OM-D M1: Is there a reason NOT to choose "low" ISO?

marcotronic · May 23, 2014

Hi there,

as a new owner of an Olympus OM-D M1 I'm wondering why the lowest standard ISO setting is ISO 200 and not the "low" (ISO 100?) setting. If there is enough light available - is there any good reason why I shouldn't shoot with "low" ISO setting?

I've been using several DSLRs for more than 10 years before and I'm used to shooting with ISO 100 whenever possible.

thanks a lot.
Marco

Wisertime · May 23, 2014

There is more dynamic range at ISO 200, which is considered "base" ISO....but which to use probably depends on various factors. I'll leave it to the experts to explain in more detail or you can search base ISO and find threads on it.

marcotronic · May 23, 2014

thanks a lot!

dhazeghi · May 23, 2014

marcotronic said:
Hi there,

as a new owner of an Olympus OM-D M1 I'm wondering why the lowest standard ISO setting is ISO 200 and not the "low" (ISO 100?) setting. If there is enough light available - is there any good reason why I shouldn't shoot with "low" ISO setting?

ISO Low is just ISO 200 overexposed by 1 stop, with a slightly different tone curve applied to the JPEGs. The downside is that if you blow your highlights, you're going to have a harder time recovering them - in fact they may not be recoverable at all. The upside is that you get less noise in the shadows and mid tones.

If you don't post-process, or shoot JPEGs mainly, ISO 200 is safer. If you're going for maximal pixel quality, ISO Low or ISO 200 and +1 EC are better, provided that you are careful to monitor the highlights.

Unfortunately, the histogram is based on the JPEGs, so judging the highlights can be difficult when shooting RAW (the camera tends to indicate blown highlights even in many cases when all 3 channels still have detail).

marcotronic · May 23, 2014

Thanks for the explanation. I'm shooting RAW only and process the images in Adobe Camera Raw. Have been doing so ever since

thanks again
Marco

gr8Shot · May 23, 2014

dhazeghi said:
ISO Low is just ISO 200 overexposed by 1 stop.

So you suggest sticking to ISO 200 and use the Exposure +/- for maximum flexibility? Sounds like ISO Low is just a convenience setting like scene presets. RAW shooters gain nothing since their color balance is not baked into the image and not otherwise affected. Is that it?

SpecFoto · May 23, 2014

Where I started using the low 100 setting is when shooting models in bright sun at the desert or beach. I like to shoot at as wide open of an aperture as possible with flash, and use ND filters to cut down the ambient. The low ISO 100 setting is another stop reduction that allows me to use f/1.8 apertures on the 45mm and 75mm lenses with a 4 stop ND and 1/320 flash sync speed. I am very happy with the results and the low setting has become my standard for this type of shooting.

dhazeghi · May 23, 2014

gr8Shot said:
So you suggest sticking to ISO 200 and use the Exposure +/- for maximum flexibility? Sounds like ISO Low is just a convenience setting like scene presets. RAW shooters gain nothing since their color balance is not baked into the image and not otherwise affected. Is that it?

That's what I do. I'm guessing they added ISO Low because users were complaining that the lack of ISO 100 was forcing up their shutter speeds in certain situations, like the one SpecFoto mentions below. But for RAW, you're getting the same output whether you use ISO Low or +1 exposure compensation on ISO 200.

Uncle Frank · May 23, 2014

SpecFoto said:
Where I started using the low 100 setting is when shooting models in bright sun at the desert or beach. I like to shoot at as wide open of an aperture as possible with flash, and use ND filters to cut down the ambient. The low ISO 100 setting is another stop reduction that allows me to use f/1.8 apertures on the 45mm and 75mm lenses with a 4 stop ND and 1/320 flash sync speed. I am very happy with the results and the low setting has become my standard for this type of shooting.

Excellent explanation that demands to be supported with a few photos...

Ned · May 23, 2014

Yup... your camera only has so fast a shutter speed it can obtain (ie, 1/4000s, 1/8000s, etc., depending on the body... or less if you're syncing with flash, like 1/180s, 1/250s, 1320s, etc.). If you're using a wider aperture for more isolated DOF rather than just obtaining more light, then a lower ISO allows you to keep it wide before running into your shutter speed limit. If you want more DOF however, then you can just stop down the aperture to reduce the light.

lightmonkey · May 23, 2014

http://www.cambridgeincolour.com/tutorials/dynamic-range.htm

Technical Note: In some digital cameras, there is an extended low ISO setting which produces less noise, but also decreases dynamic range. This is because the setting in effect overexposes the image by a full f-stop, but then later truncates the highlights — thereby increasing the light signal. An example of this is many of the Canon cameras, which have an ISO-50 speed below the ordinary ISO-100.

ISO100 is not 'native' to the sensor

SpecFoto · May 23, 2014

Uncle Frank said:
Excellent explanation that demands to be supported with a few photos...

Actually tomorrow I am shooting with 2 playboy models in the high desert. I will do my best to have them keep their clothes on long enough so I can post some new photos here……he.he.

barbosas · May 27, 2014

SpecFoto said:
Actually tomorrow I am shooting with 2 playboy models in the high desert. I will do my best to have them keep their clothes on long enough so I can post some new photos here……he.he.

Photos or it didn't happened

SpecFoto · Jun 6, 2014

barbosas said:
Photos or it didn't happened

Uncle Frank said:
Excellent explanation that demands to be supported with a few photos...

OK, here are a few with a bit of clothing….or not.

Hope I don't get busted for this, I tried to find some that were acceptable to this forum. All are at ISO 100.

This is the 12-40 at 40mm-f/2.8-ISO100 and 4 stop ND with FL600R at 1/2 power at about 6 feet.