Auto ISO setting problem

[Eugene Young]

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This may be a dumb question because I  first tried Leica M . I chosed auto iso setting  and assigned shutter speed at 1/4f and max iso at 50000  for my M11with 35 lux.

During night shooting test the camera overrided the auto iso setting and assigned slower shutter speed 1/15 or 1/40 with max iso 50000.

I am wondering whether I made a mistake or the camera is broken.

[SrMi]

If you hit the Auto-ISO max limit, the shutter speed will be reduced to keep the image properly exposed.

AFAIK, that is how Auto-ISO is implemented for most (all?) cameras.

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[Jewl]

vor einer Stunde schrieb SrMi:

If you hit the Auto-ISO max limit, the shutter speed will be reduced to keep the image properly exposed.

AFAIK, that is how Auto-ISO is implemented for most (all?) cameras.

I dont think this is implemented in the same way for the Q for example. When I remember correctly, the Q will never go down below the min. Shutter speed as configured even the picture might not be properly exposed! Was also very confused when I got my M10 behaving not like this for the first time!

Edited May 29, 2022 by Jewl

[SrMi]

4 minutes ago, Jewl said:

I dont think this is implemented in the same way for the Q for example. When I remember correctly, the Q will never go down below the min. Shutter speed as configured even the picture might not be properly exposed!

I checked with Q2, and it behaves the same as M11. Can you check if Q works differently?

[Jewl]

vor 56 Minuten schrieb SrMi:

I checked with Q2, and it behaves the same as M11. Can you check if Q works differently?

Okay then at least it got consistent. Unfortunately I sold the Q1 therefore cannot check with the latest fw! Sorry!

[Stef63]

8 hours ago, Eugene Young said:

This may be a dumb question because I  first tried Leica M . I chosed auto iso setting  and assigned shutter speed at 1/4f and max iso at 50000  for my M11with 35 lux.

During night shooting test the camera overrided the auto iso setting and assigned slower shutter speed 1/15 or 1/40 with max iso 50000.

I am wondering whether I made a mistake or the camera is broken.

Hi Eugene,

What do you expect from the camera if light conditions are so low that the combination of what you demanded - iso 50000 and 1/140s (4x35) - is not sufficient for a proper exposure? There are only three options here :

1) decrease the shutter speed although you (the photographer) demanded for 4x focal length

2) elevate ISO above 50000, although you demanded max 50000 to avoid high iso noise

3) underexpose the capture 

There is no magic here, nor is there something wrong with your camera, but it is clear that Leica took the best option of the three and that is nbr 1.

[lct]

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Not sure why getting a photo ruined by motion blur would be a better option than a photo still usable with more digital noise. The critical choice here is that of the camera to reduce the shutter spead instead of increasing the maximum iso IMHO.

[SrMi]

The max ISO setting of Auto-ISO should be set to the maximum available ISO if one prefers more noise to slower shutter speeds,
Once the max ISO has been reached, the resulting image may look better with motion blur than with several stops underexposed at max ISO.

[Eugene Young]

Thank you all for quick response. Now I almost but not quite all understood auto iso setting. The problem remained during night shooting is that the camera assigned max iso and much slower shutter speed so made overexposure and increase a risk of camera shake. 

 

[adan]

The Leica M does have the nice little feature called a dedicated shutter speed dial on the top.

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To guarantee a fast-enough shutter speed in AUTO-ISO mode - set that dial manually to 1/250th or 1/500th second, or whatever is needed/desired. The camera will use that speed, no matter what the lighting is, compensating exposure with the AUTO-ISO.

I do this regularly when using a 21mm (where 4x = 1/84th sec. - still not enough to freeze active subject matter - kids, dancers, rock musicians). Or a 28mm (1/112th sec.)

[Eugene Young]

 Mr. Adan!

Thank you for kind advice🙆‍♂️

[lct]

10 hours ago, adan said:

To guarantee a fast-enough shutter speed in AUTO-ISO mode - set that dial manually to 1/250th or 1/500th second, or whatever is needed/desired. The camera will use that speed, no matter what the lighting is, compensating exposure with the AUTO-ISO.

Never been in that situation but i would expect the camera won't override isos then and the pic will be too dark, unless i'm missing something as usual .

[Stef63]

3 hours ago, lct said:

Never been in that situation but i would expect the camera won't override isos then and the pic will be too dark, unless i'm missing something as usual .

