The Zuiko 24mm f2.8 on a Sony A7R

Continuing this series of mini reviews of my favourite old lenses on the beefy A7R’s 36Mp sensor, this time it’s the turn of the tiny Zuiko 24mm f2.8. This was a cracker of a lens on the APSC Canon 60D so I’m hoping for lots of good things…. All shots taken in RAW mode and ‘developed’ in DXO Optics 9 using default settings.

Sony A7R, Zuiko 24mm f2.8

The 24mm doing what it does best – cramming lots of landscape into the frame.

The most striking thing about this all metal lens is its size – a shade more than 3cm (1 1/4 inches) long and weighs in at 220g (7.8 oz). It has almost the same dimensions as the Zuiko 50mm f1.8, and is about as small as it’s possible to make a manual focus lens and keep it useable. It accepts 49mm filter, apertures run from 2.8 to 16, the minimum focus distance is about 25cm and the aperture is – unfortunately – made up of only six blades which means hexagonal bokeh – if you ever see it with such a wide-angle lens.

Sony A7R, Zuiko 24mm f2.8

Take off the lens cap and the filter and it’s even smaller!

Ergonomically on the A7r it’s perfect – the focussing ring is smooth and well geared and the camera/lens combo is wonderfully light and easy to use.

Sony A7R, Zuiko 24mm f2.8

This looks like a mid era model – maybe late 1980’s?

With an angle of view of 84 degrees it’s noticeably wider than a Zuiko 28mm lens (75 degrees) and not that far off an 18 mm lens (100 degrees) or the 21mm Zuiko (92 degrees). With this level of ‘wide angle-ness’ verticals start to heavily distort if the camera isn’t parallel with the subject so unless you really like correcting this in pp, be careful!

Sony A7R, Zuiko 24mm f2.8

Just a slight tip upwards produces converging vertical. Fixed easily in pp.

Vignetting is obvious at f2.8, gradually fading to nothing by f8 – nowhere near as bad as the Zuiko 18mm f3.5 at max aperture (few lenses are!) but something to bear in mind.

Sony A7R, Zuiko 24mm f2.8

Sharp, good colour and snappy contrast – looks good.

The contrast and colour are all as good as they were on the Canon 60D, but the A7R seems to over saturate greens with this lens which is odd but there you go.

Sony A7R, Zuiko 24mm f2.8

This isn’t the worst example of flare I could have shown – it’s just that it’s so ugly when it happens I didn’t want to take the shot!

Flare is a big problem with this lens, and the hexagonal nature of the aperture makes things worse. To be fair, most old MF lenses suffer from flare to some degree but this is worse than most. A lens hood won’t help much on such a wide-angle lens so you just have to be careful and recompose if necessary.

Sony A7R, Zuiko 24mm f2.8

That contrast and colour again – excellent.

Chromatic aberration is minimal, probably removed easily by DXO Optics 9 when processing the RAW files for this test, so a major plus.

Sony A7R, Zuiko 24mm f2.8

It’s possible to create some nice converging lines by getting in close and letting the wide-angle distortion do it’s ‘thing’.

Resolution then – on to the mill.

The whole frame (showing that vignetting nicely at f2.8).

Sony A7R, Zuiko 24mm f2.8

f2.8

Centre

Sony A7R, Zuiko 24mm f2.8

Edge

Sony A7R, Zuiko 24mm f2.8

f5.6

Centre

Sony A7R, Zuiko 24mm f2.8

Edge

Sony A7R, Zuiko 24mm f2.8

f11

Centre

Sony A7R, Zuiko 24mm f2.8

Edge

Sony A7R, Zuiko 24mm f2.8

f16 (just for completeness)

Centre

Sony A7R, Zuiko 24mm f2.8

Edge

Sony A7R, Zuiko 24mm f2.8

The positive first then – the superb resolution at the centre is obvious from f5.6 to f11 just as it was on the Canon 60D. f5.6 is especially impressive. The obvious problem though is edge resolution – it’s very poor at f3.5, cleans up a little by f11 where it’s still not that good, and by f16 everything is starts to fall apart again due to diffraction. Quite a disappointment as I had high hopes for this lens.

