Olympus Pen-F: analysis and hands-on

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Mine, my only, my preciousss!

Mine, my only, my preciousss!

There’s only one camera shop left in Perth and yesterday I was their first customer to buy the Olympus Pen-F. It’s not released on Amazon until Monday…

So it’s been the talk of the web. It’s undeniably a beautiful camera, with a rangefinder design reminiscent of its film camera predecessor of the same name. I’ve spent much of the last couple of days putting it through its paces.

I’m pleased to report it has a reasonable sturdy weight to it thanks to the aluminium/magnesium alloy shell. It feels just great in one’s hands. Well, my hands, anyway.

How does it perform?

First, software: it’ll be a little while before Adobe support it, but for us open-source fans, RawTherapee already supports the new .ORF RAW images in both 20-megapixel and hi-resolution 80-megapixel modes. (It seems to be the only open-source raw-converter to do so, at the time of writing.)

Second, I’ve been keeping dark-frame reference images for a few cameras, so I can compare its noise levels against predecessors and competitors. (Method: put the lens-cap on, place camera upside-down on desk, and then at every ISO from 6400 to 100 and below, at various shutter-speeds from 1/250s to 30s, take a couple of photos. A quick Python script reads the images, converts to greyscale and outputs various properties including the average lightness value per pixel.) Results aggregated by camera model and ISO with median-average.)

log-log plot of luminosity noise for various camera models by ISO

log-log plot of luminosity noise for various camera models by ISO

The graph shows 3 things, none surprising but pleasant to see confirmation:

  1. The Lumix GH2 really was awful for sensor quality. Its ISO160 is the Sony NEX-7’s ISO 800.
  2. There is a reasonable progression from Lumix GH2 to Sony NEX-7 to Olympus E-M1 and Pen-F; at native resolution, the E-M1 and Pen-F are much of a muchness for L-channel noise.
  3. The real game-changer is the high-resolution mode on the Pen-F – good, since this is one of the main reasons I bought the camera. This is to be expected: it uses the in-body stabilization to blend 8 images, four of them offset by 1 pixel (so it has full chroma bit-depth at every pixel) and four offset by half a pixel (so it has double the linear luminosity resolution). The result is about 1.5 stops better noise-performance.

Hi-res mode comes with a few limitations: the maximum ISO is 1600; aperture only goes down to f/8; shutter speeds only as long as 8s. You can enable picture modes such as natural, vivid, monochrome etc; however it does not work with bracketing or HDR mode: for HDR, it’s best to work manually.

One interesting point in favour of high-resolution mode: it does not stress the lens’s performance; at no point does it take an image of more than the native resolution, so if the MTF curves of contrast vs spatial frequency are adequate for 20 megapixels, the lens is also good enough for 50-80 (more later).

Hands-on: what’s it like in the field?

I took both current cameras out for a drive around the Highlands of Perthshire this afternoon, the NEX-7 with its kit 18-55mm lens and the Pen-F attached to a new 17mm f/1.8 prime.

Here’s a quick overview of four images: one from the NEX-7, two straight from the Pen-F’s own JPEGs out of camera (just downsized for presentation here) and one converted in RawTherapee:

My first real image from the Pen-F: Amulree and Strathbraan Parish Church at the end of Glen Quaich.

The Olympus images all have the same white-balance; I set the ORF and NEF files to the same whitebalance as the Pen-F chose automatically. It’s interesting that the sky is a proper shade of blue in the converted RAW; this might be a difference of profile between RawTherapee and the camera’s own internal JPEG engine. (Fine by me – I much prefer solid blue skies to cyan ones.)

What about the details?

Now this is a hard question. No doubt the resolution suffers and 80MPel is rather optimistic. Here we compare the NEX-7 against the 20MPel and 80MPel RAW files with no sharpening or detail controls enabled at all:

Obviously the 80MPel image is going to take a lot ofsharpening to bring it up to scratch.

My preferred sharpening algorithm with the NEX-7 has long been deconvolution. However, despite tweaking the radius, strength, dampening and iterations controls a lot, RawTherapee doesn’t seem to have the strength to sharpen the 80MPel hi-res RAW.

