Does the GH1 line-skip or pixel-bin?

P

Pietro Impagliazzo

Well-known member
Does the GH1 line-skip or pixel-bine to achieve HD resolution from its sensor?

Are there any DSLRs in the market that DO NOT line skip?

Thank you a lot in advance.

:happy:
 
It does clearly not line-skip, my guess is that it does some kind of bilinear interpolation or similar but there is no official statement about it.
 
Nobody outside of Panasonic engineering in Japan knows the answer. Anybody who definitively says "it pixel bins" or "it line skips" does not know what they're talking about.

With that said, the one thing that seems reasonable to assume is that it's doing *something* like that, because it's using a still-camera sensor, and those aren't made for full-frame-rate video. But exactly what it's doing, we don't know.

All DSLRs must employ similar techniques, or at least comparable techniques. They have to reduce the data they're reading, because they cannot possibly read all the information the chip is storing, at video frame rates.

The GH1's method is quite a bit superior to the way the Canons do it, in that you will see far fewer observable artifacts (primarily the rainbow purple/orange moire that the Canons exhibit, or the extreme aliasing that the Canons get in 720p). But it isn't on par with what the Red does, or a dedicated full-raster video camera. Red, and video cameras, sample their entire sensors.
 
Just ask Vitaliy Kiselev whether he's willing to search the appropriate scaling algorithm in the firmware ;)
 
Well, being better than the Canon and not presenting rainbow moire is a nice thing already.

Now just need to get some jello comparisons... I'll try Vimeo.

If you guys compared them beforehand, which has less jello?

Barry... Well, Scarlet is my top plan, unfortunately one that I cannot execute now.

Gotta go with a DSLR for now, and the last step will be figuring out a good budget zoom lens for the GH1, but that's for another topic.

Thank you all for the answers.
 
Before this hack... I would say the cameras were equal, with each one winning in certain areas... after this hack that raises the bitrate up to 50 mbps and gives native 24p, I am now confident the GH1 smashes the 7D and has even an edge over the 5D mkII.
 
Pietro Impagliazzo said:
If you guys compared them beforehand, which has less jello?
Click to expand...
GH1 and 7D are pretty much identical in rolling shutter. Don't know about the 550d/t2i.

Gotta go with a DSLR for now, and the last step will be figuring out a good budget zoom lens for the GH1, but that's for another topic.
Click to expand...
The kit lens for the GH1 is pretty fantastic; only thing about it is a slow maximum aperture opening, but other than that it's great.
 
Blackout said:
Before this hack... I would say the cameras were equal, with each one winning in certain areas... after this hack that raises the bitrate up to 50 mbps and gives native 24p, I am now confident the GH1 smashes the 7D and has even an edge over the 5D mkII.
Click to expand...
I pretty much agree, with the caveat that the 7D does at least two things better than the GH13 - it can do live monitor output during recording, and it has higher selectable ISO values.
 
The monitor being the most key for me in terms of narrative filmmaking. But I'm enjoying the better quality out of the camera. I know I'll be glad to shoot this run and gun doc with better video.
 
I wonder why they have not made a interchangeable lens camera that will us the center 1920x1080 pixels of the sensor to capture video? Then the camera would have 1:1 pixel mapping and it would not have to do any scaling at all.

Now I fully understand that this would change the perspective. However, I see that as a benefit. You could introduce the first Interchangeable lens camera with an auto zoom function. Basically, when you want a wide angle you could use the whole sensor. That would give you a shallower depth of field and it would require scaling to get it down to 1920x1080.

Then as you zoom in it would just reduce the number of sensor pixels that it uses to extend the focal length. When you reached 1920x1080 you would have 1:1 pixel mapping and an ideal image.

Doing this could turn the 20mm F1.7 pancake lens into a 20mm-120mm F1.7(In terms of light capturing and not DOF). That is if you are going from a 12 megapixel native sensor to the 2 megapixels of 1080p. I would pay at least $2500 for a camera that could do that.
 
Pietro Impagliazzo said:
The RED does that and as you can see there are lot of factors that need to be optimized for full frame res.

Like OLPF and such.

___

What you guys have to say about this list:
http://www.bhphotovideo.com/wl/355170D141

Any word on SDHC cards?
Any other vital acessory?
Click to expand...

Yea I am wondering if the RED technology could be introduced in a reasonably priced camera. The RED won't auto zoom for video though, right?

I have heard that the GH1 can be had new for under $1000 now. With the new firmware mod I was able to get a $16 third party battery to work with my GF1. I bought an 8 GB 30 GB/sec Sandisk SD card on amazon for about $50.

That sounds like the ideal package to me. However, I would probably just by the GH1 body only since I am not too fond of the 14-140mm lens. It is just too slow and expensive for my tastes.
 
woah, does the GH13 not have monitoring output during recording?

Also, how is the moire/aliasing compared to the 7D?
 
No the GH1(3) does not have monitor-out during recording. (Yet. Perhaps it will, perhaps not.)

And having shot quite a bit with the 5DII, the 7D, the T2i and the GH1(3), I can confidently say that moire and aliasing are much worse with the Canon cameras than the Panasonic. I've had shots ruined by the technicolor-moire of the 7D. While the GH1(3) does have aliasing, it doesn't have the rainbow effect and is less noticeable.
 
hmm, interesting. But without a live monitoring out during recording it's going to be useless for my applications. common panasonic, let's get a move on! :)
 
Thank you all again.

Just clearing something up:

Was there an official firmware from Panasonic that introduced higher data rates within AVCHD in 1080p? Did I get this wrong?
 
You must log in or register to reply here.
Back
Top