments to exposure, etc, whereas the other guys import faster, but then don't allow real-time adjustments. First time I've seen a clear discussion of the differences.
Update Dec 2011 - Note that while Rob's article is still interesting, the version of PhotoRaw now available has come a LONG way since Rob wrote his review, addressing several of his concerns such as white balance adjustments, etc. Best thing to do is to try the free version PhotoRaw, PhotoRaw Lite.0Add a comment
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