GH1 vs. camcorder, bitrate, aperture

T

tcglog

Active member
Hi! My first post, a few questions.. still feel free to contribute!

1) I understand that to use the GH1 as a "family camcorder" the aperture should be about 2 stops smaller than max. (at least for the 14-140) to get a larger dof. That means I have to up the ISO by 2 stops. My question is does the GH1 have a 2 stop advantage over a 1000$ camcorder or will this setup with the GH1 result in a noisier image than with the camcorder?


2) About the bitrate, here is an image comparing the GH1 with the JVC Everio GZ X900E camcorder:
http://www.tekniikanmaailma.fi/s/f/editor/Panasonic%20GH1%20kaavio%201.pdf

How do I read from this chart to get Mbit/s? Should I look at the red or blue bars? I tried dividing the value for the blue bars with 8 and for the JVC got approx 24 which would go with the fact that it uses 24Mbit/s, but for the GH1 I get about 9, so I wonder if I did it wrong?


3) Also I read that camcorders use different AVCHD than the GH1, is that the different codec or what? Why does the GH1 need really high Mbit/s to get a good picture when camcorders use max. 24Mbit/s? How come the Canon 5DmkII uses as high bitrates as 40?


Thanks for replys!!
 
Last edited:
AVCHD have many different levels , so on example "base profile" with higher bitrate not will be better than "High Profile" with significantly lower bitrate.

canon use Base Profile@5.0
panasonic use High Profile@4.0

Base Profile and High Profile usage:
Baseline Profile (BP)Primarily for low-cost applications that require additional data loss robustness, this profile is used in some videoconferencing and mobile applications. This profile includes all features that are supported in the Constrained Baseline Profile, plus three additional features that can be used for loss robustness (or for other purposes such as low-delay multi-point video stream compositing). The importance of this profile has faded somewhat since the definition of the Constrained Baseline Profile in 2009. All Constrained Baseline Profile bitstreams are also considered to be Baseline Profile bitstreams, as these two profiles share the same profile identifier code value.

High Profile (HiP)The primary profile for broadcast and disc storage applications, particularly for high-definition television applications (for example, this is the profile adopted by the Blu-ray Disc storage format and the DVB HDTV broadcast service).
Click to expand...


about DOF, stops, and comparision to "Some Anything" = RTFM, and optics may be compared separatelly, if you have take a look to current consumer camcorder - can see there optics is described, it not changeable, but quite "fast" = mainly F1,2-1,8 used.
 
Last edited:
If you're using the GH1 as a family camcorder.... seriously just through it into ia mode....
It's not meant to shoot the way a camcorder shoots... too many things to futz with...
 
DaLiV said:
AVCHD have many different levels , so on example "base profile" with higher bitrate not will be better than "High Profile" with significantly lower bitrate.

canon use Base Profile@5.0
panasonic use High Profile@4.0

Base Profile and High Profile usage:
Click to expand...

Thanks for your reply! So that is why Canon has to use higher bit rates.

Also, do you mean the GH1 uses the same AVCHD as Panasonic camcorders only with 24Mb/s changed to 17Mb/s ??

about DOF, stops, and comparision to "Some Anything" = RTFM, and optics may be compared separatelly, if you have take a look to current consumer camcorder - can see there optics is described, it not changeable, but quite "fast" = mainly F1,2-1,8 used.
Click to expand...
Ok, I understand the optics and the sensor work together but I'm still not sure whether the GH1 with a small aperture would perform as good as a camcorder?
 
Blackout said:
If you're using the GH1 as a family camcorder.... seriously just through it into ia mode....
It's not meant to shoot the way a camcorder shoots... too many things to futz with...
Click to expand...

Thanks for your reply! What does the iA mode do?

I don't have a GH1 yet, getting it depends on a few things like the small-aperture performance against a camcorder with big dof. Any insight on that?
 
I'm still waiting for answers to questions 1) and 2) and hope someone would be able to provide help.

So far I got question 3) almost answered but still need to know if the only difference to Pana camcorders is the bit rate?
 
