High ISO capabilities

[GerryDS]

Can anyone explain why the camera with the smaller lens is capable of a higher ISO; the Z1085 IS captures at an ISO up to 3200 at 10MP, the Z1012 IS can only capture up to an ISO of 1600 at full resolution.

 

[GeorgeH]

High ISO on the small Kodak cameras are more of a marketing ploy. The high ISO settings at 3200/1600 are not really usable.

Can anyone explain why the camera with the smaller lens is capable of
a higher ISO; the Z1085 IS captures at an ISO up to 3200 at 10MP, the
Z1012 IS can only capture up to an ISO of 1600 at full resolution.

 

[MuumiTroll]

It doesnt depend so much on lense or chip the camera has. It depends more on marketing and on decicions, what camera makers do - to allow or not allow bigger ISOs. Anyway, ISO over 800 on compact camera is probably marketing trick and not usable in practice. Ok, maybe cutted MP iso 1600 has some use, but not more.

True and not true : The more zoom camera has, the more ISO it needs, because of 1/(focal length) rule for shutter speeds. It means, if you do 35 mm pic, then usually 1/35 sec is needed for shakefree image, if 400 mm, then 1/400 is needed. To get these shutter speeds, you need more ISO (rising ISO twice, you can use twice quicker shutter speed). Of course, all is not so rosy in real life. Image stabilization helps to get maybe 2...8*1/(focal length) rule [tripod helps much more].

--
http://muumitroll.pri.ee/pildid/

 

[acsmith]

The sensors are of a different size on the two cameras. 1/1.72 on the 1085 and just slightly larger the 1/2.5 on the 1012.

 

[Cyril Catt]

GeorgeH wrote:
The high ISO settings at 3200/1600 are not really usable.

The high ISO settings are in fact quite useable, although they may not often be useful. For instance, with a Z885, in full sunlight, a 1/2000 second shot at f8 and ISO 3200 will freeze the motion of moving objects such as passing cars, whilst giving a fairly good depth of field, making an excellent tool for candid camera work. Alternatively, an 8 second time exposure at f2.8 and ISO 3200 taken in full moonlight will produce a full colour picture that looks like it was taken in daylight. At much smaller resolutions, settings of ISO 6400 or 8000 in very poor light give much granier pictures, but do provide pictures similar to the quality of night vision scopes, but in colour.

These are certainly not as good as could be achieved with DSLRs and appropriate special lenses, but in particular circumstances they are both useable and useful - and, most importantly, available at only a fraction of the cost.

acsmith wrote:

The sensors are of a different size on the two cameras. 1/1.72 on the 1085 and just slightly larger the 1/2.5 on the 1012.

Wouldn’t a 1/1.72 sensor have about double the area of a 1/2.5 sensor, and therefore be potentially more sensitive?

Wouldn’t a 1/1.72 sensor have about double the area of a 1/2.5 sensor, and therefore be potentially more sensitive?
--
Cyril

 

[acsmith]

acsmith wrote:

The sensors are of a different size on the two

cameras. 1/1.72 on the 1085 and just slightly larger than 1/2.5 on the
1012.

Wouldn’t a 1/1.72 sensor have about double the area of a 1/2.5
sensor, and therefore be potentially more sensitive?
Cyril

Uh - that was my point. The larger, hence more sensitive sensor on the 1085 allows Kodak to offer higher ISOs on that camera. This is offset very slightly by the lenses offered. The 5x of the 1085 is f5.1 at 175mm equiv. vs. f4.8 at 396mm for the 1012. At 175mm the 1012 will be a stop or more faster.