Tech Note Why The Panasonic Had Poor Resolution

I tested at all stops using the EIA chart.

2.8 = 630H, 730V
4.0 = 630H, 730V
5.6 = 660H, 750V
8.0 = 660H, 730V
9.6 = 670H, 700V
11 = 670 H, 620 V (oooh... not good...)
min = 600H, 540V (major not good).

So the rule is: keep it in single digits and you're okay. Hitting 11 = bad. But truly that's the same with all the HD cameras. The Canon limits the iris to 9.6 so it can't go to 11. The Sony includes a menu option to stop the autoiris from stopping down too far; you can give it a max of either 5.6 or 8. With the Panasonic it appears that anything up to 9.6 is okay, 11 is bad. For "min" -- that's the last iris tick right before the iris closes completely; I think it represents 11 + 1/3.
 
Jeskid said:
Bob,

If lower F-stops = greater resolution, would it be better to stop the camera down using the ND filters and open up the iris on a sunny day?

Jes
Click to expand...

In a word, YES!!!

Look at Barry's numbers:

2.8 = 630H, 730V
4.0 = 630H, 730V
5.6 = 660H, 750V
8.0 = 660H, 730V
9.6 = 670H, 700V
11 = 670 H, 620 V (oooh... not good...)
min = 600H, 540V (major not good).
Click to expand...

From F2.8 to F8 you get the highest resolution, but even F9.6 is still reasonable. Go to f11, and there is a drop in resolution. So, if you are shooting on a bright sunny day, use the 1/8 or 1/64 built-in ND filter to lower the F Stop to the range of F2.8 to F8. While more tests would need to be preformed to verify if this holds true for all the zoom range, for now it apopears that F2.8 to F8, even F9.6 is the sweet spot for the lens as far as resolution.


Bob Diaz
 
Luis Caffesse said:
I can see their new ad campaign now:


sony.jpg
Click to expand...
You are an Efing Genius.
 
Barry_Green said:
I tested at all stops using the EIA chart.

2.8 = 630H, 730V
4.0 = 630H, 730V
5.6 = 660H, 750V
8.0 = 660H, 730V
9.6 = 670H, 700V
11 = 670 H, 620 V (oooh... not good...)
min = 600H, 540V (major not good).

So the rule is: keep it in single digits and you're okay. Hitting 11 = bad. But truly that's the same with all the HD cameras. The Canon limits the iris to 9.6 so it can't go to 11. The Sony includes a menu option to stop the autoiris from stopping down too far; you can give it a max of either 5.6 or 8. With the Panasonic it appears that anything up to 9.6 is okay, 11 is bad. For "min" -- that's the last iris tick right before the iris closes completely; I think it represents 11 + 1/3.
Click to expand...

maybe i missed it, did you retest the HVX? cause ithought the shoot out said the HVX was peaking at ~550.
 
x2mag68 said:
You are an Efing Genius.
Click to expand...

And here I was thinking no one even noticed my photoshop masterpiece.
:thumbsup:

(not trying to derail the thread into 'jokeland' here...just couldn't let the opportunity go).
RESUME TECH TALK.
 
BobDiaz said:
In a word, YES!!!

Look at Barry's numbers:



From F2.8 to F8 you get the highest resolution, but even F9.6 is still reasonable. Go to f11, and there is a drop in resolution. So, if you are shooting on a bright sunny day, use the 1/8 or 1/64 built-in ND filter to lower the F Stop to the range of F2.8 to F8. While more tests would need to be preformed to verify if this holds true for all the zoom range, for now it apopears that F2.8 to F8, even F9.6 is the sweet spot for the lens as far as resolution.


Bob Diaz
Click to expand...
Thanks Bob!

Last question (for a technically challenged mind). Are the ND filters built into the camera the best to use to achieve this Or is glass on the front of the lense? Which one do you think impacts resolution more?

Jes
 
The internal filters should have no effect on resolution, the same with high quality glass filters, IE Schnider, Tiffen Etc. Crap filters are a diffeent story.
 
