So here's where I came from and where I'm at now - getting into m4/3.

For those who've read my prior posts, you don't need any initial intro info, but for anyone who hasn't seen my prior posts, I included intro info of what I'm about.

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I'm an old pro photographer who used film for years, then adapted to DSLR full frame digital, then later adapted to DSLR APS-C, and now working on adapting to m4/3. I'm doing this so I can have lighter gear as I'm getting older. I do a lot of photography of real estate interiors.

I'm not striving for perfection. I'm striving for a high level of adequacy done fast in volume. Get in, get it done, get out. Move on to next job. I'm after the best results possible without using a tripod and without having to spend time post processing on a computer. My photos are used mostly online on websites at 1080 pixels wide, or sometimes printed 10" x approx 7.5" on 8.5" x 11" paper. So my resolution needs are modest. I always set my APS-C cameras on jpg small fine and still had to resize smaller for the Web (used Gimp for resizing).

For real estate interiors I look for ultra wide rectilinear (corrected, not fish eye) lenses with at least 90 degree horizontal FOV. Ideal is 95 to 100 degree horizontal FOV. I also look for (after camera correction) -0.7% distortion or less. Ideally -0.5% or less. Also, vignetting of -1.5 EV or less, but I prefer less than 1 EV if I can get it. Those are the ultra wide angle lens and camera combinations I look for so that I can do a good job in-camera and not have to spend extra (unpaid) hours on a computer. This formula worked well for me with DSLR full frame, and later with DSLR APS-C.

DSLR APS-C lenses have fallen slightly short of my ideal UWA lens standards, but have gotten me by, and I appreciated their smaller size and weight. Now it appears to me that Olympus OMD with Panasonic 7-14 F4 (and A2 rear filter) will get me by better than I used to do with DSLR APS-C due to great lens and great OMD bodies with lens corrections and great stabilization. I love the M10ii and M5ii ability to do keystone correction in camera. I bought an M10ii and M5ii.

For comparison purposes: Zeiss Distagon T 18mm f/3.5 ZF (FX) (a full frame lens for Nikon FX bodies) has -1.8% distortion, which does NOT impress me, especially for an expensive German lens.

The best ultra wide angle lens I've ever used was a Sigma 14mm F2.8 on a Canon full frame body. The Sigma 14mm F2.8 has only -0.6% distortion (without any camera correction). That's great for a 14mm lens with a 114 degree diagonal field of view. I'm not sure what it's horizontal FOV is, but I'd guess it's around 107 degrees horizontal FOV. It was an awesome lens.

The worst lens I ever used was a Sigma 8-16mm. I don't know the distortion figures for it, but it was awful. Images were so distorted that the pictures were unusable. I've never tried a Sigma 10-20mm, but I've read it's pretty good, especially the F3.5 version.

For ultra wide angle lens -0.5% distortion is excellent, IMO. -0.7% is good. -1% is marginally acceptable to me. More than 1% is unacceptable to me. IME, most people won't notice distortion until it gets worse than -0.6%, and it's not bothersome (to real estate people) until worse than -0.8%.

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The below lens performance figures are AFTER in-cameras corrections for jpg.

Note: I included Canon and Nikon DSLR APS-C ultra wide lenses for performance comparison to m4/3 lenses. The Canon and Nikon APS-C bodies have different size sensors with different crop factors. Canon at 11mm and Nikon at 12mm give approx the same 105 degrees diagonal FOV, which I'm guessing is approx 92.4 degrees horizontal FOV. I need a minimum of 90 degrees horizontal FOV. So 92 degrees is adequate, though more would be better.

Canon 10-18mm has -1.7% distortion at 11mm, and -1.5 EV. I'd have to use it at 11mm most of the time to get wide enough field of view. Note: I wouldn't use it at 10mm due to excessive distortion and vignetting. It's not usable quality until 11mm.

Nikkor 10-24mm has -1.8% distortion at 12mm, -0.97 EV. I'd have to use it at 12mm most of the time to get wide enough field of view. Note: I wouldn't use it at 10mm or 11mm due to excessive distortion. It's not usable quality until 12mm.

Panasonic 7-14mm F4 has -1.12 distortion at 7mm, vignetting -1.16 EV; Has approx -0.59 distortion at 8.5mm, vignetting -1.15; I'll be using it from 7mm to 8.5mm to get wide enough field of view. It's an excellent lens other than flare. I'll fix that by adding a Wratten 2A filter.

Olympus 7-14 F2.8 is to large and heavy. I'm not going to carry it. If I was willing to carry a beast like that I'd have stayed with full frame gear.

Olympus M.Zuiko Digital 9-18mm f/4-5.6 ED has -1.79% distortion at 9mm, vignetting -0.74% EV. I'd be using it at 9mm most of the time for real estate interiors. This lens does not meet my standards. The -1.79% distortion after in-camera correction is unacceptable. I don't want to spend computer time correcting distortion.

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The following lenses aren't anything I'd use for real estate interiors, but they do interest me for general photography. So I wanted to find out their distortion and vignetting.

