davidrb Loc: Half way there on the 45th Parallel

I'm wondering what that application for an ISO this low. Does anyone here use this and under what circumstances do you use it? Google search gave little information. DPReview had a minor discussion but nobody I can find uses it. It's on cameras for a reason, what might that be?

Haydon

I only occasionally use 50 when I want to extend my shutter speed even further without affecting my F-Stop for long exposures.

Bobspez Loc: Southern NJ, USA

I'm guessing but I would think lower iso = less noise, and more color saturation. Also if you raise iso in low light and/or fast shutter speeds, maybe you would lower iso in very bright light and or longer exposures.

My Kodak dcs pro 14n full frame dslr goes down to iso 80, and offers long exposure iso of 25 at 2 second or longer exposures, iso 12 at 4 second or longer exposures, and iso 6 for exposures of 8 seconds or longer. Based on that it seems lower iso was aimed at long exposures.

Fatford Loc: Rock Hill, South Carolina

In film I used to shoot ISO of 25 on occasion to get a less grainy enlargement of the pictures. I'm not sure the same applies to digital. Someone here is probably better qualified to answer.

ptcanon3ti Loc: NJ

I shoot ISO 50 EVERY TIME I do a landscape shot where I want a long exposure, this is most times I go out.

imagemeister Loc: mid east Florida

Shooting at ISO 50 makes possible the absolute best imaging performance from the sensor - just as Kodachrome 25 did in the film world ! It also enables slower shutter speeds - if that matters.

BassmanBruce Loc: Middle of the Mitten

I'm glad to see this thread as I've wondered the same. My impression has been that 100 iso is the base iso for most cameras, and thus the most optimum level to use. I thought that using 50 iso would be attenuating the image sensor data, thus worsening the signal to noise ratio. How far off am I?

imagemeister Loc: mid east Florida

It depends on the exact camera body/sensor/manufacturer .......

BebuLamar

With modern DSLR ISO 50 is generally below the base ISO and thus doesn't gain quality. However there are quite a good number of people today want to shoot wide open (f/1.4, f/1.2) most of the time (I guess to justify buying such an expensive lens) and in sunny 16 condition even with 1/8000 shutter speed you still need very low ISO and even neutral density filter.
As far as the usefulness of ISO 50. It's not that low. I used to shoot Kodachrome 25 which is ISO 25 without too much problem.

ptcanon3ti Loc: NJ

Does your camera do iso 50? If it does give it a try if conditions permit.

davidrb Loc: Half way there on the 45th Parallel

There is no right or wrong here. I just got off the phone with a Canon tech. Keep in mind this man shoots several different bodies and is very proficient with each. His response was more about technique than about technical. ISO 50 is recommended for use when needing to slow down your shutter. Long exposure shooters might have more use here than most other photographers. ISO 100 is the base setting that is recommended for most other shooting. Whatever works for you is what works for you. No need for differences of opinion it would seem.

Blurryeyed Loc: NC Mountains.

I have a Canon 6D, fastest shutter speed on that camera is 1/4000th, on bright days shooting at wide apertures for shots that need shallow DOF the camera will want shutter speeds faster than 1/4000 when shooting at ISO 100. It is my understanding that ISO 50 is a software simulation, that you are not actually shooting at ISO 50.

Rongnongno Loc: FL

Actually in this new world going to extremes of a camera sensor makes absolutely no sense what-so-ever.

In both cases you lose part of the dynamic range of your camera. Learn your camera optimal settings sensor wise then learn your lens.

From there whatever you do is your choice.

SharpShooter Loc: NorCal

Yes, this would be correct.
I beilieve there are a few cameras that have ISO of 50 as the lowest NATIVE ISO. In this case you might gain something but I believe it's been discussed that most cameras actually produce the cleanest files above somewhere above 100 but not at 100.
But for most cameras the ISO 50 is an extended range just as the super high ISO ranges are. The Camera is actually virtually approximating what the noise would look like and constructing an image digitally since the camera can't actually go to 50 natively on its own.
I have on many occasions shot sports at wide open on a bright day and the only way to control the exposure is to either use an ND or lower the ISO or both. With big lenses you may not be able to get an ND big enough, even with the big square holders.
By the way, just to show off your fancy f1.2 is a crock of crap by jealous amateurs! A pro will use what ever it takes to set their photography apart, creatively, from the guy standing next to them. By all means, take advantage of the advantage!!
Low ISO is just another tool when needed, as is f1.2, or f1.0 for that matter!! ;-)
SS

RWR Loc: La Mesa, CA

The first exposures I made with my Nikon Df was an exposure latitude test, and the only difference I could see from ISO 100 was a little increase in contrast. This is noted in the manual, which also says to use ISO 50 for larger apertures when lighting is bright.