EXDCAM EX's ISO Speed??
 

We are all aware of the EX's great low light abilities, but what I really would like to know is what is the CMOS chip's real ISO speed (or ASA) is?

Coming from an education in film, where we didn't have the luxury of seeing how our images are exposed, this question is really for all those, like myself, who haven't not yet had solid experience with the HD digital format that would like a bench mark in regards to lighting for the XDCAM EX.

Around 320 to 400, depending on your gamma curve.

Boost the gain and the ISO can go up a lot, along with your noise.

John, I'd say it's over 400.
The z1 I have is about 160 according to adam wilt's texas shootout and the ex1 excels by at least 1.5 - 2 stops. As Eric said - depends on you gamma and other settings.

There are ways to fine tune the camera so that noise is minimized as you gain up. I'm still trying to build profiles which optimize the following three situations so that exposure range is maximized and noise is minimized. Since I do mainly weddings - that would be

1)inside dark to barely enough light (reception)
2)inside good light and (tungsten or FL lighting)
3)outside overcast
4)outside sunny
5)general profile

Thanks
Paul

Paul....I would love to see your picture profiles when you get them done!
Please share with us.

THANKS!!!!!

Yes, thanks Paul.

From everything I've read and tested myself - 800 asa or iso

Jack - 800 ASA or ISO sounds more like it. I've played arround with other digital camera's and their ISO's have been well above 320.

Jack -- What sort of tests did you perform to arrive at 800 ASA?

Has anyone else preformed proper actual test to get the camera's exact ASA or ISO at the camera's default setting or any of the other Cine Settings?

Having the correct ISO would allow me and others pre-prepare any lighting set ups with out the need to have the camera present using just a light metre. Knowing this fact could help us save time and money.

John, my test was definately not scientific by any means - :P
Purely guessing here. I'll definately try with a light meter soon - would be interesting to know. I have heard numbers in the 800 range as well so I may be off.

I was just testing dumps from card to laptop - just firing the camera on and off and dumping - seeing how long it takes. (Which by the way is pretty quick - took me like 6 minutes to dump a whole 8 GB card)

I'm sitting in a room with a 25 w bulb (shaded table lamp) - just a small bit of light barely illuminating the wall on the other side of the room. The EX1 could see the wall perfectly clean on 0db (I had to look again to make sure it wasn't gained up) It could even recognize the colors on objects very well.

I grabbed my z1u and canon hv10 and tried the same - pitch black on both.

I turned on a 100 watt bulb so that I could make a more accurate comparison
I equalized the f-stop on both and had to take the z1u to 12DB to make the picture match up. The zebras were lit up equally at that point. The z1u even has black stretch on. The z1u was open on 1.6 vs. the ex1's 1.9. Still the ex1 picture was much clearer, finer, wider and more natural.

I you shoot at 9 db regularly on the z1 - i'd say you can stay at 0 db on the ex1 and ur fine. Noise levels are pretty clean to me and i'm really anal about noise (I know we shouldn't be - as someone suggested before - focus on content)

I find if you have 'some' illumination on the object and you gain up it's quiet. No illumation (dark cornors) - yes there is a tad bit of noise at high gain. Nothing more than the z1 would generate though. You can't amplify nothing (dark) and make it clean and white. You have to have a tiny bit of light out there - then amplify (gain) - then it looks nice. I saw some comments where people are shooting outdoors at night and saying they see noise. I'd say tweak gamma to crush the blacks slightly go to -3db and notch it up a touch in post (if u want) - that will give you a clean picture. If you go the route of amplifying initially and try to make the black sky bright - yes at 6 db you'll see noise. 6 db on the ex1 is probably like 18-20 db on the z1u - so yaaa there will be a bit of noise. The camera is awesome but it's not a human eyeball so don't expect miracles - but expect to be pleasantly surprised.

Great cam!

Just rambling :)

Thanks
Paul

At the road shows it was reported at 800 ISO at -3dB, which looks about right. But it will depend on how you set it up.

EX is exactly one stop faster than the 350.

350 at -3db, Cine 4, 24P and 1/48th shutter is 160 ASA
Same setup with EX is 320 ASA

350 at 0db, Cine 4, 24P and 1/48th shutter 240 ASA
EX setup with same 480 ASA

350 at -3db, Cine 4, 24P and no shutter is 320 ASA
EX setup same is 640 ASA

Do the math for other combinations. All readings were taken with 18% Gray card and spot meter.

The test I did were measuring against a light meter and a canon mkIII. Using iso 100 as a base, the EX1 is very close using ND1. When ND1 is turned off, there is a three stop difference. When tested again the three stops it is very close to iso 800. The ND2 is 6 stops darker than no ND or iso 12 1/2. The benefit of working with #s is being able to dial in quickly to a proper shutter, iris, and ND setting. In still photography I try to teach students to have the settings in their mind before looking at the meter.

Paul, Steven - apologies I didn't see your request :P

I will certainly post them as soon as I prep them

Cheers
Paul