Mark II Artist’s Viewfinder 3.1 Update

February 10, 2014 by

IMG_6679The 3.1 update of the Mark II went online during the weekend. There are three groups of new features: wide converter support, device support, and new cameras/backs.

The following is an excerpt from the press release.

—

New features:

  • Supports the iPad mini with Retina display.

Added wide converter support:

  • olloclip 4-in-1 Wide on iPhone 4, 4s, 5, 5s and on the 5th generation iPod touch.
  • Schneider iPro Series 2 Super Wide on iPhone 4, 4s, 5.
  • Schneider iPro Series 2 Wide on iPhone 4, 4s, 5.

Added cameras:

  • Arca-Swiss F-classic 4×5, F-classic 5×7, F-classic 6×9, F-classic 8×10, F-metric 4×5, F-metric 5×7, F-metric 6×9, F-metric 8×10, M-Line two mf, M-monolith 4×5, M-monolith 5×7, M-monolith 6×9, M-monolith 8×10, misura 4×5, misura 8×10, Rl3d, Rm2d, Rm3d factum, Rm3di.
  • ARRI ALEXA XT, ALEXA XT M, ALEXA XT Plus, ALEXA XT Studio.
  • Blackmagic Cinema Camera MFT, Pocket Cinema Camera, Production Camera 4K.
  • Canon EOS 70D, 100D/Rebel SL1, 700D/Rebel T5i.
  • Fujifilm X100S, X-A1, X-E2, X-M1, X-T1.
  • Linhof Kardan re, M 679cs, Master Technika 3000, Master Technika classic, Technikardan S 23, Technikardan S 45, Techno, Technorama 612 pc II, Technorama 617s III.
  • Mamiya 6, 6 MF, 645DF+.
  • Nikon AW1, D610, D3300, D5300, D7100, Df, J3, S1.
  • Olympus OM-D E-M1, OM-D E-M10, PEN EP-5.
  • Panasonic DMC-G6, DMC-GF6, DMC-GM1, DMC-GX7.
  • Pentax K-3, K-50, K-500.
  • Samsung GNX, NX-30, NX-300, NX-1100, NX-2000.
  • Sigma DP3 Merrill.
  • Sony A3000, A5000, A7, A7R, NEX-3N, NEX-5T, PMW-F5, PMW-F55, SLT-A58.

Added backs:

  • Phase One IQ250, IQ260, IQ260 Achromatic, IQ280.

—

One thing to note is that the Schneider wides are not supported on the iPhone 5s yet. The reason is simple: Schneider have a new case for the iPhone 5s that we were unable to buy anywhere.

The Mark II supports only certified converters, so if you find your favorite converter missing, please let us know.

IMG_2030Do you like this app?

There’s also a small new feature that we do not advertise in the press release: you can easily share your love towards the app.

Open the menu, scroll all the way down and tap I Like This App!

It doesn’t cost you a dime, but spreading the word helps us to bring exciting new features to the app faster.

Thank you for letting your friends – and even complete strangers – know about the Mark II!

But please do not use reviews as a feedback or bug reporting channel! It’s not bi-directional and we can’t get in touch with reviewers.

Use Report a Problem in the menu instead. It’s the fastest way to get in touch with us – and you are not required to have an actual problem to use this feature.

Filed Under: My Apps, Photo Software Tagged With: , ,

Fixing the Blank Image Bug in WordPress

January 26, 2014 by

A recent update to this site brought a nasty bug: social networks displayed a blank image next to posts not containing any image. It was a bit tedious to manually remove them (and they can’t be removed in Flipboard).

The bug was introduced when I updated the JetPack plugin from 2.5 (if memory serves) to the latest 2.7. In a rather stupid move this version puts an og:image Open Graph tag pointing to a blank image if the post doesn’t contain one. Digging around the ‘net showed that this issue was present in 2.6 and that the folks at JetPack think that it’s good this way. Well… Leaving the offending tag’s removal the only possible way to fix it.

Fortunately this is pretty simple: add the following code to the end of the theme’s functions.php file. It will remove the og:image tag when JetPack sets the default blank image.

