Questions About ISO LO1: My Nikon Df has a base ISO of 100, but the ISO dial allows me to go below below 100 in 1/3 increments to LO1. From what I've read online I think that LO1 would...

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

My Nikon Df has a base ISO of 100, but the ISO dial allows me to go below below 100 in 1/3 increments to LO1. From what I've read online I think that LO1 would be one stop below the base ISO, which would make LO1 ISO 50. But if that is the case why is it marked LO1 and not 50?

Also are there any negative effects to IQ in shooting below the base ISO?

BebuLamar

They marked Lo1 because they don't recommend it unless you have to because whatever you shoot is just too bright. IQ is somewhat lower than the base ISO 100.

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

BebuLamar wrote:

They marked Lo1 because they don't recommend it unless you have to because whatever you shoot is just too bright. IQ is somewhat lower than the base ISO 100.

Thank you Bebu.

RWR Loc: La Mesa, CA

Mac wrote:

My Nikon Df has a base ISO of 100, but the ISO dial allows me to go below below 100 in 1/3 increments to LO1. From what I've read online I think that LO1 would be one stop below the base ISO, which would make LO1 ISO 50. But if that is the case why is it marked LO1 and not 50?

Also are there any negative effects to IQ in shooting below the base ISO?

See page 71 in the User’s Manual. Rather than degrading the IQ, the bit of increased contrast at ISO 50 (Lo 1) is often a plus.

Steve Perry Loc: Sylvania, Ohio

The "Lo" setting actually allows the camera to overexpose the image, which it then takes and pulls back down. However, it's not a free lunch - it can easily clip highlights. It's exactly the same as you adding exposure to the image and pulling the resulting overexposed image down in post.

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

RWR wrote:

See page 71 in the User’s Manual. Rather than degrading the IQ, the bit of increased contrast at ISO 50 (Lo 1) is often a plus.

Of course, RTFM. I looked online, but not in the manual.
Thanks

Mac Loc: Pittsburgh, Philadelphia now Hernando Co. Fl.

Steve Perry wrote:

The "Lo" setting actually allows the camera to overexpose the image, which it then takes and pulls back down. However, it's not a free lunch - it can easily clip highlights. It's exactly the same as you adding exposure to the image and pulling the resulting overexposed image down in post.

Thank you Steve, a great explanation.

RWR Loc: La Mesa, CA

Mac wrote:

Of course, RTFM. I looked online, but not in the manual. Thanks

I bought a Df to replace Polaroid film, and since I shoot Velvia 50 Lo 1 was one of the first things I checked out. It’s not for snapshots - in the proper lighting there will be no highlights to clip.
Edit: I really should amend that last statement. Properly interpret the meter reading, there will be no danger of clipping highlights.

selmslie Loc: Fernandina Beach, FL, USA

Mac wrote:

My Nikon Df has a base ISO of 100, but the ISO dial allows me to go below below 100 in 1/3 increments to LO1. From what I've read online I think that LO1 would be one stop below the base ISO, which would make LO1 ISO 50. But if that is the case why is it marked LO1 and not 50?

Also are there any negative effects to IQ in shooting below the base ISO?

Lo 1 is the same as overexposing ISO 100 by one stop.

You gain one stop of DR at the dark end at the expense of losing one stop on the high end.

The only danger would be if you already are close blowing the highlights at ISO 100.

JD750 Loc: SoCal

Mac wrote:

My Nikon Df has a base ISO of 100, but the ISO dial allows me to go below below 100 in 1/3 increments to LO1. From what I've read online I think that LO1 would be one stop below the base ISO, which would make LO1 ISO 50. But if that is the case why is it marked LO1 and not 50?

Also are there any negative effects to IQ in shooting below the base ISO?

(1) Nobody understands why Nikon labels functions and camera models the way they do.
(2) Hmm. Good question. Nikon would not include it if it was gong to be crap. Why not shoot some images with both settings and compare. Post the results here?

1963mca

The label LO1 causes you to stop and think..... Do I really understand what this is and do I want to use it? If they just labeled it 50, then uninformed uses would just use it thinking it was a true 50 and then be upset with Nikon when the image might not appear as expected.

lamiaceae Loc: San Luis Obispo County, CA

With my Pentax K-5 camera it is called Expanded Sensitivity, for ISOs from 80-100 < Normal (200-12800) > 12800-51200. Base exposure is ISO 200.