EOSHD.com reader RichST who picked up a Japanese GH2 this week (production retail model) has been showing me some useful shots demonstrating the look of different picture profiles on the GH2, including the new Teleconverter mode. Seemingly Panasonic listened, because this is a feature the community has long been dreaming of. No line skipping, no pixel binning, no scaling – just the ability to take an unscaled 1080p 1:1 crop of the centre of the sensor.
Labeled Teleconverter Mode, for the first time we have a 1:1 feed off the sensor, unscaled and therefore with minimal artefacts.
Noise is slightly higher since it’s not scaling the full 18MP sensor to 1080p or applying much in the way of image processing. But the image is detailed and in true 1080p resolution.
Why is this so handy?
Imagine a 1920 x 1080 sized cut out in the middle of a 4976 x 2800 box (that’s in native 16:9 mode) as illustrated above.
The feature is so useful because it allows us a clean way to avoid vignetting on c-mount lenses designed for 16mm, 8mm or small chip ENG video cameras. There are some very high quality lenses which do not cover the Panasonic GH2’s full sensor.
The GH1 featured a ‘digital zoom’ mode of 2x or 4x in movie mode but this was of very low quality, with poor low resolution footage. The GH2’s is a big improvement and is truly a pixel-for-pixel window of the sensor – no line skipping, no binning.
The shot below (I have scaled it to fit the article width of 820 pixels) was made in ISO 320 I believe, in 1:1 mode. Click the link below to see it in full 1080p along with some normal 1080p full sensor frame grabs in video mode demonstrating each of the GH2’s picture profiles. They’re all frame grabs in video mode.
Richard says that the GH2 seems slightly sharper even in good light than the hacked GH1 with less ‘over-sharpening’ artefacts.
Now you can use c-mount zooms like this TV lens which is a F1.0 constant 8-48mm zoom. Fantastic versatility at F1.0!! Name me another zoom lens that fast.
I have a few c-mount zooms, including a Canon F2 I picked up for around $20 a few months ago. On the full frame of the GH1 it vignettes but it will perform admirably on the GH2. Something to look forward to…
In the mean time, keep a close eye on eBay for these kind of lenses. They’ll be great investments. Yes you do loose some shallow depth of field, but on an F1.0 lens this is an advantage as the shallow depth of field is reduced to a manageable (but still very pleasing) level.
The sensor becomes more like a 1/1.7″ chip but remember the noise level and low light performance is not hurt very much especially with fast zooms.
Also 1:1 mode is better than just cropping a 1080p video stream to remove vignetting, since you don’t loose any resolution.
UPDATE from RichST
At normal viewing distances on a 1080 TV it is hard to tell [1:1 crop mode] apart from the regular mode and I want to say has a more filmlike look to it though slightly less detail. The magnification is 2.9x if you use 1080, longer if you just need 720. I want to say that it effectively converts the camera into something like a 1/2″ sensor camera. Casual shooting today seems incrementally better than the GH1(3); they’ve done a better job of smoothing out edges while preserving detail. Higher ISO seems where the most improvement has been made. For me a 24p mode that isn’t buggy is the biggest improvement, God how I hated unwrapping that 60i wrapper. I don’t really have broadcast quality footage, just stuff I shot around the yard today, but may try and put together something, including some shots with the tele conversion.
