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.

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!

Using Old Manual Focus Lenses on a DSLR

If you’ve bought your new DSLR with a kit lens, it will do a good ‘general purpose’  job.

However most aren’t that ‘fast’ i.e. they have fairly small minimum apertures (f3.5 to f5.6 for a 15-85mm Canon), so for isolating a subject with narrow depth of field and nice ‘bokeh’ they’re not great.

This post shows a way to get that ‘look’ without spending a fortune.

Shallow Depth of Field – Helios 85mm f2

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