The code snippet fixes another issue: JetPack sets the twitter:site tag to their own Twitter account – another no-no. Just don’t forget to replace my Twitter with yours :)

function fix_jp_og_bugs ($og_tags)
{
    $og_tags['twitter:site'] = '@laszlop';

    if  (0 == strcmp ($og_tags['og:image'],
        "http://wordpress.com/i/blank.jpg")
    {
        unset ($og_tags['og:image']);
    }

    return $og_tags;
}

add_filter ('jetpack_open_graph_tags', 'fix_jp_og_bugs', 11);
Filed Under: Code Snippets Tagged With: , ,

Thoughts on iDevice Wide Converters

January 20, 2014 by

Last week I added support for a bunch of iPhone/iPod wide converter lenses to the upcoming release of our Mark II Artist’s Viewfinder app. They were Schneider’s Series 2 super wide and wide iPro lenses as well as the wide lens in olloclip’s 4-in-1 offering. The picture below shows them: Schneiders on the left, olloclips on the right, and the ALPA ACAM in the middle. They are shown without their mounting cases (except for the olloclips).

A bunch of wide converters

A bunch of wide converters

While they are all suitable for viewfinder use, you can’t expect good optical performance from such lenses, period. Their manufacturers like to advertise them as “high quality”, “precision”, etc. Well, they might be high quality for someone who lo-fi filters the crap out of their smartphone images, but in my book they are not usable for real photography – even on smartphones.

They are all priced in the same range ($65-$100) with mounting hardware included. Schneiders usually occupying the higher end of this range.

Conversion factor and distortion

The bad news: advertised conversion factors can’t be used to compare these lenses. All super wide converters we measured exhibit huge (10% or more) barrel distortion. What gets in the marketing material is the magnification ratio with no distortion correction applied. That is, they count in the extreme edges, which will result in smaller factors.

But when distortion is removed, those extreme edges go away (as you can see in the first illustration in my previous post). The result: Schneider’s super wide lens that’s advertised as having a 0.45x conversion factor is a 0.5x lens is reality. ALPA’s lens, which is advertised as 0.5x (because I told them to) is a bit wider in reality than Schneider’s 0.45x.

The conversion factor also changes from device to device – and all the adapters I measured go wider when they are used on a device having a wider native field of view. For example, the ALPA is a 0.5x on an iPhone 4, but a 0.48x on an iPhone 5S.

ALPA ACAM mounted for measurement

ALPA ACAM mounted for measurement

If you look at conversion factors you’ll find out that there are two distinct classes: 0.5x and 0.65x. The Schneider super wide and the ALPA wide belongs to the first, and the Schneider wide and the olloclip belongs to the second. Is it important to note that the wide Schneider exhibits only a small amount of barrel distortion – and this lens would be usable even without correction. The olloclip is not, it has the same huge distortion as super-wides.

Sharpness

The sharpest is the Schneider super wide. The least sharp is the iPhone 4/4S variant of the olloclip – so much that I struggled for hours to find the checkerboard corners in the sea of blur and chromatic aberration.

Other aberrations

Schneiders are almost free of chromatic aberration. All others exhibit a huge amount of it in the corners. Centering is bad on all converters. The Schneider super wide also exhibits hard to correct mustache-like distortion. On the iPhone 5 for example this – together with bad centering – causes residual pincushion distortion on one side of the image after the barrel has been removed.

Mounting

Olloclips tend to slip off easily – except when you use it on an iPod, where a rubber inserts keeps the lens in place. Converters with cases are all solid, although I found Schneider’s iPhone 4/4S case too tight and hard to remove.

Mounting on the top of the camera (in the hot shoe for example) is another story. If you want to use the converter lens to compose stitched panoramas with the Mark II, you’ll need a holder that keeps the phone’s lens centered with the camera’s. This is to avoid parallax as much as possible. This is where things start to cost more. ALPA makes a holder that ships with the super wide converter lens and two cases. Other manufacturers, such as Cambo, also make holders (the Cambo includes a converter lens that the Mark II does not support yet). But be prepared to spend $800-$900 on these.