Yes you should be using a 16:9 chart. But I don't have one here. The EIA is an old chart and not of much use other than for comparing itself against itself (i.e., it's perfectly valid for seeing the difference between the same camera at f/2.8 and that same camera at f/11). Or, it's valid in that everyone else is publishing EIA shots, so if you're comparing EIA against EIA, assuming they were printed correctly and shot correctly. What I'm saying is, you can't say that the Sony got 700 lines on an EIA chart and the Canon got 600 lines on a DSC chart and then try to draw any conclusions from that. You'd have to see the same chart against the same chart.
 
I was thinking the same thing !!!!! Suddenly the resolution is well beyond 600 which is in sharp contrast to the 6 cam test performed by the same guy. Shouldn't the rez of a cam be chart independent !!!! The more I read the less I understand. Maybe I should stick with chemistry.



x2mag68 said:
maybe i missed it, did you retest the HVX? cause ithought the
shoot out said the HVX was peaking at ~550.
Click to expand...
 
People look at the chart and decise what the resolution is:) There is nothing absolute about this. You can measure the chart in a Matlab app or you can use other software to do it. This will be more precise.

I think the best test in a comparison is a simple log frequeny/contrast chart. You just put all the results next to each other and judge. There is no absolute number but you can see how good it is in real world situations since you see above and below aliasing and forms of artifacctng. How it resolves and how it aliases and how bad and all that. A camera might appear to resolve and simply be full of artifacts and problematic in real life.

Take a look at this. The first camera has got excellent performance. Smooth even beyond its resolution limit. The second one is a typical badly filtered implementation that will create problems with patterns in fabrics, building windows etc. In a resolution chart, the bad camera might appear good depending on the chart or the relative position of camera/chart. Somebody that does not know better might even think it resolves beyond its resolution limit since there are aliased points that look resolved! Panning the camera a little bit would change the results to something different. This happens a lot in resolution tests done by camera operators (non engineers).

On the second camera, the right half will jump all over and produce funny patterns due to aliasing. You can see this problem on the moving camera chart MOVs from that test.

 
Barry_Green said:
You can't test the XLH1 at 11, because it doesn't go to 11. Its iris is limited to 9.6.

The JVC has that capability. The Sony goes to 11 as well.
Click to expand...

To be fair, the JVC has it's best work at around 4 as well. Above thar=t it doesn't look as good... at least in our limited testing of that. In fact the odd chroma smearing that was rare seemed to be tied to iris, though we didn't have time to go back again...
 
Petrus said:
Yes, using the ND filters and opening the iris is a good, even great idea.
Click to expand...

Here in Arizona where we can get a 4-6 f/stop swing between open (bright )and covered (shaded) areas, we've gotten in the habit of using shutter speed to get it back down to the lower f/stops to control DOF...
 
Mitch_Ives said:
Here in Arizona where we can get a 4-6 f/stop swing between open (bright )and covered (shaded) areas, we've gotten in the habit of using shutter speed to get it back down to the lower f/stops to control DOF...
Click to expand...

What are you shooting? If you are shooting fiction or scripted work with actors doesn't the change in shutter speed seem very drastic from scene to scene? If you are shooting more nature stuff I would think that wouldn't be as big of an issue.
 
I think the major reason for the problems with the HVX200 is the small CCD. It is only 960x560. They use pixel shift to make a resolution of 720.

The result is a much light sensitive camera but also a camera with lower resolutions.

All sub $10000 cameras has their pro and cons. I start thinking that Sony PWD-F330 would be the best low cost alternative. But it is sub $20000.
 
icicle22 said:
What are you shooting? If you are shooting fiction or scripted work with actors doesn't the change in shutter speed seem very drastic from scene to scene? If you are shooting more nature stuff I would think that wouldn't be as big of an issue.
Click to expand...

Precisely, it can have unwanted effects under certain conditions, so one has to be careful. If shooting 24p, you definitely have to know what the results will be.

With the HVX we may not be able to do that... may have to go back to ND's on the camera plus ND filters in the matte box
 
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