This doesn’t appear to be a problem with the adaptor as the right hand side of the frame is just as bad as the left. I mention this after reading Lensrentals analysis of using adaptors with non-native lenses here (it’s an interesting article!).

All in all then, something of a mixed bag on a full frame camera. Centre resolution is excellent at the right apertures, colour and contrast are good, chromatic aberration never makes much of an appearance and distortion is controllable if it’s used properly. It’s wonderfully small and light and a joy to use. Set against that is pretty terrible flare, vignetting till f8 and the poor edge resolution.

If you aren’t too picky this isn’t bad for the price (sub £100), but it’s effectively a 24mm f5.6 (to f11) lens if you want the best results and I would imagine a modern zoom lens would beat it hands down at the edges (maybe not the centre!). On an APSC sensor where the weak edge definition and vignetting don’t matter so much it’s a different story, and for smaller sensors I can heartily recommend it as a 35mm – 40mm standard lens. For full frame sensors though it’s not quite so easy to recommend.

Thanks for looking, hope you find this useful.

If you’re interested in using other MF lenses have a look at the other reviews on the film, camera and lens review index tab.

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The Sony A7R and a Helios 85mm f2

This little review is done out of pure curiosity. The Russian made Helios Jupiter 85mm f2 is not known for it’s sharpness (Zeiss have nothing to worry about here), more for the unusual characteristics of the images it produces which I’ve found in the past to be unique. I’m not expecting much at all here so this should be good fun.

Sony A7R, Helios Jupiter 85mm f2

That magic bokeh is back!

 

For around £8 a NEX to M42 screw mount adaptor was ordered, and it’s pretty well made, with three allen key loosened grub screws to allow the fixed lens to be rotated so the top of the lens aligns with the camera. What this does for the alignment of the lens with the sensor plane is anyone’s guess but let’s not worry for now. There is no electronic contact between lens and camera so no EXIF data for the lens or aperture used. Obviously there’s no autofocus, apertures are set manually and forget image stabilisation.

Sony A7R, Helios Jupiter 85mm f2

On the A7R – this is about as heavy as it’s possible to go on the small A7R body without things feeling unbalanced (for me). The adaptor adjustment grub screws can be seen on the right hand side of the adaptor.

 

The lens is solidly made in metal and quite compact, but feels heavy (13 oz/374g). Minimum focus is around 75 cm (about 30 inches) and it shares a 49 mm filter thread with most Zuiko prime lenses. Focus from infinity to minimum distance takes around 270 degrees. The weight helps stabilise the camera/lens but there’s no image stabilisation (not invented when the lens was made!) so 160th of a second or shorter for hand-held shots is best.

Sony A7R, Helios Jupiter 85mm f2

Without the adaptor and front UV filter it’s quite small and ‘dense’. Controls from left to right – grip for screwing the lens on to the adaptor, the knurled focus ring, the ‘stop down the aperture to what’s been selected’ ring and the ‘set the desired aperture’ ring

 

The aperture blades maintain a circular shape at all apertures, and look quite different from most lenses. Rather than being matt black they appear to be bare metal which looks a bit ‘industrial’, just like the rest of the lens in fact. The ‘stop down’ nature of the lens means it’s best to leave the front aperture setting at f16 then just rotate the inner ring across the aperture range until things look good. This means you have no idea what aperture is being used. If you’re very patient you could do it correctly and set the aperture on the front ring then rotate the inner ring completely to the right. I’m not that patient.

Sony A7R, Helios Jupiter 85mm f2

Shiny and worn aperture blades maintain a circular shape at all apertures – no hexagonal out of focus points!

