Dark, lighter, lightest

light lighter lightest
When I switched to medium format, I wasn’t worried about the fixed lens. There are plenty of shots I can’t get – some of my results in the Alps were a real disappointment because there wasn’t enough snow to fill the frame – but it doesn’t bother me. Not really. But when I saw a 2x converter on ebay I snapped it up. It was cheap as chips, and I wasn’t even sure how it worked but it was worth a risk.

But even though my test shot came out pretty well – the focus was crisp and bright, I only used it once. Then when a friend decided to get a 120 lens for her Blad, it reminded me to get my 2x converter out and give it another try. I knew you had to do something but I couldn’t remember what I should stop down to. A quick look on wikipedia left me completely confused so I grabbed the only photography reference book I could find among the muddle of unpacked boxes and ran out.

Over lunch we sat and read the book. I’m still not quite sure what “A x2 converter will double its focal length but will also reduce the maximum aperture available by two f numbers” means. Does it mean I can’t use the lowest aperture or do I just need to remember that when I choose 2.8 I am really choosing 4, or is it 5.6?

In the end we figured out that I probably needed to take a meter reading and compensate by 2 f-stops, or change the shutter speed by the same amount. So these 3 shots were taken at what the light meter suggested, then opening the aperture one extra notch and finally two extra notches. And then just like now as I’m writing this, the penny finally drops. If the lens reduces the aperture, then I have to compensate and increase it.

Now all I need is to find a way of fixing that in my brain so I can get out and use the thing a bit more.

Of course I could take the simple route and buy a new lens. But where would be the challenge in that?

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6 comments

  1. I suppose more glass means less light gets through hence the -2 stops or -2 shutter speeds. Sometimes they are -3.

    Related, what is the equivalent of a 50mm ‘normal prime’ on a Hasselblad? With a bigger focal plane, does that mean 85mm is ‘normal’?

    And a new brown template! Great for photography! 😉

  2. It means that at ultra wide open, you’ll see the converter as a tunnel in the frame. Try it, looks interesting, I’ve stacked filters for the same effect.

    80/85/90 is 50mm equiv.

  3. Thanks Stewie. At least it’s all multiples of the same number.

    phojus – I could, as long as I worked out by how much.

    rashbre – I think there’s some of that, and what Brenda said. Glad you like the template – I really wanted grey but th options are limited and brown is a good compromise.
    Brenda – Thanks for the tip – I did try it out, and you can see the edge of the converter when the lens is wide open.

    Thanks Dave. I’m one of those people who learn best by practical methods. Looking at the lens as Brenda suggested was a big help.

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