Iso vs lens speed

[leica1215]

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I'm considering the 28/1.4 vs 2.0 , wondering what is the ratio speed vs Iso?

 

From 2.0 down to 1.4 how much iso I have to compensate ?

 

Thanks

 

 

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[Mute-on]

One stop. 

 

Therefore, f 2.0 at ISO 200 is equivalent to f 1.4 at ISO 100 in exposure. At any given ISO, moving from f 2.0 to f 1.4 will require halving the ISO. So 1600 becomes 800, 800 becomes 400, and so on.

 

An f 2.0 lens would be considered fast for daylight photography. Shooting at dusk or by artificial light, the extra stop of f 1.4 may provided some benefit, but this can be easily compensated for by one stop higher ISO and a steady hand. 

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[jaapv]

Aperture stops on a lens will increase/decrease the EV  the same as shutterspeeds or ISO value steps.

 

The 28/1.4 is only worth its money if you have a clear idea of its  use, which is not specifically low light photography. On a modern camera 2.0 is ample for almost all low light work with a 28 mm lens, Its real value lies in the combination of a wideangle lens and shallow DOF.

[leica1215]

Thanks, what about increase EV will it affect the quality of the picture? The shutter speed and Iso seem more often to adjust.

 

 

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[Printmaker]

Anything higher than the base ISO decreases image quality. At 2x the base what you will see is a slightly lowered dynamic range. At 4x (2 stops) you will see an even larger decrease in dynamic range and noise in the shadows which looks a bit like film grain.

 

In practical terms, you can shoot a Monochrom at up to ISO 3200 without suffering a significant decrease in quality when printing at sizes up to 13x19 inches. Unless of course you are very fussy, in that case 1250/1600 should be your top ISO.

 

Personally, I like the look of high ISO Monochrom files. They have a film-like look. I have no problem shooting at ISO 3200 with my 50 Summicron.

[IWC Doppel]

Are you talking MM1 or MM2 ?

[Printmaker]

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Are you talking MM1 or MM2 ?

 

MM1 but the same holds true for the MM2 but plus a stop. At least as far as the tests I've seen. I only have a MM1.

[IWC Doppel]

I tend to use ISO 1600 in the evening with my MM1

I've also taken to setting my M-9P at 320 during the day which makes swapping cameras easier even though I meter, I just get used to 1000 ish n f4 sort of day

[Geoffrey James]

I regularly use 1250 on the MM1 and have no problems with larger prints up to 36 inches.  I find the so-called loss of dynamic range to be similar to the diffraction problem after f5.6,  which is to say,  discernible to those who use magnifying  glasses or screen magnifications, rather than looking at actual prints in real-life situations.