 

Focussing isn’t as easy as with the sharp, contrasty OM Zuiko lenses. The ‘focus peaking’ feature relies on image contrast to sprinkle the view finder with ‘in focus’ pixels, but as this lens isn’t too sharp and of low contrast it didn’t show much. With the ‘focus magnify’ focussing was much easier, but at the maximum ‘zoom in’ level you can actually see how soft the image is at maximum aperture. It’s very much like focussing a Lensbaby – there’s nothing really sharp ‘out there’ through the lens so just do the best you can. Combined with the extra care needed shooting with the A7R this combination means slow, deliberate photography.

Sony A7R, Helios Jupiter 85mm f2

Soft and dreamy – nice.

 

There’s a little vignetting wide open but only if you’re looking for it. Flare can be quite bad as the front element isn’t multicoated (it may not be coated at all). Contrast is low across the aperture range (images look terrible before post processing) so shoot in RAW and be prepared for some moderately serious post processing – all in a day’s work for MF lens users.

Sony A7R, Helios Jupiter 85mm f2

Nice smooth bokeh – lovely

 

If image sharpness or ease of use are your goals look elsewhere – very far away! This lens excels at producing soft ‘dreamy’ images at closer focussing distances with some very shallow depth of field and attractive bokeh. Traditionally used for portraits, these characteristics lend themselves to a few other subjects such as flower, food and ‘special effect’ photography.

Sony A7R, Helios Jupiter 85mm f2

At medium distances the edges of the frame can get quite ‘swirly’ – like a poor man’s Petzval lens.

This lens did quite well on a Canon 5D Mk2 and a 60D as the poor resolution wasn’t so mercilessly exposed on 20Mp and 18Mp sensors. It was however more difficult to focus through the optical viewfinders of these cameras so sort of a draw there. Using this lens is a huge waste of 36Mp of resolution (8Mp might be appropriate), but as the A7R is now my main camera, I’m not carrying another one just for this lens!

Sony A7R, Helios Jupiter 85mm f2

It’s rather good for ‘book cover’ type stuff.

 

Sony A7R, Helios Jupiter 85mm f2

At f2 and soft everywhere even the bits in focus – but it all sort of ‘works’

 

For tradition’s sake, let’s do a centre enlargement from a shot at f8 :-

Sony A7R, Helios Jupiter 85mm f2

The full image

 

Sony A7R, Helios Jupiter 85mm f2

The centre enlagement – forget the edges at all apertures. Not great – but – not what it was designed for.

 

So, is this a useful lens on a Sony A7R? For me it is, as my specialist market is book covers, and a ‘different’ look at the expense of sharpness can sometimes sell (this lens paid for itself in sales many times over on other cameras). For the narrow range of subjects it’s designed for its great (and cheap), for everything else it’s pretty useless. Despite it’s shortcomings I really like this lens – it’s got ‘character’.

Thanks for looking – hope you find this useful.

If you’re interested in using other MF lenses have a look at the other reviews on the film, camera and lens review index tab.

The Zuiko 28mm f2 on a Sony A7R

For a short while I’ve managed to wrench the excellent Zuiko 50mm f1.4 from the Sony to see how well my old favourite lens performs. I’ve found this to be a very good lens on other cameras so I’ve high hopes!

Zuiko 28mm f2, Sony A7R

Salisbury Cathedral from the ‘classic’ viewpoint. Looks good so far.

The lens is slightly longer than the 50mm f1.4 but still extremely compact. The aperture range is f2 to f16, minimum focus is around 30cm (or one foot) and the filter size is a standard (and cheap) 49mm.

It’s nicely balanced on the Sony, just like the 50mm. Focussing is slightly more difficult that the 50mm, presumably because of increased depth of field, but the ‘focus magnify’ button is your friend here and usually gets the job done. Operating the combo of camera and lens feels fast and easy.

Zuiko 28mm f2, Sony A7R

The combo from above – light, portable and easy to use – can’t fault it really.

