Is ISO 100 on film really the same as ISO 100 on digital?

[Naboo32]

Now, this may be well be the most stupid question that I've ever asked on an Internet forum, but I know that if I don't ask and then something goes wrong with my 'cunning plan', I will be very annoyed with myself :bang:.

So, here's the thing; I want to shoot a roll of Velvia 100 through my Nikon FA (with it's lovely 'Matrix' metering ), but I know that colour slide film is very short on exposure latitude and so I must get it right first time (bracketing is a very expensive option and nearly 10 quid a roll + processing ). My 'cunning plan' is to take my D700 along with me and simply make the best digital exposure that I can, using the same subject and lens, then simply take the settings from the D700 and 'copy' them into the FA (35mm SLR) and make the film shot that way (as long as the ambient light is stable, of course ).

What I'm wondering is, provided that I dial in 'LO -1' (or whatever the Nikon expression of ISO 100 is on the D700), will my exposure on film exactly match that of the digital version (assuming that the lab can process it properly)?

As far as I can work out, it should , but I wonder if anyone else has tried this and has any comments. Have I missed something? I have a terrible feeling that I have .

Thanks!

Andy

 

[AJQS]

It should be fine, but it won't match exactly simply because digital is nice and linear, film isn't

 

[simonblue]

I would just use the metering in your FA,for years before Digtal we used to get our exposures right from non digtals cameras

 

[srichards]

Take a lightmeter with you too.

 

[freecom2]

People managed, meterless, with transparencies like Kodachrome and other slide film. You'll be fine. The baseline exposure should match well enough.

 

[Naboo32]

It should be fine, but it won't match exactly simply because digital is nice and linear, film isn't

Oh thanks, Alan! A nice unbiased reply there .

Take a lightmeter with you too.

A what now ? Is that like some kind of torch :shrug:?




Seriously, thank you all for your replies. Part of the reason for wanting to take the D700 along is so that I can compare the scans from the Velvia to the digital capture, both for colour rendition and for sharpness/image quality. I thought that it would be a fun experiment to have identical exposures on both formats , so the question is whether or not to use the meter of the FA, or make the exposure on the D700 first and try and match it to the film camera :shrug:. Of course, a lot of it will depend on how the lab process the film, but I was simply wondering if (say) 1/50th sec @ f/8 through a 50mm prime lens on ISO 100 Velvia will have the same exposure 'look' to it as 1/50th sec @ f/8 on the same 50mm prime fitted to the D700 set at ISO 'Low' ?

I can't think of any reason why not, but from what some of you have said, it shouldn't make much difference. I was just a bit scared by what I'd read elsewhere on the Internet about colour slide film being 'criticial' within +/- 1/3 of a stop .

Oh well, I'll get and tomorrow and find out for myself .

Cheers again for the replies!

 

[Joenail]

I've been using my digital to meter 5x4 Velvia recently and it varies from being a half a stop to a full stop under. Digital will rarely transfer perfectly over to film, so I'd advise that you use your FA's meter. Or do a test roll, bracketing in half stops, to find out how close it is.

Velvia is definitely usable when exposed a stop out, though, if you're scanning or viewing on a lightbox. You should be fine whatever you do really

 

[Naboo32]

I've been using my digital to meter 5x4 Velvia recently and it varies from being a half a stop to a full stop under. Digital will rarely transfer perfectly over to film, so I'd advise that you use your FA's meter. Or do a test roll, bracketing in half stops, to find out how close it is.

Velvia is definitely usable when exposed a stop out, though, if you're scanning or viewing on a lightbox. You should be fine whatever you do really

Hi Joe,

I caught this post just in time, as I am about to head off (a little later than planned), to take some photos.

It's great to hear from someone who's actually tried doing this already and seems to confirm the nagging doubt that I had about DLRs and SLRs not all necessary 'seeing' a scene the same way. I can remember reading something like this, a long time before I started messing around with film.

Anyway, I think that I will just try and 'wing it' for today's exposures, by using the FA's meter (as everyone else has suggested too) and if I don't shoot off the whole roll I will use the last few exposures to make some comparison shots. At least that way my camera bag will be lighter this morning .

Thanks for the advice!

 

[excalibur2]

Anyway, I think that I will just try and 'wing it' for today's exposures, by using the FA's meter (as everyone else has suggested too)

........assuming the FA has been checked for accuracy but I was interested in the question as I don't own a proper digital camera and in my logical assumption:- Light is light whether you read the exposure setting from any type of accurate light meter, so if a digital camera gives an exposure from a Kodak Grey card, that should work using film (if the scene/subject is Kodak Grey).
BTW Colours can't be seen by a light meter so all colours are shades of grey.

