Monthly Archives: March 2012

ACR lens profiles

Lightroom, Nikon lenses

Fixing what ails fine optics.

Adobe has long provided a free utility named Adobe Lens Profile Creator which permits any user to generate lens profiles which will correct the three most common causes of image degradation – vignetting, chromatic aberration and distortion. These profiles work with Lightroom 3 or later and with Photoshop CS4 or later.

The instructions are generally good, and the learning curve is steep, whereafter the process is easy and fast. A provided checkered target is snapped nine times – four at each corner of the frame, four at the center of each side and one in the center. The nine files are then input to the application and a profile is created. Multiple profiles for a lens, created at different focal lengths (for zooms) and apertures can be consolidated in one profile file, with PS or LR automatically choosing the profile nearest to the lens settings used. To create a file for RAW originals you need to use DNG files for the application – good luck finding that clear statement in the instructions. The key to all this is that the illumination on the target must be perfectly even. Any shadows will be interpreted by the application as vignetting and erroneous correction will result in the profile thus created.

Once you get the hang of it you can produce an accurate tailored profile, from taking the snaps to dropping the profile file in the right directory, in 10-15 minutes. The first one takes ages, of course.

Many profiles for modern lenses, created by Adobe, are included with Lightroom and Photoshop, mostly for the G and a few late D lenses, but aficionados of the older manual focus Nikkors and many AF D lenses are out of luck. Users of PS CS5 can access user created profiles, but I suggest you read the caution at the end of this piece before jumping in.

I set to making profiles for the two lenses in my collection most in need of them – the 20mm f/3.5 Ai-S (same optics as the Ai version) and the 35-70mm AF D f/2.8 zoom (same optics as the earlier ‘non-D’ variant). Longer lenses seldom need much in the way of correction. Profiles seem to benefit wide angles and wide zooms most. No surprise there as that’s where it’s hardest to fight the laws of physics – distortion and vignetting being much in the picture, if you get my drift.

The profiles below only work with RAW and DNG files. If you use TIFF or JPG they will not appear in LR or PS. They work equally well with full frame and APS-C sensors, as both LR and PS compensate appropriately. They are most effective in full frame Nikons, where the peripheries of the lens’s image circle are most used.

20mm f/3.5 profile:

For the 20mm I created profiles at f/3.5 and f/8. f/8 is very much the sweet spot for this fine optic and use with a tailored profile really makes the results sing.

Click to download the profiles for the 20mm f/3.5.

Even though the 20mm f/3.5 Ai-S lens has no CPU, as long as you remember to dial in the 20mm ‘non-CPU’ lens setting on the camera, the profile will be automatically recognized from the related EXIF data. This should apply to any lens which does not post EXIF focal length data to the file. LR and PS depend on this information to look up the right lens automatically, though you can always override the applications’ choice.

35-70mm f/2.8 profile:

For the 35-70mm zoom I made profiles at f/2.8 and f/5.6 at each of 35mm, 52mm and 70mm. This lens trends, like many zooms, from barrel distortion at the wide end to pincushion distortion at the long end. Vignetting at f/2.8 is largely gone by f/5.6.

Click to download the profiles for the 35-70mm AFD zoom.

Once downloaded, place these files in this directory:

Replace ‘ThomasMBA’ with your user name. In Lion, hold the Alt key in Finder->Go to see your user Library.

When you restart Lightroom 4 (or 3) you will see this in the Develop module once you check the ‘Enable Profile Corrections’ box for a RAW snap taken on the 35-70mm AF D zoom, as an example:


The profiles for the 35-70mm in Lightroom.

Even though I have created six profiles for the 35-70mm AF D zoom, at 35, 52 and 70mm and at f/2.8 and f/5.6, you only see a choice of one file. Lightroom will automatically choose the profile closest to the focal length and aperture you used – no need to select from multiple profiles.

Here’s the 35-70mm profile at work at 70mm and f/2.8.

Before:

No profile applied.

After:

With profile applied. Vignetting is gone as is the slight pincushion distortion.
In this image, the centers of the long and short sides have been bowed out
and the corner vignetting has been removed by the lens profile.

