GH3 Gh2/gh3 etc

[flinty]

On another site i read where someone asked if the GH3 would have lossless ETC like the GH2,some who i agree with said the GH2s ETC was not lossless others said it was,it will be interesting how the GH3s ETC compares,i have never found ETC lossless,it adds noise and loss of resolution,noise depending on the ISO,this has been discussed before i know and its more a question regarding the GH3.
http://www.youtube.com/watch?v=rje_9Dzta-k

 

[Fresno Bob]

Can't you add this to one of the other GH3 threads?

 

[flinty]

They tend to get ignored in the post,for myself etc on my GH2 is for necessities only,i wondered if the GH3s would be lossless ,the same or even worse.

 

[terra1]

the 1080p video stream is captured from the full sensor yeah? uses the first line, drops a few, uses another line, drops a few... and so on? shrinking each line down to 1920 horizontal pixels for its 1920 x 1080p export.

the 1080p ETC video stream is captured from only the center of the sensor at nearer to the export 1920 size?

id have expected the ETC mode to have the same amount of noise as the standard 1080p mode, yet also expect the ETC mode to show that noise more as your closer in on it. so technically it is lossless with no quality loss yet in practice there is. if that makes sense.

this is my understanding how the ETC works, i could be way off tho so if i am, please somebody correct this

i only had a GH1 and was jealous of that ETC mode looking forward to getting it at last! its a nice freebie!

 

[flinty]

the 1080p video stream is captured from the full sensor yeah? uses the first line, drops a few, uses another line, drops a few... and so on? shrinking each line down to 1920 horizontal pixels for its 1920 x 1080p export.

the 1080p ETC video stream is captured from only the center of the sensor at nearer to the export 1920 size?

id have expected the ETC mode to have the same amount of noise as the standard 1080p mode, yet also expect the ETC mode to show that noise more as your closer in on it. so technically it is lossless with no quality loss yet in practice there is. if that makes sense.

this is my understanding how the ETC works, i could be way off tho so if i am, please somebody correct this

i only had a GH1 and was jealous of that ETC mode looking forward to getting it at last! its a nice freebie!

Ok thanks for the thoughts,on a lens with a not long focal lenght its useable just for me, but on long lenses like the 45-200mm the ETC pq at anywhere near full zoom is soft and mushy.

 

[stoneinapond]

....on long lenses like the 45-200mm the ETC pq at anywhere near full zoom is soft and mushy.

That lens is generally soft at its extreme zoom range. ETC mode will only add to that softness (you are afterall "magnifying" the image). The lens is really nice, especially for its present price, but as you have already observed, care needs to be taken when zooming flat out.

 

[c3hammer]

Flinty, I think you are just seeing the limitation of your lenses. When you capture three times the data through the same molecules of lens you are easily going to bring out the inadequacy of the lenses. There is also a significant accutance difference between ETC on and off. This being the micro contrast / perceived sharpnes between the two. Whether this is due to lens, image processing with ETC off or a combination of the two I can't say for sure.

While I don't have a GH2, I have used a T3i with it's crop zoom function and lens quality is paramount to image quality.

I think if you try some super high end glass you might find the image quality, while slightly different with ETC on to become much closer in perceived quality.

I'm really looking forward to giving the GH3 a whirl with my Nikkor AIS 600mm ED. That lens has proven to be incredible with the crop zoom on the T3i. I can't imaging how unbeivable it might be on the GH3.

Cheers,
Pete

 

[M. Gilden]

Ok thanks for the thoughts,on a lens with a not long focal lenght its useable just for me, but on long lenses like the 45-200mm the ETC pq at anywhere near full zoom is soft and mushy.

Understand that this is likely due to the lens, and not ETC mode.

If you have ever gone pixel peeping with still photos, you may have noticed the pictures can look nice and sharp when zoomed all the way out but when viewing at 100%, you see a different story. Up close is when you can tell how soft a lens really is.