My favorites

I’m not a big fan of the Schneiders. I was confused about which case is compatible with which series lenses, and their site offers little help. Now I know that the series 1 cases can hold series 2 lenses, but not vice versa.

Actually I have two favorites. The ALPA rig (holder and such) is what I use. It offers the widest view, it’s easy to mount on my camera, has the sturdiest lens mount, and so on. All in all, highly recommended.

The other, the olloclip 4-in-1 on an iPod touch 5, was a surprise for me. I never thought how usable this combo could be. It’s lightweight, fast, and the rubber insert keeps the lens from falling. It can simulate lenses down to about 24mm (on full frame 35mm cameras). Not to mention that it’s the cheapest way to get into the wide converter world of the Mark II.

Filed Under: Photo Equipment Tagged With: , , , , , ,

Christmas Catch

December 24, 2013 by

I photographed a kingfisher family just a few days before Christmas. Despite the bitter cold and the flat light, it was a great day, resulting in lots of images.

Christmas Catch

Christmas Catch

Happy holidays to you and your loved ones!

Filed Under: My Photos Tagged With: , ,

Mark II Artist’s Viewfinder Released

December 14, 2013 by

avf2iconI have been silent for the last weeks for a reason: we were working hard to bring the Mark II Artist’s Viewfinder out.

And now I can proudly announce that a few minutes ago it went online on the App Store, so you can go and grab it. :)

The usual announcement stuff will come next week, but you can find most of the info on the app’s microsite right now.

One more thing…

Courtesy of ALPA of Switzerland, the eFinder Tools are now part of the Mark II – no additional in-app purchase necessary. Although the parallax/shift tool is still supports ALPA cameras only, you can freely use the super precise (1/10 of a degree) 3D level with any camera. I might be biased, but for me it leaves the 5D Mark III’s two-axis level in the dust.

Filed Under: My Apps, Photo Software Tagged With: ,

Wide Converters in Mark II Artist’s Viewfinder

November 20, 2013 by

Today we announced the beta of Mark II Artist’s Viewfinder. With the Mark II we took a new direction on how we handle wide converter lenses. In the past we just multiplied frame line positions with the wide conversion factor, not doing anything about the optical aberrations of the converter lenses. And believe me, they have many. Distortion, chromatic aberration, centering errors, you name it, the converter has it.

Most of these aberrations can be safely ignored as nobody takes real images with a viewfinder. One of them however, distortion to be exact, is a huge problem. It enlarges the center portion of the image and compresses the edges, making the effort of precise frame line positioning futile.

Given the immense power of today’s iPhone GPUs, we set out to get rid of wide converter distortion forever. And I’m pleased to tell you that we succeeded: the Mark II sports real-time distortion correction! Following is an example of its power.

Before and after distortion correction

Before and after distortion correction

ALPA’s ACAM Super Wide Converter exhibits about 11% barrel distortion (on the left). Which is completely eliminated in the Mark II (on the right). Yes, resolution suffers, but it is pretty much enough for viewfinder use. There’s also some darkening on the lower left corner (the converter vignettes heavily and asymmetrically on the iPhone 5s – which isn’t a big issue after the correction).

With the corrected view we can simulate super-wide lenses, which is a blessing for landscape and architecture photography. But I also regularly use the ALPA’s iPhone Holder together with the ACAM SWC as a viewfinder for my Canon TS-E 24 pano stitches. Here’s a screenshot I took on my old iPhone 4 while composing The Circle.

IMG_1631

Composing a stitched pano

Note that the iPhone 4 isn’t fast enough to do the correction at full Retina resolution – all other supported iPhones (4S/5/5S) are.

At launch we’ll support ALPA’s ACAM SWC, but the lab and the measurement technology is ready, and we’ll add adapter/device combinations as we measure them. On the device front, iPhone 4/4S/5/5S are supported.

So if you regularly shoot wide, or want to get a tool that allows you to visualize tilt/shift stitches, then head to the Mark II’s site and sign up for a beta. Seating is limited, so hurry! Then it’s time to order an ACAM SWC from ALPA.

Filed Under: My Apps, Photo Equipment, Photo Software Tagged With: , , , , ,
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