This is one of those goofy photos you take when you want to check in on the performance of a new lens or camera. It's not going in the portfolio. Why did I take it? Because I wanted to see how a particular lens worked on a new-ish camera and with new lens profiles supplied with the upgrade to Lightroom 4.4.
I'll back up. I bought a Sigma 10 to 20mm f4.5-5.6 lens last year to use on an assignment photographing a new Whole Foods store. My primary camera at the time was a Sony a77 and while the 16-50mm lens was great for most stuff I wanted something with a bit wider angle of view. I researched the possible options and flipped a coin. The Sigma won. While the 16-50mm 2.8 DT lens was fully corrected for vignetting and geometric distortion by in camera profiles none were available either in the camera or in LR for the lens at that time. On the shots I took with the lens I added time to my post production routine to mess around with the edges and corners in DXO software. The results were fine for the project at hand. Not quite as good a performance as the 16-50mm but certainly very acceptable.
I was working in the latest ish of Lightroom a few days ago when I started looking to see if there were any new profiles for lenses I owned. I found profiles for the two Sigma/Nex lenses I recently bought, the 19mm and the 30mm. I kept looking and also found a profile for the Sigma 10-20mm.
I like the two primes and I was curious to see if the Sigma 10-20mm, when combined with the amazing sensor in the Nex-7 and supplemented with the correction in LR, would have much improved imaging characteristics over the uncorrected performance last summer on the a77 DSLT, fixed mirror camera.
This building, under construction, provided a nice range of lines and textures. I thought it would be a good test. I used the lens with an LA-EA1 adapter, which has no mirror, only contacts for electronic information and primitive AF. I decided to use manual focus and focus peaking instead.
The Nex-7 has a very high performance sensor with high sharpness. I'm very, very happy with the performance of the combined camera hardware and Lightroom corrections for this lens.
The image just above is of painted plywood barriers that surround the construction project. I thought it was a nice test of the lens's ability to render texture and a pleasing rendering of the saturated green paint.
As usual, performance parameters of modern cameras and lenses are moving targets which are influenced and changed by the influence of software driven corrections. It pays to check in frequently to see if some part of your imaging system has been improved and may provide increased performance metrics without having to upgrade.
Having done this test I'll be less reticent to use the combination for architectural projects in the future. Have I mentioned just how much I like the Sony Nex 7?
15 comments:
Why is Adobe so slow to in providing ยต43 lens profiles in Lightroom??
I'm using this same Sigma lens with my Pentax K-5. Didn't know that Adobe had made the profile available-- I'll have to check it out. Thanks for the heads up, Kirk.
With m43 cameras, the profile correction is already built in. That is part of the m43 system ethos that enables cameras and lenses to work between brands in the system. So, a panny lens on a panny m43 camera automatically corrects for distortion, CA etc. and that correction gets written to your RAW or JPG files. So you don't need separate profiles in Adobe.
I use the lens correction profiles & perspective adjustments in PTLens for almost all my wide angle stuff. For my particular lenses that has in the past got updated faster than the bigger more expensive more general purpose editors. And it doesn't let you make the pseudo "aesthetic" perspective adjustments that some editors allow -- it sticks to the solid maths of real perspective projection. Architects care about that. It turns the often iffy geometry at the edges of wide angle zooms into the tight linearity of the best tilt-shift primes, and then turns them into shift lenses.
I started with the Sigma 10-20mm which is pretty good as far as it goes. But once you correct the geometry the 10mm becomes 11mm. And you lose more width as soon as you do a perspective shift. So I moved on to the Sigma 8-16mm. A sharper lens which comfortably exceeds the magic barrier of a 90 degree view angle. The neat espresso of crop sensor UWAs :-)
So you can do lens geometry correction & some finical paralleling of verticals & still see all four walls of the room or quadrangle. Whereas you can't quite manage four walls even with the 10-20mm even with no editing & the camera rammed into a corner with a column tiltable tripod. Not that you're likely to want to do such a weird looking shot, just a handy illustration of the surprisingly significant difference between 8 & 10mm in linear projection wide angle lenses on crop sensor cameras.
Well ... if I understand well you like a lot your NEX 7.
But what about NEX 6 ?
Are you using it ?
Have you done any drooling over the specs on the upcoming (rumored) NEX7 ("R" or something after the "7")?
I thought that lens corrections are indeed applied in commercial raw converters with m43 cameras. It's part of the standard. If not, you'd see some serious distortion in many cases. If you use a non-compliant converter I think you get the distorted version. The whole idea of m43 is "see no evil" when it comes to lens corrections. The profiles don't show in the list because you aren't supposed to be able to turn off the corrections with m43. Now with regular 4/3, you just have to use Adobe's profile downloader and most of the problem lenses like the 12-60 have some workable profiles that users have shared.
I'm a big fan of the Nex 6 and use it a lot. The Nex6 is a great camera. The Nex 7 is a great camera with personality. Seriously though, I use the Nex7 for anything where I can get away with 50, 100, 200 ISO and I use the 6 for 400, 800 and 1600. Just an eccentricity since I know they are both nearly equal in low ISO at higher ISO's as per DXO.....That's a lot of "O's". I think if the 6 as a good automatic camera and shoot it in "A" mode. I think of the 7's as great manual cameras---love the two wheels.
When the bottom falls out of the Nex-7 market I'll buy a couple more. The "R" would have to offer something a lot better.
Can someone tell me what the LR Adobe profile correct for the Sigma 30mm?
Lightroom and ACR (and most other RAW converters) invisibly apply lens corrections to files from m43 cameras. For many of these lenses, the equivalent of a traditional rear element's final corrections is applied in software. Believe me, you would notice if the corrections weren't being applied. If you don't believe me, some Google searching will reveal the few RAW converters that don't apply the corrections, and you can compare for yourself.
I dunno, all the R would have to offer to convince me is the ISO standard hot-shoe from the 6...
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