Surprisingly I’m finding that manually focussing is producing much sharper results than autofocus systems on other cameras. Here’s an article on how phase detect autofocus works http://www.lensrentals.com/blog/2010/07/how-autofocus-often-works, and having seen how shallow the ‘really in focus bit’ is using focus magnify I can understand why. No anti-alias filter helps the sharpness a lot, but really shows when you’ve got the focus wrong.

It seems working slowly and deliberately is required to get the best from 36 Mp of resolution as some slightly mis-focussed shots have illustrated! It goes without saying that the depth of field scale on the lens and the focus peaking feature on the A7R aren’t to be trusted for best results.

Zuiko 28mm f2, Sony A7R

Using the ‘neutral’ colour profile and setting the white balance in post processing results in some very accurate colour.

Colours and contrast are good, though there is some vignetting at f2 as you would expect. There’s no image stabilisation with this combo so 1/60th is the absolute minimum hand held shutter speed for me – anything slower use a tripod or a monopod.

Zuiko 28mm f2, Sony A7R

Inside Sherborne Abbey and looking up at the spectacular fan vaulting, a good resolution test. The detail in the full size file is amazing!

Flare isn’t as well controlled as modern lenses, but it’s not too bad – there’s a hint of it around the windows in the above shot.

Zuiko 28mm f2, Sony A7R

Bokeh with a 28mm lens – if you want it you can do it.

Bokeh isn’t a feature usually associated with wide angle lenses due to the deep depth of field, but f2 is pretty fast and you can create some nice out of focus effects at close focus distances.

Right then, the standard test :-

Zuiko 28mm f2, Sony A7R

Full frame at f2. The vignetting is visible here, but apart from that not bad at all.

 

Zuiko 28mm f2, Sony A7R

The centre at f2 – a bit soft but useable in all but huge enlargements.

 

Zuiko 28mm f2, Sony A7R

Centre at f8 – nicely sharpened up and good enough.

 

Zuiko 28mm f2, Sony A7R

The extreme edges however never really get bitingly sharp, just ‘good’. This is at f16 but f5.6 and f8 are the same. Don’t ask about the edge at f2!

In conclusion then, a well behaved lens capable of very good results at smaller apertures, and fast enough to allow shooting in lower light if you’re prepared to accept softer images. Is it making the most of the 36Mp sensor? Not really, especially at the edge, so if you’re a very demanding photographer it might be best to look elsewhere. It is however more than capable for all but the largest enlargements and with it’s compact dimensions, a perfect physical match to the A7R.

The very best part of using these lenses is that I now sometimes leave the camera bag behind altogether, carrying the 28mm and a 135mm lens in each jacket pocket, and the 50mm on the A7R. To be able to do this and get files which exceed my agency’s image requirements is nothing short of fantastic!

Unless someone comes up with a reasonably priced, compact and outstandingly good 28mm I’ll stick with this as it’s more than good enough for my purposes.

Thanks for looking, hope you find this useful. A similar test of the 50mm f1.4 is here.

If you’re interested in using other MF lenses have a look at the other reviews on the film, camera and lens review index tab.

Olympus Dramatic Tone Long Exposures

Looking for something new to try on a photo trip out to Swanage in Dorset, I had the diminutive EPL5 and some neutral density filters rattling around the camera bag so thought I’d try some long exposures using the ‘Dramatic Tone’ art filter.

Olympus Pen, Dramatic Tone, long exposure

Four seconds at f18 with the camera firmly braced against a sea wall produced this – not bad at all.

 

This special effects filter produces some spectacular results, pushing the contrast in the midtones and dragging detail from otherwise overcast skies. While shooting, the results look great but looking at hundreds of shots later when processing them brings home a sinking feeling – this effect should only be used sparingly as too much of it becomes tiringly repetitive!

Olympus Pen, Dramatic Tone, long exposure

Two seconds at f22 and more streaky seabirds….

 

Two stacked 58mm x3 ND filters on a hairy contraption of 37 ->49 then 49 ->58mm step up rings allowed their use on the tiny 14-42mm kit lens. When things briefly brightened up a circular polarizer was added to cut the light getting through to the sensor was added too! The resulting JPEGs were post-processed in DXO Filmpack using some of the ‘designer’ presets to give a toned result which adds an extra dimension to the monochrome images.

