Sweetest ISO for the T2? at DVinfo.net

Go Back   DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon EOS Crop Sensor for HD

Canon EOS Crop Sensor for HD
APS-C sensor cameras including the 80D, 70D, 7D Mk. II, 7D, EOS M and Rebel models for HD video recording.


Reply
 
Thread Tools Search this Thread
Old May 14th, 2010, 02:40 AM   #1
Trustee
 
Join Date: Sep 2005
Posts: 1,063
Sweetest ISO for the T2?

Just watched the Zacuto DSLR shoot out part 2. In it, the DPs explained that every DSLR camera tested had an "ISO sweet spot" where there would be less noise then at other ISOs, even if they were higher ones.

Essentially meaning that if you could properly light at that ISO it would have the least amount of camera generated noise.

Does anyone know what that ISO is for the T2 or how you'd test this? Thanks -

john
John Vincent is offline   Reply With Quote
Old May 14th, 2010, 04:02 AM   #2
Major Player
 
Join Date: Nov 2006
Location: London, UK
Posts: 321
If the native ISO is 160 then 200 ISO might be the cleanest?
Fergus Anderson is offline   Reply With Quote
Old May 14th, 2010, 04:19 AM   #3
Major Player
 
Join Date: Apr 2010
Location: Chelmsford England
Posts: 287
Quote:
Originally Posted by John Vincent View Post
Just watched the Zacuto DSLR shoot out part 2. In it, the DPs explained that every DSLR camera tested had an "ISO sweet spot" where there would be less noise then at other ISOs, even if they were higher ones.

Essentially meaning that if you could properly light at that ISO it would have the least amount of camera generated noise.

Does anyone know what that ISO is for the T2 or how you'd test this? Thanks -

john
You cannot escape the fact that in reality, higher ISO means more noise.

On the 5d mk II and 7d, there are 'intermediate' ISOs values which at first glance, look like they offer lower noise, but really they are under/over exposed versions of the standard values. A useful feature for managing shadow / highlight detail, but not one which defies the laws of physics.

If you plotted ISO noise against true ISO value for any sensor, you would clearly see noise going up with ISO.

Likewise, you would see dynamic range going down as ISO goes up.

The long and short is, on the T2i, ISO 100 has the least noise and the most dynamic range.
James Donnelly is offline   Reply With Quote
Old May 14th, 2010, 06:29 PM   #4
Trustee
 
Join Date: Sep 2005
Posts: 1,063
"You cannot escape the fact that in reality, higher ISO means more noise"

Well, you'd think so, but they clearly indicate that's not the fact:

The Great Camera Shootout 2010 - Film Vs DSLR Comparison | Zacuto

Interesting idea about 200 being the best ISO...

jdv
John Vincent is offline   Reply With Quote
Old May 15th, 2010, 04:45 PM   #5
Major Player
 
Join Date: Apr 2010
Location: Chelmsford England
Posts: 287
Quote:
Originally Posted by John Vincent View Post
Well, you'd think so, but they clearly indicate that's not the fact:

The Great Camera Shootout 2010 - Film Vs DSLR Comparison | Zacuto
I saw that video before I got my camera, so I can't remember exactly what they said.

There are sweet spots in ISO in some ways. For example, ISO 100 and 200 often have similar noise and dynamic range levels, even though 200 captures double the light. However, I repeat what I said, when ISO goes up, so does noise. It can't go down.

I agree that it seems to be the case that this CAN happen, but I will try to convince you that it's in fact not really happening.

Here are the intermediate ISO values that seem to be ISO 'sweet spots', or 'better than their lower neighbor on the dial':

160, 320, 640, 1250

These values are not true ISO settings on the sensor. They are respectively set on the sensor at:

200, 400, 800, 1600

There is then applied a 1/3 stop reduction in exposure. If you were to analyse the latitude for highlight detail in these 'ISOs' you would see that it is inferior to other values.

Likewise, lets take the intermediate ISO values that seem to give more noise than the others:

125, 250, 500, 1000, 2000

These values derive from the sensor being set at respectively:

100, 200, 400, 800, 1600

with a 1/3 stop over exposure being applied. In this case, you will see less shadow detail.

In other words, as I stated before, these settings are a convenience for managing exposure, and do not give something for nothing in ISO terms.

By the way, there is no such thing as 'native' ISO as such. ISO in DSLRs is simply the gain, or power applied to the sensor. ISO is used as a convenience term in stills cameras to give continuity to film users

Let's not forget, these intermediate ISOs are not available on the t2i, but as I have indicated, you are not really missing anything.

If you want to confirm that there is a one way relationship between gain and noise, see the DxO test for the T2i:

EOS 550D
James Donnelly is offline   Reply With Quote
Old May 21st, 2010, 12:14 AM   #6
Trustee
 
Join Date: Sep 2005
Posts: 1,063
Hey, good stuff James - thanks for the info...

So you'd shoot at ISO 100 all things being even?

jdv
John Vincent is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Canon EOS / MXF / AVCHD / HDV / DV Camera Systems > Canon EOS Crop Sensor for HD

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 06:37 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network