The changes with the 20mm f/3.5 Ai/Ai-S lens are much more noticeable, with fairly strong vignetting at f/3.5 removed and the ‘Cupid’s Bow’ wave like distortion of straight lines parallel to the edges of the image corrected. The latter cannot be properly corrected by normal manual distortion correction controls in LR or PS – only a tailored lens profile like the one above can do that. An already good wide angle lens is made great with this technique. The reason I have included two profiles in the file is that at f/3.5 vignetting is more severe than at f/8, whereas distortion remains unchanged. Lightroom will automatically choose the profile closest to the focal length and aperture you used – no need to select from multiple profiles, though the profile file actually contains two profiles.

Both profiles included in the downloadable file fail to correct very minor chromatic aberration (color fringing) but a click on the ‘Remove Chromatic Aberration’ box in LR4 corrects that perfectly, looking at 30x screen enlargements of ultra high contrast subjects. The one click approach compared to the sliders in LR3 sounds simplistic but in practice works superbly.

Before:

20mm f/3.5 Nikkor at f/3.5. No profile applied.

After:

20mm f/3.5 Nikkor at f/3.5. With profile. Note the dramatic reduction in vignetting.

Well done, Adobe. And thank you Nikon for a real corker of a lens, fully usable at f/3.5 and outstanding at f/8. I look forward to publishing some snaps from this lens soon.

Enjoy!

A caution about Adobe’s lens profile database:

Go to PS CS5, load a RAW file and invoke Filters->Lens Correction. You will see a host of lens profiles, none authored by Adobe – they do not come with LR4 which contains all Adobe’s profiles as well as those submitted by lens makers like Sigma. (For reasons known only to the people at ADBE, you cannot download other lens’ profiles using LR4). Nikon and Canon do not submit profiles as that would cannibalize their RAW processing apps for the three people on earth who actually use them.

The problem is that these profiles, which appear to have been submitted by photographers, seem totally uncurated. As an example there are no fewer than 6 profiles for the Nikon 35-70 f/2.8 lens and each yields markedly different results. The descriptions all say “Nikon 35-70mm f/2.8 (raw)”. There is no indication of which aperture or focal length they apply to, making them completely useless. One Nikon profile is even listed as 0.0mm f/0.0, indicating the author failed to read the instructions. Why this is even in the database mystifies me.

My profiles are carefully made and accurate. It’s your choice.

Another Adobe cock-up:

LR4 comes with Adobe Camera Raw 7.0. On the PS side you can only get that with CS6 Beta. The latest version for CS5 is ACR 6.7 but the download will not install, has no instructions on installation, and the current 6.6.x will not convert LR4’s Process 2012 RAW files. I have read that 6.7 does not either, but obviously I cannot test that as the installer is faulty.

The workaround is to use LR4 as your first point of entry and RAW converter even if you propose sticking with CS5 for processing.This works for all but devotees of CS5’s ACR.

Simply round trip the file from LR4 to CS5/ACR whatever version (you will not be using CS’s ACR), using a lossless TIFF or PSD file format. This way, when Adobe tries to extort money from you when CS6 comes out at $600 or more, you can tell them where to stick it. You can bet they will be forced to keep the RAW converter database in LR4 current, or risk the wrath of a huge installed user base which does not want to spend $600+ on CS6 for occasional use. Hoist by their own petard.

I see no difference in the rendering of Process 2012 RAW files comparing a RAW in LR4 with a TIFF in CS5. The only difference is that the latter is four to five times the size, but $600 buys you a lot of storage ….

More profiles:

To see all the profiles I have created, click here.

The Lightroom 4 book by Martin Evening

Lightroom

Just buy it.

While there is a case to be made for non-photographers testing new hardware – after all you don’t have to be Annie Liebovitz to stick a camera on a tripod and shoot a test chart – no such argument can be sustained when it comes to writing software instruction books.

The hardware case is exemplified by sites like DPReview. Many do a good job of explaining and comparing features and performance, while attended by the worst photography on the planet. None of this is helped by a commentariat frequently focused on flame wars over brand X versus brand Y. But, as long as you stay away from the noise passing as commentary, sites like DPR add value to the hardware decision.

On the software front you have many poseurs passing as experts with one common attribute. That is, they seem to be software gurus who grew up with Photoshop and think that their familiarity with the arcana of vector based rendering makes them Cartier-Bresson’s peer.

That is why it is so easy to recommend Martin Evening’s latest Lightroom book, which addresses Lightroom 4. He is a working professional photographer, a good one at that, writes clearly and illustrates his recommendations thoroughly. I have previously bought his LR v2 and v3 and PS CS5 books, and recommend the latest unreservedly. The section on the use of the new enhanced localized adjustment tools alone is worth the price. Mine ran me $30 at Amazon US.

