Barry: Latitude & Sensitivity of 1/3" cams

stephenvv

stephenvv

Well-known member
After reading you report (thanks so much to organizing it and to all who helped put it togther., I'm even more on the fence about 1/3" HD cams. The extra rez is exciting but latitude & sensitivity has me worried about giving up my DVX100a. A few questions.

First, if I understand Barry's report correctly - the HD100 has the greatest latitude range although it's less sensitive & noisier. The HVX is the sensitivity winner but falters in highlight handling and shadow detail with moderate, grain-like noise. How many stops of exposure did you get with each cam?

Second - how would this compare with the DVX100a and DVX100b?

Third - How much more latitude will a 2/3" sensor give? How much more sensitivity in a $20 - $30K cam.

I realize the technical problem is that engineering dicates squeaking more rez out of 1/3" sensors means something has to go. I'm wondering though if 2/3" is going to be the sweet spot for HD cams.

How about a $15k 2/3" HVX300 :thumbsup:
 
stephenvv said:
First, if I understand Barry's report correctly - the HD100 has the greatest latitude range although it's less sensitive & noisier. The HVX is the sensitivity winner but falters in highlight handling and shadow detail with moderate, grain-like noise. How many stops of exposure did you get with each cam?
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From my experience this is not a correct assesment. The HVX has 1/3 stop more latitude than the H1 and maybe 1/3 less than the HD100. None of these "falter" in any way. There are differences but all have very useable, beautiful images in thier own way.
The HVX most definately has more DR and better highlight rendering than the DVX series.
 
evinsky said:
From my experience this is not a correct assesment. The HVX has 1/3 stop more latitude than the H1 and maybe 1/3 less than the HD100. None of these "falter" in any way.
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Wrong word choice - I meant "less than the HD100".

The HVX most definately has more DR and better highlight rendering than the DVX series.
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This is the #1 issue for me and I hope Barry will agree. I don't want to take a step down in DR and highlight handling/shadow detail from the DVX.
 
Understand that when we're talking about the differences in highlight handling, we were talking about a two-stop-overexposed picture, and the HD100 blew out the top 3 chips of a 10-chip chart, the HVX blew out the top 4, and the XLH1 blew out the top 5. We're not talking about night and day here, it's fairly minor differences; I'd think Evin's guess of 1/3 stop difference is probably accurate.

I'm sending the footage to Adam Wilt to get his take on things.

I haven't done any HVX vs. DVX style testing; Evin knows the DVX inside out and has commented repeatedly on preferring the DR and highlight handling on the HVX; the man knows his stuff so I would tend to say listen to Evin. Eventually I'll get to doing some side-by-side between HVX and DVX.
 
Sensitivity wise , I believe a 1/3" chip will always be slower than a comparable 2/3" chip because there is just less light being gathered. I thinks its just physics and I'll bet the size of the comparable lens plays a part also. Bigger lens, more light.

I think also more pixels on equal sized chip is additionally slower (maybe less light per pixel though I'm not sure about this stuff). This would explain why an HVX might be slower than a DVX (though other engineering issues apply as well - & newer is usually faster)

Latitude wise, My suspicion is its the electronics you are paying for in the bigger cameras that enable the camera to handle highlights & shadows better, rather than the size of the chip.
There's just alot more engineering in a $20 - $30K or $60K camera.
 
May somebody give an explanation to what the following words mean?

1. sensitivity
2. latitude
3. dynamic range
4. highlights
5. shadows

I always hear them, but sometimes I have got the feeling, that I do not understand them right.
 
Robert_Niemann said:
May somebody give an explanation to what the following words mean?

1. sensitivity
2. latitude
3. dynamic range
4. highlights
5. shadows

I always hear them, but sometimes I have got the feeling, that I do not understand them right.
Click to expand...

From my understanding now, sensitivity is how sensitive the camera is to light. For example point the same camera at the same scene and one may have an f-stop of f5.6 while the other hs f8. The one with the f8 setting is more sensitive and I think a stop faster than the other camera. i.e. it needs half the amount of light to expose the same image.

Lattitude is the range in the darks to brights that the camera can expose correctly - this means without crushing the blacks or 'bleaching out' the whites. For example, we all know pointing a video camera at the horizon is a bad idea because either the sky will bleach out or the ground will be totally dark. This is because the camera has a limited lattitude. In 1/3 ccd cams its around 7 stops. Film I beleive is around 11 stops, so if you shot the same scene with a film camera you would beging to see detail in the highlight and shadows. The human eye I read was 15 stops. So this gives you an idea.

With these cameras, discovering their lattitude would mean filming the same scene and seeing at which point the highlights became bleached out (lost detail) and also which image seemed to deliver more detail in the shadows.

dynamic range - to be honest I thought this was the same as lattitude - but maybe dynamic range takes into account everything. Sensitivity, noise, lattitude.

