Canon 5D markII vs Panasonic GH2 rolling shutter ocmparison by Mike Kobal.
Steve Huff tested the new SLRmagic 26mm f/1.4 lens on the Olympus E-PL1. Reminder: You can buy them on [shoplink 18603]eBay only (Click here)[/shoplink].
Photographyblog reviewed the [shoplink 14822]Panasonic 7-14mm F4.0[/shoplink] Lens. The lens gets highly recommended and not highly recommended mainly because of the high price tag (the performance itself is very good!). But at least in US this is changing quickly. There has been a $150-$200 price drop at Amazon, Adorama and BHphoto.
18 Responses
I don’t really get it, what is this comparison supposed to show?
I’m pleased it’s not just me then. I couldn’t see what it was supposed to be telling me either. I expect the video users will tell us soon enough. I only take stills with my GH2 and I find the quality superb. Not at all interested in full frame Canon or Nikon – way too big and heavy for me.
Go to the YouTube and activate 720 HD resolution + full screen. (Make sure that your Flash has video acceleration.) Then the difference becomes more pronounced: 5D2 has at some panning speeds rolling shutter effect while GH2 doesn’t.
Both cameras (and many others) use a sensor design that reads the sensor from top to bottom for each frame, so if you pan the camera sideways, depending on the speed of the pan things will look tilted, if the panning speed is slow you wont notice it but if you pause the video when he is panning quickly you will see that buildings are not straight but tilted.
> The lens gets highly recommended and not highly recomemnded […]
Admin, you should probably start using a browser which has spell checker and … take more breaks 😉
I suppose the line should read:
“The lens gets recommended and not highly recommended […]”
That happens because I am writing most of the text on my iPhone 🙁
Try a Galaxy Tab sometime. 🙂 Ok, ok, an iPad too. 🙂
Its the rolling shutter effect…. as titled..
What you are looking for is the amount of distortion (skewing) of vertical lines when panning….
at the end of the video it goes jerky – this is to let you compair the verticls of both cams…
But as expected they are both the same – so much bull about this effect – if a cam takes 1/30th sec to read the top of sensor to the bottom then the degree of distortion of verticals will be the same – no matter if its GH2, GF1, 7D, 5D – whatever if it takes 1/30th sec it takes 1/30th sec – no cam will be better than any other with regards to this effect UNLESS the whole image is read at one moment (which currently no video SLR cam is doing)….. to reduce this effect of skewing increase the shutter speed (at 1/1000th sec the amount of movement apparent between reading top of frame and bottom of frame will be negligable)!
What I do notice is there seems much better contrast and detail on the GH2!!! – but the rolling shutter will always be the same – soooo much bull about this effect being better on the GH1/2 than anyother cam!
Jim is right, there is no difference between each camera, because it doesn’t matter. It’s how the sensor is designed to capture video frames. If you look at the comparison, you “might” see a slight difference such as the GH2 being able to handle the skew a tiny bit better (?) than the 5D. But the difference is so slight that it is negligible. If the camera uses this type of sensor, then you will have rolling shutter issues. Unless they redesign the sensor to be a global shutter, or figure out a way to take full frame images for each frame with the existing sensor, then that will be a breakthrough in dealing with the panning/capturing fast horizontal motion problem of this specific technology.
In the meantime, as Jim states, shoot with a faster shutter speed, although this requires alot more light. If increasing the light output is not an option, there are some plugins available for post production workflows that can help with this problem.
Galaxy tab has Swype, which is about 1000 faster than the hunt & peck an iPad forces you to use (minus a BT keyboard, of course!)
Admin,
Detailed Hungarian review about GH2 on Pixinfo:
http://pixinfo.com/cikkek/panasonic_lumix_dmc-gh2
Thanks!
The rolling shutter issue is easy.
Any CMOS with a rolling shutter at a given shutter speed will have the EXACT same skew. Think about it.
Any CMOS with a 1/60 second shutter at 1080 lines. Each line takes 1/64,800 of a second to scan. Each line is 1/64,800 sec apart. Depending on the speed of the pan (focal length) During that fraction of a second the camera field of view moves X distance on the sensor.
A higher shutter speed will yield less skew.
Unless the sensor collects the lines say interlaced, or scanned multiple lines at a time, the skew should be identical.
I don’t agree with you, Max. The degree of rolling shutter artifacts are not depending on the shutter speed. It is relative to the speed of the rolling shutter, i.e., the shutter curtain in a mechanical implementation. Since we are talking about electronic implementation here, it is depending on the speed of the sequential sensor readout. This is typically independent on the actual shutter speed.
I have illustrated this here:
http://m43photo.blogspot.com/2010/12/gh1-vs-gh2-rolling-shutter-evaluation.html
M43photo…
I dissagree with you findings – in your test you conclude the GH1 has a 185pixel gap and the GH2 a 193 pixel gap – if you had used a higher shutter on the GH1 (i.e. 1/1000 to match the GH2) then the blur would be less and the pixel distance slighly more – they would be exactly the same! – which is what I would expect…
What I do find perplexing is that the effect seems to be identicle at any shutter speed? – you have the same amount of skew on 3 shots from 1/500 to 1/2000…. strange – I dont know how this is occuring?
Try a test with differing video frame rates and a fixed shutter speed… i.e. 24fps, 25fps, 30fps….(can the GH2 do very low (3fps) video frame rates (I thought I remember seeing that it could go down to very very slow FPS?) Dont know for shaw, but this might yeild some insight?
PLEASE IF ANYONE KNOWS HOW THIS EFFECT IS IDENTICAL IN APPEARENCE WITH DIFFERING SHUTTER SPEEDS – EXPLAIN HEAR! – VERY INTRESTED!
@jin: I explained why the rolling shutter effect is unrelated to the shutter speed in the post just above yours.
@M43photo
Yes you said it was the read speed but please explain this… How does read speed over ride shutter speed with regard to this effect/artifact?
The GH2 has a 2x sensor read speed over the GH1 so why is the effect not halfed? – Also how is it the shutter speed does not effect the read speed? How can the image when read in 1/1000th sec be as distorted as an image that has taken 1sec to expose? shawly motion diffrences in a shorter shutter speed will be less?
I wonder if your leggo thing was spinning at a kind of temprol niquest frequency, moving into the old wheel goes backwards effect territory and hence keeping the skew? dunno thats why I wanted it explained. (maybe try your leggo again at slower rotaion speed – it does not need to be very fast, just fast enough?)…
I agree you seem to have shown that shutter speed has no effect.. but i’m totaly puzzled by this 🙂
p.s. Very much like the little leggo moving focus target you made – nice work! (again tho move it a little slower, and you might get the gh2 keeping it in focus – try to find the max speed each cam can follow focus then compair… your current one does represent a fairly fast target for most video)… keep up the good work!
Two ugly beasts. Jellyvision-a-gogo.