Having bought v2 in paperback and v3 in the Kindle version for the iPad, I find I much prefer the paperback for ease of cross reference and quick access to features I need to understand. At least I don’t have to recycle v3 – the Delete button being all that is needed.

White Birches

Photographs, Short stories

From my favorite place in Yosemite Valley.

Ansel and I had been taking pictures together in Yosemite for several years, but eventually I tired of the genre. I was at a point in life where never seeing another image of Yosemite would leave me a happy man. Ansel would keep dragging me to El Capitan or Bridalveil Fall in the most godawful weather, and just stand there goggling, lumberjack shirt, pot belly and suspenders. Every now and then he would mutter “Far out, man” in between hits on that little hash pipe he carried everywhere. The strange thing was that, even though he was carrying a load of gear, he never actually took any pictures. On the rare occasions he straightened up, he would repair to that smelly darkroom in the log cabin and make more prints from snaps he had made in the same locations decades earlier. As long as I knew him, he photographed nowhere else, ever since he got that suspended sentence for driving with a kilo in the trunk. Only his fame had kept him out of Alcatraz.

“What gives, Ansel?” I asked, as he staggered out of a darkroom by now blue with marijuana fumes. “Far out, man, but you know ….” and here he paused to take another deep hit from that bong he had hand carved in the shape of Half Dome “…. all they want is prints of the old ones even though my gear was crap back then, ’cause I mostly tried to make a living as a barroom pianist and that barely kept me in bread, water and pot, certainly not in the best photo gear. But look, I get $2,500 for these, $3,500 if I yellow them up a bit and make sure to mark them ‘Limited edition 1/5’. I suspect I’ve unloaded about two thousand or so of that limited edition over the years. Hey, man, it’s a living. Gee, this is good stuff. Wanna hit?”.

Ansel dropped by the other day, zonked out of his gourd as usual, clutching a bunch of prints he had just made of those damned white Yosemite birches. When will photographers stop milking this theme? I mean, come on, how many more times in your life do you want to see a snap of a bunch of spindly, butt ugly, emaciated white trees with peeling bark, over printed and over enlarged which some jerk weed has just used $50,000 of gear to replicate for the umpteenth time?

He offered me a toke but I politely declined, seeing as it’s not my thing.

“But I’ll tell you what, Ansel. How about I give you one of my personally autographed white birches? In full color, as that’s not really something you know how to do now, is it? Feel free to stick it any place you like”.

“Far out, man. Like, yeah dude. Birches rock. I’m getting $5,000 for mine now!”

So that’s how Ansel happened to end up with one of my Yosemite snaps on the wall of his rustic cabin. I told the old fart it was hand printed from my 8″ x 10″ Deardorff, made using old growth oaks from Yosemite, and he bought it. And I think he missed the door handle, being higher than a kite at the time. He told me, in the strictest confidence, that he had to augument his energy with a couple of uppers, while in the darkroom, as he was so sick and tired of printing the same images for well over four decades now.

“That’s awesome dude. All my gear is handcrafted by that dude I get messed up with down the valley. Trouble is, he always promises to finish in a month, then when I go to pick the gear up, find he’s forgotten to start, because he was too out of his mind to do anything. My last tripod took him five years to make – said he finally got on with it as he was out and needed the money for a new stash. I was gonna offer him some of mine but reckoned that would add another year to the wait”.

White birches. Off New Montgomery Street, Yosemite. D700, 35-70 AF D.

New balls for the iPad

iPad

Strange but (mostly) effective.

I intensely dislike using a case with the iPad. It argues with the functionality of the device and can double the weight. You might as well carry a laptop.

However, I continue to insist on dropping my iPad whenever the occasion presents itself and my iPad 1 is off for a replacement back right now, all four corners badly bruised. One is so bad that the glass is sticking out and the rubber gasket is beginning to pull out. Concrete and iPads are not the best of friends.

The alternative is some sort of corner protection, as the iPad will insist on landing on a corner much as a piece of bread with marmalade will always land sticky side down, and statistical analysis be damned. We are talking Murphy’s Law here, not statistics. So I hunted around for stick-on corner rubber protectors and drew a blank.

The closest I could come is the unfortunately named iBallz, which place a hard rubber ball at each corner, held together with an ugly and dysfunctional looking elastic cord.

Bert with iBallz installed. On the iPad, that is.