Olympus Pen, Dramatic Tone, long exposure

A river discharges into the sea here and there’s always a lot of seagulls milling around. The streaks in the sky are them flying past. Two seconds at f22.

 

The Oly’s IBIS (in body image stabilisation) and hand holding the camera on various posts, railings etc at exposures up to 8 seconds at f16-f22 worked reasonably well but there were around 50% failures due to camera shake (I was pushing things to extremes here!).

Olympus Pen, Dramatic Tone, long exposure

One second at f22 was all that was need here

 

There were a few dust spots on the sensor which have been cloned out – and the sensor given a quick clean. The processing required to create these if shooting in RAW+JPEG takes a few seconds at normal shutter speeds. With long exposure noise reduction processing added, it takes around five seconds to process and save each shot so don’t expect this to be a quick process.

Overall I’m reasonably pleased with this as a technique. It adds an extra twist to the well trodden ‘Dramatic Tone’ approach and might be useful for art print sales – though I can’t see it being much use for book covers. Mainly though, it’s simply good fun – give it a try if you have a chance.

Thanks for looking, hope you like them.

A Stormy Day and Some Long Exposures (and some myths debunked!)

We’re having some stormy days in Dorset lately which is a good excuse to get the tripod and neutral density filters out and do some long exposures on the coast. All shots on a Canon 60D using a Sigma 10-20mm f4-5.6 lens.

Canon 60D, Sigma 10-20mm f4-5.6

Kimmeridge Bay and Clavell’s Tower. 10mm focal length, 15 seconds at f16, heavily tweaked in DXO Filmpack using the Rollei Retro 80s film profile – then even more contrast was added! The composition was helped by the very strong wind blowing the clouds and waves straight at the camera.

There isn’t a great amount of light around, but if shutter speeds of up to thirty seconds at ISO 100 are to be used, a x8 (three stop) ND filter isn’t enough by a long way. There were all taken using a stacked pair of x8 and x64 (six stop) Hoya ND filters and even then f16, f22 and f32 were all used to get long enough shutter speeds. The first myth to be debunked here is that old rule ‘never go below f16 – resolution will suffer because of diffraction’ – here the advantage of a slow shutter speed easily outweighs any slight softness created by a small aperture so just use it anyway!

Surprisingly there was no vignetting from the stacked filters.

Canon 60D, Sigma 10-20mm f4-5.6

3.2 seconds @f25. This one at the same location was taken with a view to converting it to a ‘moonlit light’ type shot. The brightness is dropped and a blue tint added to give the illusion of a moonlit bay. I’ve just finished reading ‘Moonfleet’ so that’s probably what made the shot come to mind.

The second golden rule which didn’t seem to apply was that muck on a wide-angle lens at small apertures will spoil a shot as it will be visible. I’ve always meticulously cleaned the front filters of such lenses, but despite the front filter being caked in dried salt and sand by the end of this shoot nothing was visible on the shots – at 10mm focal length using f32 in some shots! Something else not to worry about!

Canon 60D, Sigma 10-20mm f4-5.6

A bit more abstract – f13 10 seconds. Post processing as per the first shot.

It’s best to take lots of shots at different apertures and shutter speeds as the variation between different wave timings and slow shutter effects is remarkable. I couldn’t predict how the waves were going to hit the beach so just took ten or so shots at each tripod location – even then some weren’t too good. This is pot luck in short!

A heavy tripod is recommended and even then don’t extend it but use it at it’s lowest setting with the centre column down. Strong winds were shaking the camera with the legs extended by even one section and if it blows over onto rocks in salt water it’s probably time to wave the camera and lens goodbye….

Canon 60D, Sigma 10-20mm f4-5.6

2 seconds f10 with the wind blowing from left to right. Post processing as he first shot.