I don't think your first question makes sense. The aperture setting which affects depth of field depends on lighting conditions. If you are outdoors in bright sunlight then you usually use a small aperture which would create a large depth of field. If you are indoors then you would have the aperture wide open which would create a narrow depth of field which most people would consider a good thing since your subject can be in focus with the background out of focus.

I don't think the GH1 makes sense to use solely as a 'family camcorder' since the autofocus is too slow and any changes in aperture while recording are more noticeable than a traditional camcorder. In short if you leave everything on automatic it won't work as well as a camcorder set to auto.
 
climber said:
I don't think your first question makes sense. The aperture setting which affects depth of field depends on lighting conditions. If you are outdoors in bright sunlight then you usually use a small aperture which would create a large depth of field. If you are indoors then you would have the aperture wide open which would create a narrow depth of field which most people would consider a good thing since your subject can be in focus with the background out of focus.

I don't think the GH1 makes sense to use solely as a 'family camcorder' since the autofocus is too slow and any changes in aperture while recording are more noticeable than a traditional camcorder. In short if you leave everything on automatic it won't work as well as a camcorder set to auto.
Click to expand...

When did I say I would use it "solely as a family camcorder" ? I plan on using it for many other projects as well where I need the manual capabilities and dof properties.

I'll try to explain again: if I shoot video inside in mediocre brightness AND want to use a large depth of field I can:
a) use a camcorder with its max. aperture since the dof is always deep because of the small sensor, or
b) use the GH1 with a smaller than max. aperture (e.g. 2 stops) and bump up the ISO accordingly (2 stops).
Now, does this 2 stop increase of the GH1 ISO result in a noisier image than with the camcorder? Or does the larger sensor and optics of the GH1 have a noise advantage that is at least 2 stops hence making it as noisy or less noisy than the camcorder?

What is there that you don't understand?

So any help on that or the other 2 questions?

Also I thought camcorders use CDAF so why are they much better at focusing than the GH1? And regarding changes in aperture being noticeable I can always use aperture priority if it is disturbing right?
 
Hi tcglog -
1. the GH1 will consistently outperform any camcorder when it comes to low light performance. I have tested side by side with a Sony EX1, and it was a hard fight.

2. But autofocus with the kit lens is slower than camcorder. In fact, autofocus can be quite unreliable in my opinion, as the GH1 tends to lose focus, especially in detailed scenes and mediocre light. Also, no power zoom.

3. The GH1 with standard bitrate (17 mbps) is generally fine for 720p, but in 1080, there is mud (high detail scenes and handheld). With the latest hack, 1080 is fine as well.

4. The biggest problem with GH1 is Fixed Pattern Noise - it varies in severity from camera to camera. So, please test. Set camera to 1600 iso, under-expose to -1, -2 and -3. Point the camera to flat white/cream surface. The good news is that for most cases, it lessens considerably after about 3 days to one week of usage. For others (like me) we tried "burn in" process, and it generally worked. And there are some that say nothing works for them - they still have it.

Hope this helps!
 
I sold my Sony HDR-SR11 when I got the GH1 and once the hack solved the pulldown issue, I've never looked back. The only feature I miss on the Sony was the power zoom, but I think I used it too much anyway, so it's really not a loss. With the GH1, I have a MUCH better still camera and a video camera that is noticably better IMHO for home video.

Now, with the hack, there is no comparison. I plan on getting the 20mm F1.7 Panny lense which so help with indoor shots.

Color me happy!
 
jamesjjs said:
Hi tcglog -
1. the GH1 will consistently outperform any camcorder when it comes to low light performance. I have tested side by side with a Sony EX1, and it was a hard fight.
Click to expand...

Thanks for your reply James!

That sounds great, and kind of answers the question.

2. But autofocus with the kit lens is slower than camcorder. In fact, autofocus can be quite unreliable in my opinion, as the GH1 tends to lose focus, especially in detailed scenes and mediocre light. Also, no power zoom.
Click to expand...
Yeah the lack of power zoom is one thing I would probably miss on the GH1, I'm glad it has a 10x zoom though. I hope they improve the autofocus for the GH2. Do you mean the autofocus is worse with the same dof or does the GH1 autofocus only seem worse because of the small dof?