When viewing regular 1080p video on the GH2, it is taking that larger, sharper looking frame and scaling it down to about 2Mpixel to fit (BTW: terra1 says it skips the lines in between- that is true of Canon, and why we get moire and aliasing. The Panasonic method involves more actual resampling of the image, and not just ignoring large portions of data).
However, when you shoot in ETC mode, you are not resampling at all anymore but rather recording from the inner 1920x1080 array of pixels off the sensor. That is akin to zooming in 100% on a still, and why the image seems softer.

That also explains why you may notice more noise at higher ISO- when resampling the image down to 1080p, the noisy pixels get averaged together. But when viewing the actual pixels off the sensor at 100%, there is no averaging being done so you are actually seeing the authentic gain noise.

If anything, one could argue that ETC mode is the only way to see the real authentic picture quality of your sensor and lens.


EDIT: looks like most of you beat me to the punch!

 

[terra1]

(BTW: terra1 says it skips the lines in between- that is true of Canon, and why we get moire and aliasing. The Panasonic method involves more actual resampling of the image, and not just ignoring large portions of data).

thanks for correcting my error & the far superior explanation

 

[flinty]

How can this be anything to do with the limitations of my lenses 14-140 & 45-200 are my longest micro ones,they are as sharp as any previous non micro lens i have owned and sold in the past,the 200mm at full zoom plus ETC is equivalent to 1040mm 35mm which is not that long for video,i have a FZ150 that is 600mm max zoom its 1.3x i zoom is lossless and with a 1.7x extender is 1326mm and lossless for video,i know use you will say then, but its not as good for normal video,
In the test i showed useing a wider angle 14-42 lens the loss of etc resolution is way down,and viewing on a hd tv shows far easier than vimeo,so i have to say for me etc is poo on my GH2 and only time will reveal how the GH3 compares,but most seem fine with the GH2s function.
Thanks for all the input and explanations.

 

[Thomas Smet]

You have to kind of think of the GH2 as basically a 4k camera when it records in normal mode. The sensor is 4k and the image you get from different lenses will have different levels of sharpness at that 4k. the 4k sensor of course gets down converted to 1080p which hides a lot of noise and imperfections in the quality of glass. Anytime you shoot 4k with a high level of noise and then downscale to 1080p you will basically hide that noise so you no longer notice it as much. Same thing with the lack of detail on cheaper lenses. A so so lens at 4k down converted to 1080p will end up looking pretty good.

Because ETC only uses the middle 1080p portion of the sensor you loose that down converting advantage. A soft lens that normally looks decent will now look soft. A rather clean ISO level will now look noisier because the noise no longer gets hidden due to down converting.

A sharp lens like the 20mm f1.7 looks great with ETC basically turning it into a slightly softer 52mm. It will always be slightly softer since again you no longer have the advantage of taking a 4k sensor and down converting.

Basically the ETC mode functions exactly like a native single 1/2" 1920x1080 CMOS sensor video camera.

Could ETC on the GH3 be better? Perhaps. If the native resolving power of the 4k sensor on the GH3 is better then yes the middle 1920x1080 may look sharper and more detailed then on the GH2. Since the noise may be lower on the GH3 this may also translate to better noise handling in ETC mode as well.

 

[c3hammer]

How can this be anything to do with the limitations of my lenses...

Look at it this way. The glass structure is not capible of resolving 1920x1080 in that area of the lens. As an extreme example, it's like looking through a jar of marbles relative to a jar of water. The processing of the bayer pattern down to 1920x1080 from 4k as Thomas put it, is where they are getting those lenses to look so sharp. The sharpness is digitally created by lens profiles in camera. When you go to ETC it simply can't resolve the same level of detail.

Try your ETC on and off with a high quality, known vintage lens like a Zuiko 50 f/1.4 or a Nikkor AIS 85mm f/2.0 at f/5.6 and post your comparison. I think you'll find your lumix lenses to be less than desireable.

