Christopher J Osborne

Olympus Pen F lenses on full-frame digital

The Olympus Pen F system, launched in 1963, is the only interchangeable lens camera system ever designed from the ground up for the 35mm half-frame format. The 35mm half-frame negative is (as its name might lead you to expect!) 24x18mm, exactly half that of the 35mm full-frame format. This make Olympus Pen F lenses especially suitable for use on APS-C digital cameras, the format of which (23.7x15.7mm for most cameras) is only very slightly smaller. This means you are using the lenses mostly within their intended scope of use.

It also means that these lenses were never intended to be used on full-frame cameras, so you'd be crazy to even consider doing so, wouldn't you? Well, yes and no! It turns out that many of the Pen F lenses have bigger imaging circles that you might think. Several of them produce images with only a little easily correctable vignetting, and many of the other require much less cropping than their intended use on half-frame cameras would suggest. Outside of that half-frame area the sharpness often drops of considerable, and if you're sensitive to such things you might still want to crop anyway.

But I rather like the effect! I found that whether I like the lack of sharpness in the corners on any particular image depended on a number of factors, but most importantly the type of subject. For example, if you have tree branches in the corners of you image the effect can be quite disturbing. But a piece flat stone wall often looked quite good with the burry corners. And of course if shallow depth of field leads the corners to be out-of-focus anyway it's also of much less consequence. And this is where using these lenses on full-frame makes a lot of sense: you can crop each individual image on a case-by-case basis to make the most out of the available field of view.

I am lucky to own all but 1 the Pen F lenses with a focal length of 150mm or shorter (I am missing the very rare and desirable 42mm f/1.2 lens), and I thought it would be an interesting experiment to see how they all do on full-frame, hence this page. My original intention was to shoot exactly the same brick wall with each lens, but my lack of patience (and my desire to actually have some fun!) defeated that plan. In the end I decided to shoot real-world photos to give you a good idea of the kind of finished results you can create with these lenses on a full-frame digital camera, in my case a 24mp Sony A7 MkII.

For each image you will find 3 versions:

1. OOC+EC (out of camera, plus exposure correction)

   The first version is almost straight out of camera image with only light exposure correction (usually nothing more than hitting 'auto' in the Lightroom 'tone' panel) to make the imaging circle easier to see, especially if the image is a bit dark because of under exposure.

2. Cropped

   In addition to the exposure corrections, the second version has received a simple crop to give the widest view possible, allowing a little easily correctable vignetting. (For those images that do no require cropping I may miss this version out!)

3. Final

   The third and final version is a finished photograph with all the processing necessary to achieve the photograph I am looking for. This might include further cropping (often to a 4:3 aspect ratio), correction of rotation and converging verticals, further exposure corrections, maybe adding some creative vignetting, and in many cases conversion of black and white using Silver Efex Pro 2.

For the cropped and finished versions I will give you the resolution in megapixels, and the effective 35mm equivalent lens focal lengths to give you an idea of how much cropping was necessary.