Steve Kahn
Well-known member
+1
That would be my quess as well. Still, it would be nice to know the S/N and soon enough we will.
Is anyone going to do a signal to noise ratio test?
- Thread starter Duke M.
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+1
That would be my quess as well. Still, it would be nice to know the S/N and soon enough we will.
Barry_Green
Moderator
Yes it's unusual, but it's also nothing new, they've been doing it this way for at least the last 8 years.
I have no information on the s/n ratio on the AF100. It hasn't been published and I haven't seen it. All I've seen is the footage, which looks shockingly good.
That's exactly what I said too. I haven't seen it. I saw it for the HPX370, but that's the only AG-series unit I've ever seen it for. And that was never published. And, as far as I know, the HPX370 is an oddball in the lineup anyway because it's called an "AG" but it's actually built by the "AJ" factory, and therefore that may explain why the number even existed in print somewhere. They publish S/N ratios for the AJ's, but not the AG's.
Jan probably hasn't seen the number either, because there may not be one to see.
Brian@202020
Veteran
Bottom line is I think the benefits of telling the public these numbers are minimal and the drawbacks from not telling the public is also minimal. I mean if the numbers were really good do you think they would sell a lot more of them? Probably not, but if the numbers were just a little worse than Sony's numbers it could contaminate a launch of an amazing camera at an amazing price. I just want to put it thru it's paces, find out it's limitation (which all cameras have), and adjust accordingly. I'm sure it'll be great.
Barry_Green
Moderator
Okay, guys, full stop -- let's stop with the speculation that only ends in casting innuendoes. Let's instead do a little research.
Can someone please tell me the signal to noise ratio of the Canon XLH1s? No? Why not? Oh, it's because THEY DON'T PUBLISH THAT SPEC.
Well, what about the new XF300, which they're so proud of? What's that? No snr published? Why not -- are they EMBARRASSED? Are they so horrified by the performance of the XHA1 that they've decided never to publish the spec again? Or maybe, just maybe -- it's not common practice and as a routine matter of policy they just don't publish these specs?
How about JVC? Surely someone here can tell me the S/N ratio of the brand-new, top-of-the-line JVC HM790, right? Oops... just looked, and guess what -- they don't publish the snr!
So let's go back to Sony, who will surely publish THEIR snr figures, right? Because they're so up-front and they're so proud of their SNR, right? Go look for it. I dare you. Go find an SNR for any HDV or NXCAM product in their entire lineup. It doesn't exist. They Don't Publish That Figure. Not even for their EXMOR-R products.
It's just not done. It's not a standard industry practice. Nobody publishes it, on this range of products. The only place you'll find a published SNR is on the top-end products (such as the Panasonic AJ or the Sony PMW/PDW type series).
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Steve Kahn
Well-known member
Well, in all fairness it IS published by Sony for the EX-1.
But, correct me if I'm wrong Barry but isn't it a simple thing we can test with a lens cap and vectorscope?
But, correct me if I'm wrong Barry but isn't it a simple thing we can test with a lens cap and vectorscope?
Brian@202020
Veteran
I noticed you didn't quote the rest of my post which pretty much said who cares about the S/N ratio, I don't. Plus I also posted after that saying it again. All I was saying is the HVX200 was one of the noisiest cameras I've used and it would explain things a little. That said it was still an awesome camera and revolutionized the camera world in a lot of ways, hell I still use one from time to time.
Barry_Green
Moderator
Yes, for the EX1. And that's the only camera anywhere near this price range that it's published for. And that camera is built in the other factory (along with the PDW800). They made a big deal of that when it was announced; it's not coming from the pro line, it's coming from the broadcast line, which is why it gets to wear the cinealta badge. It's a different line. But again, go ahead, find the SNR for anything else, from this comparable lineup. It's not published.
How? By what measure? A vectorscope doesn't measure luminance at all, only chroma.
You can use Imatest to test it, but look at their description of the process and the various ways that it can be tested for. http://www.imatest.com/docs/noise.html
If you want to do a real test, you should do it according to the ISO's procedures. And you have to spend 112 swiss francs just to buy the document that tells you what the procedures are!
http://www.iso.org/iso/iso_catalogue/catalogue_tc/catalogue_detail.htm?csnumber=28835
You can get a quick reading off of certain waveform monitors measuring tools, but whether that would hold up to the ISO's 112-francs standards (and therefore be usable for comparison) I don't know.
Barry_Green
Moderator
Right, I didn't, because the blood vessels in my brain had already snapped. There are just certain things that I really, really, don't get. And they keep getting repeated over and over.
"There's no wide lenses for m4/3." My 7-14 would disagree with that statement.
"There are no fast zooms for m4/3." Compared to what? There are faster zooms for 4/3 and m4/3 than for any other large-sensor format out there.
"Panasonic's hiding something by not publishing the SNR." NOBODY publishes their SNR, in this price bracket/product category.
So I'm just trying to inject some rationality into the conversation by saying "no more conspiracy theories, no more suppositions, just look at the facts and the common industry practices."
I totally agree with you, I don't really care about whether the SNR is published or not, and it's a non-issue because nobody (in this range, for this type of product) publishes it. But I disagree about any speculation that they're trying to hide something or are embarrassed by past products.
Brian@202020
Veteran
I hear ya. I'm trying to put out the fires too, just taking a different approach and trying to relate to the conspiracy theorists and tell them it's no big deal and who cares.
Steve Kahn
Well-known member
Actually I said vectorscope but meant waveform. I thought one could put on a lens cap then look at the waveform. Any flickering ire at the bottom could be interpreted as noise. Wouldn't that work???
Thank you for the info. Love to learn all I can.
Barry_Green
Moderator
Well, you could see that there was noise there, but how do you measure it quantitatively and accurately without appropriate test equipment? And then what do the settings do to it? I can make the appearance of noise grossly exaggerated (by raising the MP and setting detail level +7/ v-detail level +7) or I can make it disappear (by setting all those things to the opposite). So which is the "real" noise signature? And which do you measure, for comparison with any other product?
Steve Kahn
Well-known member
Well I don't know. You're the expert. :thumbsup:
But if I were to guess for a given setting under a closed iris if one could see a flickering 2ire and then assuming the maximum signal is 110ire your S/N would equal 55.
But, to be honest I really don't want to compare to other cameras. It would really be more enlightening to know which settings cause what kind of noise and how much. IMHO it would be helpful to know the strengths and weaknesses for shooting purposes alone.
But if I were to guess for a given setting under a closed iris if one could see a flickering 2ire and then assuming the maximum signal is 110ire your S/N would equal 55.
But, to be honest I really don't want to compare to other cameras. It would really be more enlightening to know which settings cause what kind of noise and how much. IMHO it would be helpful to know the strengths and weaknesses for shooting purposes alone.
Coolbreeze
Member
Dino
Veteran
With broadcast 2/3" cameras, we'd normally turn off detail and matrix(as well as multi-matrix/color correction), make sure black stretch was off, but leave gamma on(but different gamma curves will have different noise levels). It's easy to expand the waveform and measure the IRE of luma noise if the flat filter is turned off, or chroma noise with flat filter left on. Every manufacturer will express SN ration differently, however, so not very reliable. Ditto latitude and resolution.
OK Barry's answered questions beautifully thus far. He has even given an explanation on how to conduct the SNR test. Go ahead and do it when the camera is out if you like.
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