Cheers,
Pete

 

[flinty]

Ok i am tired of people saying the 14-140 is not sharp,mine can take stills at wide and zoom and give incredible resolution as good if not better than my rarely used 20mm,i just fail to see how a Niktor can be sharper on video which is low resolution,i dont own one so cant do a comparison,for me the 14-140 is a great sharp lens and a fixed 50mm Niktor would be of no use to me personaly,i guess the satisfaction of losing no quality on a cheap cameras albeit only 1.3X i zoom does not help.
Thanks for the explanations on lenses etc but imo the 14-140 is not a soft lens.

 

[Thomas Smet]

Every single lens on the planet handles detail in a different way. Zooms tend to not resolve as much as primes. It is a very subtle amount typically and typically only noticeable when comparing side by side. The fact is that it is there if you know what to look for. Of course we are not talking about a quality fact so much as we are talking about an esthetic quality judgment. Some people such as myself don't mind slightly lower quality glass for even stills. Other people are more gung-ho about it.

If you search the web for lens reviews you will see how different lenses resolve acutance at various levels. This has nothing to do with pixels or resolution but the clarity of the glass. ETC quickly shows off the build quality of a lens. I do agree the 14-140 is a darn good lens but it is not perfect and typically a prime will be superior to a zoom. Lots of stuff has to take place in a zoom and it is very hard and expensive to make them resolve as much as a prime.

 

[M. Gilden]

Try your ETC on and off with a high quality, known vintage lens like a Zuiko 50 f/1.4 or a Nikkor AIS 85mm f/2.0 at f/5.6 and post your comparison. I think you'll find your lumix lenses to be less than desireable.

^ This.

Sorry if you're getting tired of us calling the 14-140 "not sharp", flinty. But our experience and understanding of the technical detail disagrees with you.

 

[flinty]

^ This.

Sorry if you're getting tired of us calling the 14-140 "not sharp", flinty. But our experience and understanding of the technical detail disagrees with you.

It is sharp,if the lens can take very high resolution photos and as sharp non etc video footage as any lens with my my GH2 the technical details may be beyond me.
What i fail to understand is the lens copes well with stills and video,ETC is the same with all lenses,obviously better on wide angle but that is little use to me.

 

[M. Gilden]

It is sharp,if the lens can take very high resolution photos and as sharp non etc video footage as any lens with my my GH2 the technical details may be beyond me.
What i fail to understand is the lens copes well with stills and video,ETC is the same with all lenses,obviously better on wide angle but that is little use to me.

The technical details make all the difference in understanding this.
Compare a still shot on a zeiss 50mm prime and your 14-140. They may look similar from far away, but zoom in on the still as far as you can go (100%) and you will immediately see why etc mode is soft with your glass. You are only using that center portion. A sharper lens will retain detail at that zoom level, and that is simply fact.

 

[flinty]

Yes i will surrender,my 20mm must be a poor lens as well because ETC is no better with it,for long range work nature etc my lossless 1326mm total including i zoom FZ150 will suffice.For me ETC is one of the two things i dislike with my GH2,a great camera never the less.

 

[M. Gilden]

Yes i will surrender,my 20mm must be a poor lens as well because ETC is no better with it,for long range work nature etc my lossless 1326mm total including i zoom FZ150 will suffice.For me ETC is one of the two things i dislike with my GH2,a great camera never the less.

::scratches head::
Ok. But I don't really get what you "dislike" about ETC mode, aside from perhaps not fully understanding it. If you are hoping the GH3, or any future camera will magically be better somehow, I have some sorry news for you. This is just how optics work.

 

[flinty]

::scratches head::
Ok. But I don't really get what you "dislike" about ETC mode, aside from perhaps not fully understanding it. If you are hoping the GH3, or any future camera will magically be better somehow, I have some sorry news for you. This is just how optics work.

Ok to close this thread i admit i dont understand why ETC will not get me resonably sharp close ups of distant objects which is all it would be any use for.My GH2 has more resolution than my FZ150 but cant match its resolution in ETC mode http://www.youtube.com/watch?v=GGVqkvnJqnY
Shows FZ150 shots with normal 24X/i Zoom & 1.7 add on lens,ETCs 2.6 against i Z00m 1.3 is more for the sensor to cope with i suppose.