M42 on an Olympus E-420

gregmartin

Hello

I'm buying a wide angled 35mm lens, M42 fitting. Does anyone know the digital equivilant on an Olympus E-420 4/3 with a convertor. It's merely for documentation purposes I need to know really.

I've already been using a 300mm M42 fitting lens with a convertor, for nature shots, and they've turned out really well.

Thanks

gregmartin

Seymore wrote:

Welcome to DGRIN Greg... Looks like the E-420 has a 2x multiplier. So that will make your lens a 70mm film equivalent.


HTH...

It does. Thank you. And thanks for the welcome. I didn't realise it was that simple for my camera.

craig_d

gregmartin wrote:

I didn't realise it was that simple for my camera.

It's that simple for pretty much any camera, though the multiplier varies according to the camera's sensor size. Your Olympus is a Four Thirds camera, and all Four Thirds cameras have a 2x multiplier compared to traditional 35mm. Just take the lens's focal length and double it to determine the equivalent field of view.

gregmartin

Thanks. I've just taken on a DSLR after using a film SLR for ages. I'm probably looking for something being more technical than it probably is and many of the examples from google were quite complicated, or seemed to be made that way.

I assume you mean it's 2x multiplier at the sensor itself? So less field of view through the lens. But that's ok for me, as I tend to crop my shots anyway. So it might mean less cropping

craig_d

gregmartin wrote:

I assume you mean it's 2x multiplier at the sensor itself? So less field of view through the lens.

Right, because the lens doesn't change, it's just that the camera is recording a smaller area of the image circle. A 35mm camera takes a 36x24mm rectangle (43mm on the diagonal) from the middle of the image circle, but a Four Thirds sensor takes only about 17x13mm (22mm on the diagonal). So the field of view is reduced by about half. The larger the multiplier, the smaller the sensor. For comparison, any model of Canon Digital Rebel has a 1.6x multiplier, and most Nikons are 1.5x. There are also a few full-frame 36x24mm digital models, including the Canon 1Ds and 5D, Nikon D3 and D700, Sony A900, and the Leica M9 rangefinder.

gregmartin

craig_d wrote:

Right, because the lens doesn't change, it's just that the camera is recording a smaller area of the image circle. A 35mm camera takes a 36x24mm rectangle (43mm on the diagonal) from the middle of the image circle, but a Four Thirds sensor takes only about 17x13mm (22mm on the diagonal). So the field of view is reduced by about half. The larger the multiplier, the smaller the sensor. For comparison, any model of Canon Digital Rebel has a 1.6x multiplier, and most Nikons are 1.5x. There are also a few full-frame 36x24mm digital models, including the Canon 1Ds and 5D, Nikon D3 and D700, Sony A900, and the Leica M9 rangefinder.

Great information Craig. Thank you very much.