Olympus M.Zuiko 17mm f/1.8 has -0.5% distortion, vignetting -1.1 EV

Olympus M.Zuiko 25mm f/1.8 has -0.5 distortion, vignetting -1 EV.

Panasonic Leica DG Summilux 25mm f/1.4 ASPH has -0.04 distortion, vignetting -0.55 EV. Wow! That's a nice lens, but larger than I want. I got the smaller (and good enough) Olympus 25mm F1.8.

Olympus M.Zuiko Digital 45mm f/1.8 has +0.66% distortion, vignetting -0.37 EV

Olympus M.Zuiko 14-42mm f/3.5-5.6 II R has -1.8% distortion at 14mm, vignetting -0.66 EV. At other focal lengths the distortion is very low, especially for a zoom lens. This is a good performing zoom lens.

Leica also makes a Panasonic 15mm F1.7 and maybe a 42mm or 45mm which are probably fantastic lenses. I didn't investigate these yet. Maybe later.

It's not AF (though do you really need it at 8.5mm?) and it's not really that small, but if it's low distortion you want, it's your guy:

http://www.photozone.de/m43/946-kowa85f28?start=1

you would need to use it with a 4/3 to m.4/3 adapter, but still a lightweight.

There is a detailed review of this lens here on DPR.

http://www.dpreview.com/reviews/olympus-9-18-4-5p6-o20/2

It seems to have low distortion, though I mainly used it for landscapes and never bothered to make any PP correction.

I don't shoot my 4/3 kit very often these days, but when I did the 9-14mm got a lot of use. No doubt when I get a m.4/3 body later this year the little 9-14mm will once again get lots of use

Peter

I was using mine in the garden yesterday.  It's very light.  IQ is acceptable, never checked distortion and vignetting.

Andrew

Jeff Tokayer wrote:

Oops, I meant 9-18mm.

Peter

I believe you should rethink your opposition to the Olympus 7-14 pro. It is heavy by m43 standards, much lighter than DSLR lenses. Darren Miles's review shows that the 7-14 is the correct lens for your needs.

https://www.youtube.com/watch?v=Qjdya4umwls

traveler_101 wrote:

I believe you should rethink your opposition to the Olympus 7-14 pro. It is heavy by m43 standards, much lighter than DSLR lenses. Darren Miles's review shows that the 7-14 is the correct lens for your needs.

https://www.youtube.com/watch?v=Qjdya4umwls

As far as being the correct lens for his needs, it seems he has done the math and already found the right one. Nice of you to tell him he is wrong though.  It is too big and heavy for me as well. The 7-14 2.8 pro might seem light to you but not to everyone. The whole point of this system is small and light and I much prefer Pannys aproach in this reguard.

Since you are happy to accept in-camera correction of distortion - since your distortion figures are from what I can see the post-in-camera figures - then I am surprised at your rejection of post-processing corrections on the computer. If you are using software such as Lightroom then its a trivial amount of time to apply corrections to batches of images in one go. You can even, for example, correct one image manually taken at say 8mm on a 7-14mm and then copy that correction to all other images taken with that lens at 8mm by using the metadata to select the target images.

If you use DxO Optics Pro to convert from raw, distortion from the 9-18 is totally invisible.  The correction is automatic for each body, lens, and focal length. Since I don't see how one can do much of anything with digital photography without using a computer, this is very easy post processing.  For me it is a no-brainer tradeoff for the $$ and pounds of big pro lenses.

Mike Ronesia wrote:

traveler_101 wrote:

I believe you should rethink your opposition to the Olympus 7-14 pro. It is heavy by m43 standards, much lighter than DSLR lenses. Darren Miles's review shows that the 7-14 is the correct lens for your needs.

https://www.youtube.com/watch?v=Qjdya4umwls

As far as being the correct lens for his needs, it seems he has done the math and already found the right one. Nice of you to tell him he is wrong though. It is too big and heavy for me as well. The 7-14 2.8 pro might seem light to you but not to everyone. The whole point of this system is small and light and I much prefer Pannys aproach in this reguard.

I asked him to RE-THINK.I did not tell him he was "wrong".

Looks like you've done a lot of research since your initial thread. Best of luck to you. Hope you enjoy working with your new gear.

FWIW the 15 1.7 and 42.5 1.7 are very nice lenses.  The other 45mm from Panasonic is a 2.8 macro and it is also a very nice lens.  If you yearn for the days of lugging weight, you could purchase the 42.5 1.2, but I think the 1.7 will probably be more pleasant to lug.

clemcam wrote:

If you use DxO Optics Pro to convert from raw, distortion from the 9-18 is totally invisible. The correction is automatic for each body, lens, and focal length. Since I don't see how one can do much of anything with digital photography without using a computer, this is very easy post processing. For me it is a no-brainer tradeoff for the $$ and pounds of big pro lenses.

I appreciate that software plays a part in m43 lenses however I was surprised just how bad the distortion levels on some of the lenses including the 7-14mm and 12-40mm so called PRO lenses, when compared to similarly wide lenses for larger format cameras.