peleng 8mm f/3.5 fisheye (and a 8mm computar c-mount lens) on the panasonic gf1

After purchasing my Panasonic GF1, I thought it’d be fun to exploit the small form-factor and smaller sensor and try some of the c-mount lenses that are out there on the micro 4/3rds camera.  I purchased an adapter off of ebay that had both c-mount and M42 threads.  I tried it with a TV lens that I bought off of ebay, and then an 8mm lens that I already had for my canon.

computar 8mm f/1.6:

I tried the 8mm computar first:

computar 8mm f/1.6 fixed aperture tv lens

It’s a fixed-aperture lens that only cost about $5 or $10 from ebay.  I didn’t have high hopes – just wanted something to play with.

Here’s a sample image taken with that lens:

sample image taken with panasonic gf1 and computar 8mm f/1.6 tv lens
sample image taken with panasonic gf1 and computar 8mm f/1.6 tv lens

The image circle isn’t very large, and it’s not very sharp.  oh well.  The lens could still be useful for video – the GF1 gives a 2x or 4x digital zoom option, and with 2x digital zoom there’s no vignette.  the 2x digital zoom results in an 32mm 35mm-equivalent focal length though, which isn’t much wider than the standard 20mm f/1.7 kit lens.

peleng 8mm f/3.5 fisheye:

peleng 8mm f/3.5 fisheye mounted on a panasonic gf1, side view
peleng 8mm f/3.5 fisheye mounted on a panasonic gf1, side view
peleng 8mm f/3.5 fisheye, isometric view

The Peleng is a little larger than the computar.  I had to buy some cheapo M42 extension tubes to get the flange/sensor distance within a correct range.   I used the wikipedia table to guesstimate how much more distance I needed, and the 9mm + 16mm extension tubes did the trick just fine.

It’s a bulky lens, and turning the aperture and focusing rings isn’t so easy on such a small-bodied camera.  You have to grip the body really tightly in order to turn the damped focusing ring and the detented aperture ring.  Luckily, at 8mm and f/3.5, everything’s basically in focus.

Photos with the fisheye are still fun in a fisheye sort of way:

primo's parilla on the panasonic gf1 with the peleng 8mm f/3.5

and it’s still plenty-wide.  The grill belongs to the Primo’s Parilla truck in Emeryville.

I think I took this photo near f/3.5, but I don’t remember.  Sharpness is pretty much the same across the entire image, since the sensor is already only capturing part of the image circle.  I’ll post 100% crops anyways:

primo's parilla panasonic gf1/peleng 8mm f/3.5 - center crop

There’s some standard sharpening and so on in lightroom.

here’s a corner crop:

primo's parilla panasonic gf1/peleng 8mm f/3.5 - corner crop

and I’ll throw in a shot with the peleng on a 5D Mark I for crop-factor comparison:

peleng 8mm f/3.5 on a 5D mkI

conclusion:

The 8mm computar lens isn’t very useful at all, but it was fun to play with.  The peleng on the GF1 is a pretty interesting combination with fisheye distortion, a wide field of view and sort of cumbersome handling.  The image quality looks fine to me.

peleng 8mm f/3.5 on a 5D mkI
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