# ISO 50



## cid (Apr 4, 2015)

Hi,

I was wondering about advantades/disadvantades of ISO 50 in photography, as far as I know it's only digitally pushed down ISO 100 ... 

are there any problem which I should keep in mind when doing landscape photography with ISO 50?

is it suitable for getting 1 stop slower shutter speed? or is better to use ND filter which has one more additional step?

thank you


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## ajfotofilmagem (Apr 4, 2015)

The only downside of ISO50 pushed digitally, the dynamic range is less than ISO100. The result is the same as shooting at ISO100, and darken the image in post production.

One advantage is that digitally push ISO100 to ISO50 (in camera, or computer) will bury the noise in the shadows.


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## sunnyVan (Apr 4, 2015)

The only time I'd consider using iso 50 is when I want to record motion I stop down as much as possible and still don't get the blur I want. And of course this is assuming I don't have ND filter with me at the time of shooting. 

Bottom line is having a less perfect shot is better than having no shot.


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## Sporgon (Apr 4, 2015)

ISO 50 on a Canon Dslr is only ETTR, that is ISO 100 over exposed by one stop and then reduced in processing. On older generation cameras such as the 5D this did result in a smoother image. However with the latest cameras the whole ETTR thing is rather moot unless you are specifically wanting to preserve more shadow detail for pushing later. 

It does lose a full stop of DR as defined in the electronic sense: I have to say that when I used to use it on a 5D for landscape I didn't notice any practical difference in DR because 8-10 stops covers nearly all the scene with the exception of what's lighting it, and then 11, 12, 13 etc doesn't add much. Shoot 16-18 stop Portra and you'd notice the difference. 

On the latest cameras I'd be more inclined to use a ND rather than over expose much, especially with blue skies etc.

When wanting low ISO on Canon it's worth noting that ISO 100 is actually ISO 80 on a 5DIII anyway.


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## cid (Apr 4, 2015)

Sporgon said:


> ISO 50 on a Canon Dslr is only ETTR, that is ISO 100 over exposed by one stop and then reduced in processing. On older generation cameras such as the 5D this did result in a smoother image. However with the latest cameras the whole ETTR thing is rather moot unless you are specifically wanting to preserve more shadow detail for pushing later.
> 
> It does lose a full stop of DR as defined in the electronic sense: I have to say that when I used to use it on a 5D for landscape I didn't notice any practical difference in DR because 8-10 stops covers nearly all the scene with the exception of what's lighting it, and then 11, 12, 13 etc doesn't add much. Shoot 16-18 stop Portra and you'd notice the difference.
> 
> ...



thank you, very explaining ... I was wondering if this option is useful in some way, but according what I read in this thread it's probably not, or in ery limiting way


And yes I knew already the base ISO for 5DkmIII is 80


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## Andy_Hodapp (Apr 4, 2015)

Using an ND Filter would be a better option to using iso 50, especially for sunsets and things where you need as much DR as possible. That being said, it's still not impossible to get some great images, here are some shots I've gotten at iso 50 when I didn't have my ND.



IMG_1541-3 by Andy Hodapp, on Flickr



IMG_1538 by Andy Hodapp, on Flickr



Madison River Pano by Andy Hodapp, on Flickr



IMG_9767 by Andy Hodapp, on Flickr


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