I had more difficulty than ever keeping the horizons straight so several of these were straightened in pp. Composition in a gale is more difficult than it looks even using the flip out LCD and grid lines – the viewfinder is very dark due to the ND filters and close to the ground which means it isn’t very comfortable to use.

Canon 60D, Sigma 10-20mm f4-5.6

5 seconds @f5.6.

For these conditions shutter speeds of 2 seconds to 15 seconds produced the best results. At 30 seconds the sea became too ‘blurred’, below 2 seconds and not enough movement was captured.

A very different location – the sheltered marshes behind the dunes at Studland and the pool surface was just being ruffled by the wind.

Canon 60D, Sigma 10-20mm f4-5.6

5 seconds @f10. Generic Ektachrome film profile in DXO filmpack brought out the red hues which contrast with the blue sky reflection.

Next a similar shot at the same location.

Canon 60D, Sigma 10-20mm f4-5.6

5 seconds at f10 – a blue cast seemed to suit this one but it would work well in black and white.

Finally it’s worth mentioning that the most important kit when shooting stormy weather near the coast isn’t camera kit at all – good outdoor clothing is essential otherwise you’re likely to get freezing cold and wet – not good for concentrating on photography (sorry to nag).

DN0A0105

What not to do (as I did) – get caught by a large wave (it’s on it’s way out in this shot) which overtops not particularly waterproof boots, giving you freezing cold, wet feet for the rest of the day. Oh – and almost lose your camera at the same time! Thanks for the picture Jayne even if you were laughing when you took it. The first picture on this post was taken when this happened so it was worth it.

The best part of shooting in bad weather is that you feel that you’ve done something productive rather than sit around indoors and I really must do more of it. With better boots, a towel and a spare set of socks next time though.

Thanks for looking – hope you like them!

The Lensbaby Sweet 35 on a Canon 5d Mk 2

The next lens in line for a mini-test on a Canon 5d Mk2 is the Lensbaby Sweet 35, a 35mm fixed focal length special effects lens used for many years on a 60D. The ‘test area’s for these shots were Kimmeridge Bay and Corfe Castle in Dorset (UK) , both popular with summer visitors. By using the Lensbaby I was hoping to blur away the modern ‘clutter’ and get a more timeless set of images. The Sweet 35 was in a ‘Composer’ mount, and all shots processed in DXO Optics 9 and Filmpack 4.

Canon 5d Mk2 Lensbaby Sweet 35

First shot – Corfe Castle. The Lensbaby at max aperture has done a great job of ‘eliminating’ the tourists swarming around the base.

In use it’s a nice surprise to have something small and light attached to the heavy 5D body rather than a bulky zoom lens.

Canon 5d Mk2 Lensbaby Sweet 35

A second shot from inside the village – this has worked well – the area under the houses was full of cars and pedestrians!

Focussing is easy on the large screen but best of all it’s now a proper 35mm lens rather than a 56mm equivalent on the 60D, giving a moderately wide angle view. After years of wanting a wider view on crop frame sensors using this lens, this is brilliant!

Canon 5d Mk2 Lensbaby Sweet 35

Some distracting telephone wires and TV aerials have been blurred away on this one – certainly easier than the Photoshop clone tool….

On to Kimmeridge for this shot.  The romantic tower on the cliff is Clavell’s Tower – available for holiday lets as long as you’re willing to book several years in advance.

Canon 5d Mk2 Lensbaby Sweet 35

I’d never seen these odd circular out of focus areas (see lower left) on the 60D – looking at them they are at the edge of the frame so the smaller sensor probably didn’t see them. They only occur at max aperture.

Not a bad result at all. Apart from the odd bokeh seen in the last shot, the wider angle of view is very welcome, and on full frame, the blurry edge of the frame is even more effective.

Hope you find this useful, thanks for looking.

If you’re interested in using other MF lenses on your DSLR have a look at the other reviews on the film, camera and lens review index tab.

