E-PM2: Ojito Wilderness

junk1 wrote:

Nice shots. The PM2 tempts me. It's hard to find real world info because it did not sell well.

I need a light camera to put on my R/C airplane (currently using an aging Fuji F20). The GM1/GM5 have the super slow shutter limitation, otherwise they are ideal (their built in time-lapse mode is ideal).

The GM-series cameras can be set to full-time electronic shutter mode, allowing shutter speeds from bulb up to 1/16,000. This also completely does away with mechanical shutter wear. Its shutter mechanism, being electronic first curtain anyway, is immune to shutter shock (which I'd imagine could be a greater issue on a flying platform for the same reasons shutter shock is typically worse handheld than on tripod).

The limitation of the GM's electronic shutter is that you could see motion "jello" artifacts under certain circumstances (it takes 1/25 sec for the rolling electronic shutter to scan the entire sensor), and RAWs are limited to 10 bits in electronic shutter mode which enables by default at any shutter speed beyond 1/500 (10 bit RAW is a fourfold reduction in bit depth from a 12 bit RAW, but still four times better than 8 bit JPEG). I'm not keen on the GM series at all for my own use in landscape and in studio...but they seem like the most ideal MFT cameras for hobbyist aviation purposes (and far better for the otherwise shutter-destroying activity that is timelapse).

How fast does the PM2 shoot images in raw mode (continuously)? I only need around 1FPS (1 frame every 2 seconds with my Fuji has been pretty much ideal).

I'd say it will capture RAWs continuously to about 2 fps. I tried 3 fps and it slows down after about a minute of shooting, but at 2fps it went on til the card filled up. That's with an 8GB Sandisk Extreme Pro 95 MB/sec card (which I've measured at 72 MB/sec write speed using BlackMagic Disk Speed Test on my Mac mini's built in SD slot, which is UHS-1 compatible and hooked up to the computer's PCI bus). This implies that whatever limitation I ran into is in the camera's buffer.

If I use a slow card, would that slow down the rate to 1 or 2FPS?

Cheaping out on the card isn't a good idea for what you want to do. A class 10 card mandates a minimum of 10mb/sec write speed at all times, but otherwise published SD card specs are so fuzzy that you can't determine real-world performance short of testing it yourself. Class 10 wouldn't even be enough to manage 1fps from the E-PM2, whose RAWs average around 15mb. I also have Sony UHS-1 cards in the 40mb/sec class which meet that specification in read speed, but don't do any better than class 10 cards for write speed...so you have to be very careful what you get.

10 bit RAWs from the GM series should be smaller in terms of file size, but someone else would have to report on the exact file sizes produced by that camera. A 16.1 megapixel sensor that yields 12 bits per pixel would produce, uncompressed, 24.15 MB files; a 16 megapixel sensor that yields 10 bits per pixel would produce, uncompressed, 20 MB files. Assuming the same compression ratio leading to about 15mb average for the 12 bit, the 10 bit system should produce something like 12.4mb files...still too much for 1fps.

BlackMagic actually makes a piece of free software for Mac, called BlackMagic Disk Speed Test, which you can use to check read/write speeds for any volume, including an SD card. Similar software should also exist for Windows.

Modern camera shoot much faster than I need/want - That's why being able to set the frame rate via time-lapse mode (with an unlimited number of shots) would be handy. I could add an external time-lapse timer tot he PM2, but that adds a few ounces. Would prefer to simply hold the shutter down with rubber bands basically, and shoot in continuous mode, as I do now.

I'll definitely go with the 2oz Panasonic 14mm F2.5 lens...well, unless I get a GM1 with the almost-as-light 12-32mm lens.

The GM1 weighs about 2 oz less than the E-PM2, also.