The out-of-camera JPEG appears to have a cruder sharpening algorithm with a lot of local contrast, so I switched to unsharp mask. At 80MPel, with enough USM to render the individual stones in the dry stone wall adequately sharp, this reveals serious anti-aliassing issues around straight-line edges:

Pen-F edge-aliassing artifacts

Pen-F edge-aliassing artifacts

These artefacts disappear when downsized to 50MPel in camera. Then again, the in-camera JPEG conversion is very contrasty and over-sharpened, so there’s room for improvement all-round:

In-camera JPEG conversion (20MPel) vs RawTherapee downscaled from 80MPel RAW

In-camera JPEG conversion (20MPel) vs RawTherapee downscaled from 80MPel RAW

Update: by adjusting the USM parameters, I’ve removed much of the artifacts around edges. There are still problems where blades of grass have moved between source frames, but static objects with strong outlines no longer cause such problems.

disable edge-only and halo-detection, just use less USM to start with

disable edge-only and halo-detection, just use less USM to start with

There are other demosaicing algorithms in RawTherapee and other ways of sharpening (newly added wavelet support). Plenty of scope for experimenting to get the best out of this thing.

What’s the verdict?

I absolutely love using it. Where other cameras drive the megapixel race by giving increasingly large images for everything (40MPel+), this camera ticks along at a more than adequate native 20 megapixels for most purposes with the option of taking one’s time to crank out the tripod to make absolutely huge images. This suits me fine – I’ve spent so long doing similar image-stacking/super-resolution trickery as part of the post-processing workflow, it’s great to have the camera do it instead.

The in-body stabilization is excellent. I managed to hand-hold 10 frames at 1/10s at the Falls of Dochart, twice, without a single blurry image.

There are lots of other features to look forward to – I’ve never had the patience to try focus-stacking, but moving it in-camera is very appealing.

With a subtle adjustment to the brighter blues to cater for skies, I could probably live off the camera’s own JPEGs for many purposes.

New lenses and filter adapter rings have been ordered…

Gratuitous sample images

As if the above weren’t nice enough, here are three more images from this afternoon.

Birnam Hill: Details

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A handful more photos from an afternoon stroll around Birnam Hill – little things that caught my eye. There was a small burn flowing down one of the paths, mostly covered in amazing semi-fractured ice crystals; patterns abound.

Ordinary Landscape

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The other day, we had a proponent of “creative landscape photography” presenting at the photographic society. His results were outstanding. I even approved of some of his philosophy, which is saying something.

But … some of his decisions in the execution of that philosophy seemed off.

It’s great to hear someone ignoring the maxim “get it right in camera”, espousing instead the idea of “getting good data at the scene” and affirming the role of post-processing to polish the result instead. I believe strongly in the very same thing myself.

It seems strange that such a philosophy would lead to rejoicing in a camera’s dynamic range – no matter claiming to have recovered 4 stops from the shadows, it would still have been done better by HDR at the scene – where the data comes from photons working in the hardware’s optimum performance zone.

It seems strange that one would criticize such a camera for “not seeing the same way we do”, and go on to say that we need to enhance the impression of depth by using lower contrast in the distance.
The sensor’s response curve is smooth; it will accurately reflect the relative contrast in areas by distance. The only way it would not is if one’s processing were to actively include tonemapping with localized contrast equalization. Left to its own devices, the result will accurately reflect what it was like to be there – one of the greater compliments a landscape photographer could receive.

The problem is not with the landscape; it’s with the way that photography should aspire to relate to the landscape. “Creative” seems to be a euphemism for multiplying and enhancing every aspect, be it strong foreground (make it a yet stronger perspective with a tilt lens), contrasty light (more contrast slider), colour (still more saturation and vibrace to breaking point) and so on. The results create impact but without story or message; visual salt without an underpinning of a particular taste.

Of course we know that “realism” is a phantom. It’s true that no camera will capture quite the same as anyone sees. However, let me introduce a new word: believability, precisely the quality that one could have been there at the same time. That seems like a valid goal.

Have some believable landscape images – they mean a little to me; that suffices.

Snowy Strathearn

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The view driving south-west along the A9 just above Forteviot is quite a treat – an open expanse of Strathearn with the river and road flowing through the landscape, bounded on the south by the Ochil hills.

On a snowy winter’s day with passing sunlight, even better!

Herewith, a few photos taken in the course of a few minutes as a filthy dark cloud rolled in.

When it snows…

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…it does it properly. A small handful of photos taken late one evening when all around was quiet (apart from some lunatic burning-out the clutch in their Ford to get up the road) and covered in white (and slush) and no light but streetlights…

Cromwell’s Tree, Bridge of Earn

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I took a long scenic detour home today, stopping in Bridge of Earn to search for Cromwell’s Tree having read about it in a book.

It’s easy to find – on the road heading south-west out of town, cross the railway bridge and it’s in the immediately adjacent field to the left.

The tree looks dead, but while the top half is a mass of dead bleached white remains of branches, the bottom third has fresh growth.