One Manual Focus Lens, Three Cameras

Sensor format and lens focal length is one of the most puzzling aspects of digital photography. Everyone probably knows smaller sensors mean increased depth of field for a given focal length and that sub 35mm frame cameras have smaller focal lengths to achieve the same angle of view. This creates the 2x focal length ‘crop factor’ on a Micro Four Thirds format, a 1.6x on APS_C and, well, 1.0x  on full frame 35mm. How much difference does this make in terms of depth of field (or depth of focus)? I’ve always wanted to try this out, so time for a play – a test, sorry.

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

A ‘full frame’ 20Mp Canon 5d Mk2, an 18 Mp  ‘APS-C’ 60D and a 16Mp Micro Four Thirds Olympus EPL5 (with Micro four Thirds to EF lens mount adaptor attached). The lens is a venerable Zuiko 50mm F1.4 from the Oly 35mm film days. All three needed an OM to EF adaptor.

There’s a nice diagram illustrating the difference in sensor sizes here (Wikipedia). All shots taken in RAW, converted to JPEG using DXO Optics 9.

Firstly – field of view. These next three are all shot from the same tripod position at f1.4.

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

5D Mk2 at 1.4. Apologies for the edge of the card at the bottom – I hadn’t quite anticipated how wide 50mm was going to be as I started this series on the EPL5. Oops. Note the vignetting at the edge of the frame – quite common for a fast lens at maximum aperture.

On the 50D it’s a 50mm x 1.6 so an 80mm equivalent :-

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

As only the centre portion of the image is used, no vignetting!

On the EPL5 its 50mm x 2 so a 100mm equivalent :-

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

The shot here is wider than either of the Canons due to the ‘aspect ratio’ of Micro Four Thirds (in plain english the sensor produces images which are effectively ‘fatter’ in portrait mode and ‘taller’ in landscape mode).

What’s happening here is that although the effective focal length is changing, the depth of field from the same shooting position is the same for all three lenses – the smaller sensors are just sampling a smaller rectangle of the same 35mm image circle. The EPL5’s image is like an enlargement of the centre of the larger sensors’ images. It’s worth bearing in mind that the EPL5 has more pixels in it’s frame (16Mp) than an equivalent cropped 5DMk2 image (around 12Mp I’d guess).

Now – to try to create the same shot with all three cameras. This isn’t as easy as I first thought! What’s expected is that there will be greater depth of field on the smaller sensor as we’re further away from the subject. The common focus point is the blue reel of cotton with the red spool, focussed using the LCD and focus magnify.

First the 5d Mk2 (50mm) :-

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

Razor thin depth of field – the furthest grey cotton reel is just a vague blur.

Then the 60D (80mm equivalent):-

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

Taken from a position further from the subject. Still very narrow depth of field but the far cotton reel is now visible.

Then the EPL5 (100mm equivalent)-

Canon 5d Mk2, Canon 60D, Olympus EPL5, Zuiko 50mm F1.4

Even more depth of field – that far grey cotton reel is now clearly visible.

Something of a surprise here – the difference in depth of field between the EPL5 and the 5dMK2 is obvious, but between the 60D and the 5dMk2 it’s not as great as I would have expected.

What this little experiment confirms is that for any given lens – in this case a 50mm f1.4 – the effective depth of field for smaller sensors is deeper than larger sensors when taking the same photograph. It’s still an  f1.4 lens for exposure purposes, but for blurring away a background and isolating a subject the large 35mm size sensor is better.

However, not everyone wants shallow depth of field – if you don’t, these results could be seen the other way around! It all depends on what you’re trying to achieve.

For macro, landscape and telephoto photography (where depth of field is at a premium) I can see ‘Micro Four Thirds’ having an advantage.

For portraits and isolating subjects against a blurred away background ‘Full Frame’ is a winner with ‘APS-C’ not far behind it.

For general photography using intermediate focal lengths at medium to infinity subject distances there isn’t that much difference (I’m not taking into account high ISO noise, cost or any of the tens of other differences between sensor formats).

Hope you find this useful – thanks for looking!