3. The GH1 with standard bitrate (17 mbps) is generally fine for 720p, but in 1080, there is mud (high detail scenes and handheld). With the latest hack, 1080 is fine as well.
Click to expand...
Ok, I guess 720p would be good enough for most situations anyway. Again let's hope they use higher bitrate and better coding with the GH2..

4. The biggest problem with GH1 is Fixed Pattern Noise - it varies in severity from camera to camera. So, please test. Set camera to 1600 iso, under-expose to -1, -2 and -3. Point the camera to flat white/cream surface. The good news is that for most cases, it lessens considerably after about 3 days to one week of usage. For others (like me) we tried "burn in" process, and it generally worked. And there are some that say nothing works for them - they still have it.
Click to expand...
Is this the banding issue? I read someone got it right by dust-cleaning the sensor multiple times. That's a weird problem but I'm sure it can be disturbing..

Hope this helps!
Click to expand...
Sure did, thanks again for your help James :)
 
Phil Seastrand said:
I sold my Sony HDR-SR11 when I got the GH1 and once the hack solved the pulldown issue, I've never looked back. The only feature I miss on the Sony was the power zoom, but I think I used it too much anyway, so it's really not a loss. With the GH1, I have a MUCH better still camera and a video camera that is noticably better IMHO for home video.

Now, with the hack, there is no comparison. I plan on getting the 20mm F1.7 Panny lense which so help with indoor shots.

Color me happy!
Click to expand...

Thanks for the info Phil!

I'm glad to hear you never looked back. I'm already pretty sure the GH1 has enough to be good enough for more creative use, but using it for home video is also important.

I understand the pulldown is an issue only in NTSC cameras? I would use PAL so I guess I wouldn't have to worry about that.

The power zoom would indeed be very nice to have but I understand you can't quite have it all.. so it's a minor defect if everything else is as it should.

Are you going to use the 20mm for video as well? Do you think the lack of IS is important?

Thanks again!
 
hi guys, just thought i'd add 2c,
I had the kit lens, and low light was not that great.... but it wasnt any worse than my JVC GY HM100.
From info on here I got the Panny 20mm, it is nice, low light was better, auto focus was a bit sketchy, it doesnt seem to know what to focus on, still, Im trying to always manual focus anyway.
But then..... I saw a Canon FD 50mm f1,4 on ebay and thought, what the heck, and placed a bid and didnt think any more about it,
I won it! $61.00. grabbed an adaptor for $20. they arrived on the same day, the Panny 20mm hasnt been out of the box since.
It is just so much better, its crisper, its brighter in low light, the manual focus is so easy to use.
Only now do I really think I could turn out some video footage that might look pro.
Only downside is it isnt very wide, Im now looking for 30mm Sigma f1.4....
any other suggestions for a wide fast lens most appreciated.
 
jedman1 said:
Im now looking for 30mm Sigma f1.4....
any other suggestions for a wide fast lens most appreciated.
Click to expand...

If you can find one, the Panasonic 25mm f/1.4 Leica D Summilux is a very nice 4/3 lens which allows for aperture control and AFS on the GH1 when used with the DMW-MA1 adapter. Manual focus is fast and smooth. Bokeh is also sweet. But it's not inexpensive.
 
thanks for replying, that lens does sound nice, just a little out of my price range though .
Maybe secondhand, cant find one ATM though.
 
jedman1 said:
any other suggestions for a wide fast lens most appreciated.
Click to expand...

Since you are already have a Canon FD adapter why not get the 35mm f/2.0, 24mm f/2.0 and the 20mm f/2.8. I got those and love them, especially the 35mm. Also got a FD 85mm f/1.8 and a 100mm f/2.8 for a pretty versatile prime lens set basically covering the entire focal range I need. All for just a bit more than that Sigma 30mm.
 
You must log in or register to reply here.
Back
Top