M9 ISO 400 Latitude?

[Pioneer]

I have an odd question. There may not be an answer because most people wouldn't have normally bothered.

Lately I have been shooting my M9 with the back screen and other controls covered. To be able to do this I arbitrarily set the ISO at 400. I also set the format to DNG so that it works like a digital negative. (Don't ask!)

My question is this. If the ISO setting is at 400, how far can I actually "push" the exposure and still recover things in Lightroom?

In other words, if the ISO is set to 400 can I actually expose at EI800 or EI1600 and still recover the image?

Ah well...misspelled latitude. Drat, do that all the time!

 

[rscheffler]

A couple years ago there was extensive investigation regarding the pushability of M9 DNG files over on LUF, FM and by bloggers, such as Jim Kasson

In a nutshell, there is virtually no benefit to setting ISO higher than 160. Results from pushing DNGs multiple stops were as good or better than the camera's internal process. Though I believe Kasson found there was a slight measurable benefit from setting in-camera ISO up to 640, in real world use, it likely won't make a difference. Above 640 he found the camera's internal process was inferior to pushing ISO 640 or lower DNGs in post.

Setting the ISO to 160 and whenever possible trying to correctly expose for that value means the widest dynamic range possible from the sensor. Setting to ISO 400 reduces it by about a stop. As Tom points out, if you don't err on the side of underexposure, the M9 is pretty unforgiving with clipped highlights (which I guess you already know).

Naturally, the more you push files the noisier the images will be. Pretty much like shooting the M9 at ISOs 1600-2500. But it shouldn't be worse than if the camera was set to that ISO range.

 

[V-12]

In other words, if the ISO is set to 400 can I actually expose at EI800 or EI1600 and still recover the image?

Usually yes, under exposing with the M9 is vastly better than over exposing and there is always far more in the shadows to recover than from blown highlights. This is true even if you could see the LCD screen because you need to make a leap of faith in the M9 as the LCD is so poor (by modern standards), and you can't always appreciate from a quick look what you have recorded, the histogram is a much better guide. What you need to be aware of when going from 400 to under exposing by two stops at EI1600 is the possibility of banding in the shadows.

V

 

[Doug]

As an experiment, I've recently been setting to Auto ISO with a max of 800 and setting Exposure Compensation to -1 stop. Worst case would end up the equivalent of 1600 then. This is in the interests of protecting highlights. I don't look at the screen much, might be workable to cover it!

 

[Pioneer]

Usually yes, under exposing with the M9 is vastly better than over exposing and there is always far more in the shadows to recover than from blown highlights. This is true even if you could see the LCD screen because you need to make a leap of faith in the M9 as the LCD is so poor (by modern standards), and you can't always appreciate from a quick look what you have recorded, the histogram is a much better guide. What you need to be aware of when going from 400 to under exposing by two stops at EI1600 is the possibility of banding in the shadows.

V

This is basically why I am playing with this. I really love the M9 images but I have been bit a number of times by using the display screen during shooting.

Somewhat inspired (or perhaps driven to insanity) by the idea of the Edition 60, I decided to just go completely without my display. I set auto white balance, ISO 400 and DNG format and slapped a big piece of gaffers tape across the back panel.

Now I am shooting like it is a digital film camera with ISO 400 film. Ninety percent of the time ISO 400 works great but tomorrow night I will be photographing a softball game under the lights. With TriX or HP5+ I would just photograph at EI1600 and develop accordingly.

Sounds encouraging from what everyone is saying. I guess we will see after tomorrow. 🙂