HPX170 Lens Wobble Improved

Jay Rodriguez said:
Kholi, get off your arse and do the test dude.... I've been waiting big homie! :beer: The noise is really bothering me too to be honest.... I can't get anything clean. Noise will be always be around on these lil cameras but none of my footy looks clean/good to me when shown at full rez.....
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I've been looking for a 200A. Even the rental houses will let me come and test but not until next week. So it's gonna have to be next week!

But, soon.


As far as Cold Calls/Barry's post -- Objectionable? Opinion. Same as 200A? No. Not my camera, not Dino's, not Willis', I haven't seen any footage from the HPX170 that looks as clean as 200A footage. I see an obvious grain pattern in Cold Calls' footage. Looks like grit over the entire image. But, it probably isnt' a big deal. I bough the HPX170 under the impression that it was the same image as the 200A but might be a tad slower because of the smaller lens diamtere. Not the case.

Whether the noise is acceptable? Well, look how many people used the HVX200 and for how long...
 
Kholi,

I agree, there is a layer of grit over the entire image, not just mid-tones, not just luminance noise, I see chroma noise on a chip chart. Not chroma noise anywhere near the level of a cheap consumer single-chip palmcorder, but I don't like seeing any chroma noise at 0db on a chip chart.

I was checking the lens light tracking and here's what I measured:

12mm/Z49=100ire
22mm/Z76=90ire
38mm/Z91=80ire
51mmZ99=75ire

That's a 25ire drop in exposure from 12-51mm. That's a lot of light loss compared to 2/3" HD glass, which drops about 10ire near the end of the lens. Obviously there is a huge price difference, but it's easier to make a lens for a 1/3" imager than a 2/3" imager.

I think Panasonic saw that they had a pretty slow camera when zoomed in and compensated with preamp gain, and that gives me a better understanding as to why the 170 is actually more sensitive at wider focal lengths than a 200A. Clearly the smaller diameter lens of an HPX170 is more affected by light loss than a 200A's 10mm larger diameter lens.
 
The light falloff is known, that's why the lens is rated at 1.6 at the wide end and 3.0 at the tele.

The HVX200's lens is affected a little less, it's 1.6 to 2.8.
 
Dino, let me ask you as to whether you believe this image degradation on the 170 is isolated to a few cams or it's on mass. I was ready to pull the trigger and buy a 170 but this news is absolutely a show stopper for me. Barry, I've been reading your posts and it's a pleasure to have your expertise to lend balance, but I have to believe at this point you must be realizing that there is an issue with the 170 not being as clean as the 200A. After all the hard work Dino has been doing to verify this issue, it's a conclusive fact at this point. I'm hoping Pany will openly embrace this issue and remedy it quickly, if possible. Thoughts Dino? Thoughts Barry?
 
I'm going to run side by side tests at our local rental house next week too. Sounds like Kholi will do the same.

Personally, this is as noisy or less noisy than my former Canon A1 (we'll test that too) and that noise as little as it was didn't bother. So if this camera is that much noisier than the 200a, I guess we'll find out. Seems pretty darn good to me.
 
Barry_Green said:
The light falloff is known, that's why the lens is rated at 1.6 at the wide end and 3.0 at the tele.

The HVX200's lens is affected a little less, it's 1.6 to 2.8.
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Thanks Barry. It's good to know what the difference is at the full telephoto end of the lens is between the 200A and 170. Looks to be a smaller difference than I would have thought. So the question is why did Panasonic decide to increase the
sensitivity on the 170 at the expense of signal to noise?
 
Hovander said:
Dino, let me ask you as to whether you believe this image degradation on the 170 is isolated to a few cams or it's on mass.
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I have no way of knowing. I have given a Panasonic engineer in NJ the settings, lighting setup and charts that I have used to test with. Right now we have three forum members, including myself who think there is a difference in noise between a 170 and 200A. We are talking 2-3 db difference probably, so it's not a blatant difference, but with proper monitoring in a A-B setup it's clear.
 
I got some interesting results tonight. I was shooting with the redrock in very very low light conditions outside and the sky and the overall image was pretty noisy and dark, so I cranked the gain up to 9db and the image seemed to clear up and look more noise free than with 0db? I'm going to take a look at the footage here in a little bit.
 
Kholi said:
WTF? Are you sure about that?
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yes, unless my eyes were playing tricks on me.

I was shooting at sunset and I was getting a ton of noise in the sky and darker areas, so I switched to 9db and the noise decreased overall. The "luma" noise seemed to go away with the gain increase. Of course there was still noise, but not nearly as much. Maybe my eyes were just messing with me. Give it a shot yourself and see what you get. I'll try this again with the stock camera, I was shooting with the redrock. Also, it's tough to judge from the little LCD, so I may be way off on this. I'm just going with what I saw at that moment. A more formal test may prove this completely wrong.
 
Hmmm... I'm having more second thoughts about this camera. I figured you were going crazy, but I just tried 12dB after someone else on these boards said "that's what I found too!" and...

It looks the same as 0dB just with more light.

I guess it might be time to go Sony...
 
can anyone possibly post some side by side comparisons with imagery from the 200, 200A & 170 to illustrate this gain issue?
 
It needs to be video, for one. Stills won't really show the pattern of moving grain, gain. If I could find a 200A I would do it in a heartbeat but can't until next week.

Dino has been the only one so far to be able to have both side by side.
 
I tried going into +9db and I felt the same way--noise stayed constant, not appreciably worse
than 0db. Very odd, let's make sure AGC is turned off for sure.
 
Dino, try this setting: Detail -3, Detail coring +3. With this settings the image seems clean on my monitor and has still enough resolution

Gary
 
My settings have been like that for ages and still look cleaner on the 200A then they do on the 170.
 
Kholi, in July I've buyed an HVX201 and in october I've changed it with an hpx171 (european models). You're right, the hpx171 shows more noise than my previous camera, but the difference is not dramatic, in my opinion.
On the other hand now I have less weight, an HD-SDI output, a flippable monitor with undercsan/overscan, a waveform, a vectorsope, a powerful focus assist, more framerates and a multistandard camera. This camera is simply perfect for using with 35mm adapters.
It seems that the noise is the price I have payed, but this baby is much more powerful, productive and friendly than my previous 'fat girl'.

Anyway I can agree with you and I also am a little disappointed

Gary
 
I would have been all fine with that... had I not been told that the 170 and 200A had the same image. Then I could have based "upgrading" on that information. We were all lead to believe that they were the same image, though, and that's unfair.
 
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