Nope.  You are not missing something.  Just tested it with Auto ISO set at max 8000 and shutter speed 1/1000 for an indoor picture.  Picture was indeed taken with ISO 8000 and at 1/1000 and is now 100% black…

Again no magic here and totally according the choices Leica made, whether they are good or bad.  ISO max in Auto ISO is a hard stop.  Shutter speed limit has no hard stop when in Auto.  If you set the shutter yourself, ISO max is still a hard limit, exposure stays at the preset level and underexposure can occur of lighting conditions are low. 

[darylgo]

8 minutes ago, Stef63 said:

 is now 100% black…

A sharp image without exposure sounds less satisfying than a blurred image.  🙂

When I test this on my M10 series, the viewfinder indicators on both the visoflex and rangefinder eyepiece show that an underexposure will occur.  Similar to other auto settings it is easy to rely on the camera to set what we think is best, yet it doesn't.    

[adan]

2 hours ago, darylgo said:

A sharp image without exposure sounds less satisfying than a blurred image.

I suppose it depends on the definition of "satisfying."

The picture below was made 45 years ago, in conditions equivalent to the one under discussion here. Light so dim the meter said no correct hand-held exposure was possible (actually the meter could barely read the light at all - I had to extrapolate). And therefore the meter had to be ignored.

Nikon F, 28mm f/3.5 Nikkor-H at a barely-hand-holdable 1/15th second on Tri-X - the meter said it would still require ISO 8000 (at least!). So I cooked it in Acufine. Still a very thin negative, so I printed it on grade 5 Brovira, with lots of dodging and burning. The neg:

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Some may not be impressed with it - but enough people were impressed with it that, as part of a documentary project on a dirt-track racer, it:

1) earned a top grade in my college documentary photo class

2) became part of my first published magazine photo story (the picture ran across two pages out of 10)

3) became part of the portfolio that gained me other photo jobs, and eventually full-time employment as a photographer, entrance to graduate school, and a lucrative and creative lifetime career.

I have found that extremely satisfying.  

[lct]

5 hours ago, Stef63 said:

Nope.  You are not missing something.  Just tested it with Auto ISO set at max 8000 and shutter speed 1/1000 for an indoor picture.  Picture was indeed taken with ISO 8000 and at 1/1000 and is now 100% black…

Again no magic here and totally according the choices Leica made, whether they are good or bad.  ISO max in Auto ISO is a hard stop.  Shutter speed limit has no hard stop when in Auto.  If you set the shutter yourself, ISO max is still a hard limit, exposure stays at the preset level and underexposure can occur of lighting conditions are low. 

That's what i expected but auto iso can work in manual mode if needed. In your example you can set max iso to 50,000 for instance so that the camera will choose the right iso up to 50,000 depending upon aperture and shutter speed you've set. If 50,000 is too high for you suffice it to open aperture and/or reduce shutter speed accordingly. But i have nothing to teach you of course just sharing my practice of auto iso + M mode with other cameras than the M11 but i guess it works the same way on the M11.

Edited June 1, 2022 by lct

[darylgo]

8 hours ago, adan said:

I suppose it depends on the definition of "satisfying."

The picture below was made 45 years ago, in conditions equivalent to the one under discussion here. Light so dim the meter said no correct hand-held exposure was possible (actually the meter could barely read the light at all - I had to extrapolate). And therefore the meter had to be ignored.

Nikon F, 28mm f/3.5 Nikkor-H at a barely-hand-holdable 1/15th second on Tri-X - the meter said it would still require ISO 8000 (at least!). So I cooked it in Acufine. Still a very thin negative, so I printed it on grade 5 Brovira, with lots of dodging and burning. The neg:

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Some may not be impressed with it - but enough people were impressed with it that, as part of a documentary project on a dirt-track racer, it:

1) earned a top grade in my college documentary photo class

2) became part of my first published magazine photo story (the picture ran across two pages out of 10)

3) became part of the portfolio that gained me other photo jobs, and eventually full-time employment as a photographer, entrance to graduate school, and a lucrative and creative lifetime career.

I have found that extremely satisfying.  

Great image, I remember those days of using tri-x at  football games.  Iso 1600, 1/125th @f3.5 and best to shoot the running back coming straight at you to see his face and get the least motion blur.   Thin negs, muddy images but at least one good frame.  I also remember leaving the games with a headache from peering through the Nikon F viewfinder for hours.  Iirc, soon after those early 70's days GAF or 3M brought out a crazy iso 1000 pushed color reversal film that was used by many for concerts, the results were horrible color, grain clumps as big as sprocket holes but the images were quite good nevertheless.  

 

Edited June 1, 2022 by darylgo