Highlights and shadows, well 8 bit video has brightness levels from 0 to 255. 255 being pure white and 0 being black. Highlights would be anything that falls in the top end of the chart and shadows in the bottom. I cant give exact values as its a bit subjective, there isnt a specific point at which a midtone becomes a highlight, it has a lot to do with the eye and the shot.

So in terms of lattitude it is that point at which the camera says - well all of this is 255 (showing an area of pure white with no detail in it). Other cameras may be able to say "actually this isnt all pure white its a range of 233-245" so it maintains detail instead of bleaching out that part of the image. This camera would have more lattitude and hence better highlight handling. (and also be a talking camera)

Im sure Barry could explain it better.
 
Barry_Green said:
HD100 blew out the top 3 chips of a 10-chip chart, the HVX blew out the top 4, and the XLH1 blew out the top 5. We're not talking about night and day here, it's fairly minor differences; I'd think Evin's guess of 1/3 stop difference is probably accurat.
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Okay, but the DVX Cinegamma curves don't have much highlight handleing room in return for better latitude and I've always shot to compensate for that.

I can see that a two camera shootout is more productive because it would be interesting to see a look at that various gamma curves of the HD100 and HVX to see exactly what latitude you can get out of the two cams with the extensive settings.

Of course, the well-pocketed can just order both and test away :laugh:
 
But what about DVCPRO50?

But what about DVCPRO50?

I read somewhere that because the HVX has squeezed in so many pixels onto a 1/3" that the latitude will be compramised (relative to the DVX). Regardless, does the HVX have more latitude in DVCPRO50 mode? Or is it basically the same pixels per inch just the sides cropped off?

JonnyH
 
The HVX has a better lattitude than all the DVX ( 100, 100A, and 100B).

To my eyes, it has the exact same lattitude no matter if you shoot DVCPro HD or DVC Pro 50.
 
Antoine_Fabi said:
To my eyes, it has the exact same lattitude no matter if you shoot DVCPro HD or DVC Pro 50.
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That would make sense, lattitude should be primarily a function of the CCD and image processor, not the codec.
 
Don't get me wrong...I love the HVX.
But I am surprised that the HVX has more latitude than the XLH1. Now the HVX Cinelike Gammas do a great job for increasing the latitude (as did the DVX). It's not as simple with the XLH1, as you can (or need to) adjust knee, black stretch and cinegamma independently. I really don't like the look the XLH1 gives you out of the box...especially compared to the HVX...but it's magic when you get into the menus of the Canon.
Please keep in mind, the -3db setting helps with noise on the XLH1 but reduces the dynamic range significantly (FYI).
Anyone else have any experiences? I'd love to hear em...
Cheers!


Brian Broz
www.llsr.com
 
well, according to July's AC issue (which has a nice article about the Andromeda guys), a DVX with andromeda installed has significantly higher latitude range than the OEM DVX. So also probably higher than an HVX.

But OEM - out of the box HVX compared to DVX? Antoine_Fabi seems to deliver a direct and convincing message on that one.
 
I'd just like to say how sick I am of these discussions about the technical details/specifications of the HVX (resolution, latitude, etc...). Look at the image the HVX delivers. That's all you'll need to know. Nothing else matters.

P.S.: Jonnyh1968,
I have no way of knowing this for myself, but I hear that there is no sanctuary.
 
Brian Broz said:
Don't get me wrong...I love the HVX.
But I am surprised that the HVX has more latitude than the XLH1. Now the HVX Cinelike Gammas do a great job for increasing the latitude (as did the DVX). It's not as simple with the XLH1, as you can (or need to) adjust knee, black stretch and cinegamma independently. I really don't like the look the XLH1 gives you out of the box...especially compared to the HVX...but it's magic when you get into the menus of the Canon.
Please keep in mind, the -3db setting helps with noise on the XLH1 but reduces the dynamic range significantly (FYI).
Anyone else have any experiences? I'd love to hear em...
Cheers!


Brian Broz
www.llsr.com
Click to expand...

Well technical the XLH1 has 1/3 cdds as the HVX but it also has 1440*1080 pixels on the sensor compare to the 960*540 sensor of the HVX. Thats shows that the XLH1 smaller sensors on its ccd. The benifit is you can get higher res without using pixelshift, the downside should be that you will get worse latitude. Sure you can mix different settings to get as much latitude you want but you cant get more than the sensor will give you. Also you cant get more than the codec will allow.

As I understand Latitude and Low light was the reason Panasonic put a lower res senor in the HVX. If it didnt have those benifits they could have choosen the same chip as Canon did.
 
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