Auto ISO

[briansquibb]

Re: Auto ISO

This is the first time I have had it - the 50D was stuck on iso400

[MX5]

Re: Auto ISO

This thread, the link to DPreview, and some stuff Canon have produced about their new 300C Click have had me thinking ...

Each camera has a native ISO (it's ISO 850 ** on C300, but I haven't had confirmation what it is on say the 7D or 5D2, but guess it's ISO 100?). As the (DPreview) article says 1 EV increments are carried out electronically (i.e. amplification to 200, 400, 800 et seq), whereas intermediate values are done in software. This goes some way to explaining why (say) ISO 200 yields 'better' results than ISO 160 in a DSLR.

** The EOS C300 has a native ISO of 850. It is at this setting that dynamic range, especially in highlight areas, reaches its maximum. At lower ISO settings, the dynamic range tends to shift more toward shadow detail.

[Trevoreast]

Re: Auto ISO

The auto iso on the 7D is a "souped up" useful version of what was on older xxd EOS cameras.
On my 40D If you tried in manual it wouldn't work, it would just give you ISO 400 no matter what.
In AV or TV it wasn't much use.

I don't know what auto iso is like on a 5Dmk2 maybe others can comment.

Trev

[Neilly]

Re: Auto ISO

Hi Jaks,

With a camera like the 5D II & shooting action/moving subjects, you need to take control of the apeture. So, the easy answer is bang up the ISO and set the apeture to the appropriate setting that you think is correct. The 5D is good at higher ISO levels. I use both a 1D iv & a 7D for all my aviation and motor racing photography. If the light is poor then the only camera to use is the 1D iv. I do sometimes put the 300mm f2.8 on the 7D & the 100-400mm on the 1D iv to compensate, if the light isn't to good. I know the 5D isn't far behind the 1D iv so don't worry about shooting at the higher ISO levels - the camera will cope just fine.

TTFN,
Neil

[briansquibb]

Re: Auto ISO

I know the 5D isn't far behind the 1D iv so don't worry about shooting at the higher ISO levels - the camera will cope just fine.

TTFN,
Neil

I am guessing that there is little in the iso performance- the 5DII is comfortable at iso 3200 - just that the AF at low light on the 5DII is a bit weak

[briansquibb]

Re: Auto ISO

The auto iso on the 7D is a "souped up" useful version of what was on older xxd EOS cameras.
On my 40D If you tried in manual it wouldn't work, it would just give you ISO 400 no matter what.
In AV or TV it wasn't much use.

I don't know what auto iso is like on a 5Dmk2 maybe others can comment.

Trev

Unfortunately the 5DII is fixed at ISO400 when on manual exposure.

The real Auto ISO on the 7D looks like a key feature when condiering an upgrade from earlier xxD bodies

[Neilly]

Re: Auto ISO

I am guessing that there is little in the iso performance- the 5DII is comfortable at iso 3200 - just that the AF at low light on the 5DII is a bit weak

I can't disagree with you there, Brian. That is one of the good points of the 1D iv its AF performance in poor light condition.
TTFN,
Neil

[briansquibb]

Re: Auto ISO

Thought I would try it as the sun came out. Greenfinch on feeder. I think it is either too slow of needs another stop/

M (1/1000, f4.0) and Auto iso (125), 400+1.4

[JaKS_Foto]

Re: Auto ISO

I am guessing that there is little in the iso performance- the 5DII is comfortable at iso 3200 - just that the AF at low light on the 5DII is a bit weak

Thanks Brian, and Neil.
I'll experiment, but methinks your are quite correct, the 5d is quite happy at 'higher' ISO settings, it's me that didn't have faith!!

Fooling around so far I'm happier now, thanks again.

[DrJon]

Re: Auto ISO

BTW I don't take my 5D2 over ISO 1600 unless I'm in extreme circumstances (read as can't get a usable shutter speed otherwise, and just have to have that) as I find too many things (DR, etc. you go from 12EV of DR at ISO 100-200 to 9EV at 3200, plus the tonal range goes from over 9 bits to under 7) so downhill too much, but that's probably just me.

[DrJon]

Re: Auto ISO

P.S. http://www.dxomark.com/index.php/Cam.../(brand)/Canon
-> measurements tab

[briansquibb]

Re: Auto ISO

BTW I don't take my 5D2 over ISO 1600 unless I'm in extreme circumstances (read as can't get a usable shutter speed otherwise, and just have to have that) as I find too many things (DR, etc. you go from 12EV of DR at ISO 100-200 to 9EV at 3200, plus the tonal range goes from over 9 bits to under 7) so downhill too much, but that's probably just me.

Clearly one sticks to the lowest reasonable iso. However far from the ideal the image doesn't offend the eyes at iso3200. However not all photos are destined for fine art pictures - look at the iso of the sports togs photos are they are far from ideal.

[briansquibb]

Re: Auto ISO

Those DxO mark measurements are interesting - do these ring true to you?

http://www.dxomark.com/index.php/Cameras/Compare-Camera-Sensors/Compare-cameras-side-by-side/%28appareil1%29/629|0/%28brand%29/Canon/%28appareil2%29/619|0/%28brand2%29/Canon/%28appareil3%29/483|0/%28brand3%29/Canon