K5 - ISO 80

Literal Humour! - love it

Had to look that one up Smeggy!
DXO Some shout about it, some at it...
A double (entendre) edged sword...

Not in the case of the K-5.

As the DxOMark results show, the K-5 gains dynamic range at the ISO 80 setting.

Older Canon cameras had ISO 50 settings, which just decreased dynamic range by crushing shadows but not by making the sensor less sensitive.

BTW, most cameras have a highest ISO setting (ISO 1600 in the case of the K-5) which benefits (slightly) from internal analogue amplification. Higher ISO settings are achieved by digital upscaling and could just as well be achieved in post. The advantage of the post scaling is that losing highlights is less likely, but one then has to deal with explicit post processing and underexposed shots on the back LCD.

DR is best at lower ISOs so ISO100 is where the K5 starts (before enabling the extended range) but I know that ISO80 is where landscapers want to be .... and like Smeggy I turned on the expanded range to ISO 80 almost as soon as I switched it on.

I think all 'pro' testing agencies/magazines etc. also test at ISO100 for that same reason, DR diminishes as you go higher.

I think in practise the difference between 80 and 100 is negligable. But the answer is simple. Just take some pics with both settings and see if you can a] tell the difference and b] if you can is it worth worrying about?

With the K-5 I never worry too much about ISO These were done at 32000 and 12800. I obviously wouldn't use them for a serious landscape though.

Hi all,

Dynamic range drops on all digital cameras as you turn the voltage (ISO control) up.

I too have the in camera 'improvements' on and therefore base 160 is the result. Compared to early days of digital, blown out skies in landscapes are rarer, shadowed areas are more detailed and noise levels are extraordinarily low.

I agree with all the comments that it is what you take that matters. I also think too many people now think a 'good' photo is one that looks great on their 96 dpi monitor (72 on a Mac) rather than a large print.

I only ever look at my pics on a computer monitor. Am I contributing to the number of "too many people" ?

Hi, apologies if I upset any one.

We are producing very high quality images and critically analysing them on very low resolution RGB screens. IF at some stage the high resolutions Apple are now putting in their mobile devices (they call it Retina Display we can call it print quality) make it to our PC's and laptops then we will have a closer comparison with large prints.

Having seen pro exhibition work at A2 and above from 35mm size sensored cameras I've been made aware that what we see on screens isn't the full picture (so to speak)

There is indeed a huge difference between a monitor image and an A3 print. Few of us will ever print to A2.

The print medium is far more demanding and reveals all sorts of defects. If though we never print and only view on the monitor and on the web, then that's a whole new ball game. We may not need more than a 6MP camera for that, and possibly less if there's not much cropping to be done.

Compacts and even mobile phones can produce very acceptable web images, given the right conditions and the right photographer.

It is much easier to use a DSLR though, I find it so anyway.

There is an argument that I tend to agree with that it doesn't actually matter how big you print, the quality remains the same!

Yes, it does sound counter-intuitive but if you think about it it makes sense. We tend to stand at a distance that allows us to see all of the image (which follows the square rule) so if you go from 10x8 to 20x16 or A4 to A2 you stand twice as far away so it still 'seems' to be the same size, therefore appearing to be the same quality.

And if you don't believe me, get up close to an advertising billboard. It is made up of huge spots of colour, but you don't normally notice because you stand a long way away.

Which is why nobody really needs more than about 10 megapixels!

The basic point is right, providing of course we do actually change our viewing distance. The resolution of 35mm film is about right for a 16"x12" print, so whatever that equates to is the right number of MP.

I'm still very new to all this but it sounds like you are saying if I dial in iso 100 or 200 etc the camera still decides what's best Sorry if this sounds a bit daft

I'm no expert on this aspect, but my understanding is that there is a "native" level and all other ISO values are obtained by turning the "volume" up or down. The native level of Pentax DSLRs I understand to be ISO 200.

There will indeed be a sensitivity where the gain is at 0. upto a certain ISO level the gain will be increased before the Signal is digitiszed and for ISOs above this level the signal gain will be increased digitally.

Applying a positive gain to amplify low level light increases the noise level and thus decreases the dynamic range.

Applying a negative gain ( turning the volume down ) to avoid overloading the sensor with light will also decrease the noise level. but this only work upto a point as the signal chain post gain change will have a certain noise floor and this will limit how much you can turn down the noise overall.

ALL ISO settings are achieved by electronic 'wizardy' all of the the time. - the 'native' level is just a gain setting of zero. it's still achieving this by electronic means