It’s known as Cromwell’s Tree as it commemorates the fact that Oliver Cromwell set up cam at Bridge of Earn in 1651. There is no documented evidence proving a direct link, but the tree is old enough to have been present in the 17th Century.

While I was there I found a pleasant reflection of the sky in a flooded field nearby.

The remotest glen?

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Late November, very late autumn – short days of chilly weather and cold light – I set off for a drive through Glen Lyon. I’d not been there for at least five years; felt like ages. Yet very little changes. The river Lyon still burbles on merrily past the Roman Bridge (that isn’t in any way Roman – it dates from the late 18th century); the mountains were all the same shape, with a light dusting of snow hinting at winter yet to come; the Scots Pine trees were still where I remembered them being (and, more to the point, I’ve since learned that they’re a remnant of the Caledonian Forest). There are, however, yet more potholes in the road from the dam at the end of the Glen up and over to Glen Lochay and someone’s plonked a cattle fence across the way. So it goes.

I had some fun with the Pentax 50mm f/1.8 lens, using it for landscapes (not a usual choice for me) and closeup work, even using a hole drilled in the lens-cap to make it into a pinhole.

Ansel had his “Moonrise, Hernandez, Mexico” moment. On the way back along the glen, I had my “Moonrise, Glen Lyon, Scotland” moment: the dullest of grey fading light, a clear view along between the mountains, dark bluey clouds passing rapidly in the distance and the moon rising beyond. Better yet, there were two boulders – one to climb, from which the other made a nice foreground feature. Click. Or more accurately, cliiiiiick, click, cliiiiiiiiiiiick – the sounds of a long exposure HDR sequence (1s, 0.25s, 4s) to capture the contrast on the scene. Categorically the best photo opportunity of the year.

I drove back over Ben Lawers in the pitch black with the rain turning to sleet.

Seeing the New Year in with style

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Over the course of New Year’s Eve I saw several aurora alerts. On checking, it was even visible as a pale grey band running above the neighbours’ houses, so I grabbed a camera and tripod and found a convenient path with a clear view to the north.

This was taken at a minute past midnight – some evidence of fireworks in Crieff with a wonderful aurora arcing over Strathearn.

Ringing-in the New Year with fireworks in Crieff from Auchterarder... with an aurora arching overhead.

Ringing-in the New Year with fireworks in Crieff from Auchterarder… with an aurora arching overhead.

Cultybraggan Camp

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Another set from a photo-excursion in May this year, directly contrasting with the pleasure of nature’s bluebells earlier in the day.

Cultybraggan is situated just outside village of Comrie. It was first used as a prisoner of war (PoW) camp during World War II and then became an Army training area before housing a Royal Observer Corps nuclear monitoring post and a Regional Government Headquarters. The camp ceased to be used by the military in 2004 and is now owned by the Comrie Development Trust.

The camp is also right on the line of the Highland Boundary Fault, running from Glen Artney straight through the camp and up through Dalginross and along the A85 through Strathearn.

Unusually for me, I’m trying a little artistic experiment – overlaying the same texture of trees (taken much more recently in Glen Lyon) over images, to see what can be made of it.

Bluebells

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It’s been a slightly busy year; so busy I’m still catching up with photos made in April / May time. Much longer and it’ll suit next year instead!

Around the middle of May a group of friends and I went for a photo-stroll from Crieff out along Lady Mary’s Walk, in search of bluebells. We found some. I shot some with an infrared filter, just to see what would happen – it seems to have rendered the colours with a very olde-worlde vintage faded effect.

Above Comrie

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A selection of photos taken around Glen Lednock, mostly up the Melville Monument overlooking Comrie.

This is Highland Boundary Fault territory; the fault itself runs up Glen Artney from the south-west straight through Cultybraggan PoW Camp, on through Comrie and across the A85 to the east.

I was also struck by how vintage Comrie itself looks from afar – a nice ratio of buildings interspersed by trees, with such a low vehicular traffic flow (even on a Saturday afternoon) that one could almost imagine the cars being replaced by carriages.

And no visit to Glen Lednock could be complete without the obvious long-exposure photo of the Wee Cauldron waterfall, of course!

Around Birnam Hill: landscape old and new

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The last in a small series of photos from Birnam Hill near Dunkeld.

As far as I can tell, the first two photos are taken more or less on the Highland Boundary Fault – a line runs from Stare Dam past Rohallion lodge, up through one quarry and across the A9 through another slate quarry.

Test shots from a favourite walk, playing with the new mobile – DNG RAW files processed in Darktable.