Let’s get to the drawbacks first (an * indicates a fix or workaround exists):

  • The whole becomes bulkier.
  • The string and related lock are butt ugly and uncomfortable regardless of how placed.*
  • The on-off switch at top right can only be worked with a fingernail on the left hand.*
  • The rear facing camera is partly obscured.*
  • The power cable port is a litttle trickier to access owing to the intrusive presence of the elastic cord.*
  • Some 30% of the speaker grille at the lower left rear is obscured.*
  • The headphone socket at top left is completely obscured.*
  • The SIM card slot at the right (on iPads with 3G or 4G) is blocked.

Stated differently, the makers need to get off their rear ends and redesign these things to address the above issues, a trivial process. Don’t hold your breath, though – these problems apply equally to iPad 2 and iPad 1, though the latter has no camera to be obscured. It’s not like they haven’t had eons to fix the design errors. The complacency of the manufacturer is not a prescription for its survival.

Just about everything that is wrong with iBallz, here on iPad 3.
Arrow denotes almost buried on-off switch. Also note the partly obscured camera lens.

The redeeming qualities are significant, however. The balls – some sort of hard, matte plastic – are very light. They fit the corners on my iPad 3 tightly. And, most importantly, they provide real protection. I have not had the courage to drop test this on the driveway; be patient, Mother Nature will doubtless provide the data sooner rather than later. Place the iPad down on a flat surface and neither glass or back will touch anything. Further, the balls provide a surprisingly comfortable hold when using the iPad on your lap, meaningfully superior to using it without the balls. In fact, I would miss them were they to be removed. The elastic cord can be pulled pretty tight and lifting the iPad by it causes no concerns, but it remains ugly and out of keeping with the iPad’s design. With the balls fitted it is much easier to lift the iPad from a flat surface with one hand owing to the stand-off, otherwise a risk-fraught exercise made more so by the bevelled edges on iPad 2 and 3. iPad 1 is far superior in this regard. Even with the cord removed, picking up the iPad with just one hand is night-and-day better.

Solutions to the bad stuff: I have cut off the elastic cord, as it’s an awful kluge. They should have dispensed with the sliding lock and simply have spec’d the length of an endless cord correctly, redesigning the balls to bring the cord far closer to the edges of the iPad. I placed a dab of glue on each corner on the back of the iPad to install the balls, using a glue whose residue is easily removed when the date of sale comes.

I have also relieved the top right ball with a Dremel tool to restore the camera function, and to make the on-off switch more accessible. This one has to be glued very carefully as you do not want glue on the camera lens (unless you like Holga-quality images) or on the on-off switch.

The relatively large relief for the camera’s lens is dictated by its wide angle of view.
The on-off switch no longer needs a fingerail to operate. Fit remains tight.

Though the top left ball obscures the headphone socket, I’ll leave that alone as I use wireless, Bluetooth headphones. I’ll leave the lower left ball, the one which obscures the iPad’s speaker grille, unchanged, as that speaker is poor in any case. Headphones are the way to go for quality sound. The obstruction of the SIM card slot is a non issue for me as I do not change SIM cards.

Too bad the balls aren’t even smaller, but it’s a start. The maker claims these fit all three iPad generations. So far I have only tried them on iPad 3. The profile of the slot is clearly intended for the squarer iPad 1, another indicator of the maker’s sloth in not redesigning this for iPad 2 and 3 with their tapered edges. Mine ran $25 from Amazon and alternative colors are available, including pink for the girlie set.

Insurance: This is another alternative, and a costly one. Reckon on $100 for two years of drop, failure and theft coverage. There are two more drawbacks, over and above the cost. One is that the iPad is gone when out for repair – that’s an awful thought. The other is that insurers get rich by not paying claims, so good luck in recovering. The integrity of that business makes the people at the Vampire Squid seem short-listed for canonization, by comparison.

Conclusion: A poorly thought out, poorly engineered, sloppy product which needs a bit of work to make it decent looking and practical. Way overpriced at $25, shipped, but I can’t find an alternative for the $5 this is worth.

A disgusted Bert models the final thing. The Mickey Mouse iPad.

As for screen protectors, save your money. After two years of brutalizing iPad 1 with no case or screen protector, often as not tossed in a bag, the screen remains perfect and with not a scratch in sight. A screen protector, like the Zagg is not only a complete waste of money, the wonderful definition of the iPad 3’s screen will not benefit and chances are you will get bubbles when you install it. Like running a Ferrari on diesel.