 

[Naboo32]

........assuming the FA has been checked for accuracy but I was interested in the question as I don't own a proper digital camera and in my logical assumption:- Light is light whether you read the exposure setting from any type of accurate light meter, so if a digital camera gives an exposure from a Kodak Grey card, that should work using film (if the scene/subject is Kodak Grey).
BTW Colours can't be seen by a light meter so all colours are shades of grey.

Well Brian, I've shot a couple of rolls of b&w film through the FA and the 'Matrix' metering does a pretty amazing job on its own, most of the time. That said, I'm just scanning the negs and they always tend to come out of the scanner lacking contrast, so I have to fiddle about with the curves a lot later .

Since colour slide film is less 'forgiving' than b&w print film, I was concerned that exposures which were a stop or so off (but easy to fix in PP) when using b&w film, might be totally washed out looking or way too dark with slide film :shrug:.

Anyway, there's no substitute for personal experience, so I'm just shooting through this first (ever) roll of Velvia with the FA's meter and adding + or - EV comp where I can be certain that some is required (although just how much is another story ).

It's a bright and sunny day here in Germany today (the perfect setting for Bayern to thrash Chelsea later on ) with some scattered cloud. I shot 18 exposures (mostly colourful flowers and some scenes from the local cemetery) in fairly direct sunlight. I don't know if that was wise, as my DSLR can only produce extremely 'washed out' looking colours in such settings (although my eyes can see more colour). I plan to try and shoot the other 18 frames this evening, although living in the city, there's nowhere that I can go to see the Sun set on the horizon .

After that, it's off to the lab for my 'little roll of hope' . It's funny, Fuji Velvia has such a 'legendary' status, that I feel a little inimmidated by it . I think nothing of shooting off a roll of Acros 100, but this is somehow different :shrug:.

Anyway, I hope to share the results in the 'Film' part of the forum, in due course.

 

[excalibur2]

Looking forward to your shots esp flowers as with Fuji neg film I can't seem to get a dark red/maroon rose looking right, and someone said (who uses plenty of slide film) Velvia would give better results.

 

[Joenail]

Light is light whether you read the exposure setting from any type of accurate light meter, so if a digital camera gives an exposure from a Kodak Grey card, that should work using film

Actually no, I think you're wrong there. Digital meters to 18% grey, film to 12%. Could be the other way round, I'm not too sure, but they're definitely different.

 

[s162216]

Actually no, I think you're wrong there. Digital meters to 18% grey, film to 12%. Could be the other way round, I'm not too sure, but they're definitely different.

Officially its defined as about 12% grey by ANSI (who's standards Japan follows) but in practise there is no set standard for what any meters are calibrated to, it even varies across companies with Canon USA apparently claiming their calibrated to 18% grey but the actual engineers in Japan saying their done to ANSI standards (~12%). Sekonic meters are officially calibrated to 14% and Minolta spot meters were to about 15%.
In practise it doesn't make much of a difference because if you actually read the instructions for a Kodak R-27 grey card set it specifically states to open the aperture 1/3rd of a stop extra for subjects of normal reflectivity which would cancel out the difference in what the meters are calibrated to. Its uncertain why 18% was originally chosen by Kodak for their grey cards back in the 1940's, even they claim to not know!

 

[excalibur2]

Officially its defined as about 12% grey by ANSI (who's standards Japan follows) but in practise there is no set standard for what any meters are calibrated to, it even varies across companies with Canon USA apparently claiming their calibrated to 18% grey but the actual engineers in Japan saying their done to ANSI standards (~12%). Sekonic meters are officially calibrated to 14% and Minolta spot meters were to about 15%.
In practise it doesn't make much of a difference because if you actually read the instructions for a Kodak R-27 grey card set it specifically states to open the aperture 1/3rd of a stop extra for subjects of normal reflectivity which would cancel out the difference in what the meters are calibrated to. Its uncertain why 18% was originally chosen by Kodak for their grey cards back in the 1940's, even they claim to not know!

...and all that and how accurate is the shutter speed also the F stops on an older (or new) camera/lens :shrug: and also throw in slight human error which could all compound for an over/under exposure

 

[robhooley167]

My 5Dmk2 gives me results within 1/3 of a stop of my Gossen lightmeter and one of my metered film bodies, so i imagine a D700 would do similarly, i believe Woodsy tried with his and got the same sort of accuracy as me.

In short, it will do the job fine, but i would consider getting a dedicated lightmeter as they tend to be a lot lighter than a D700 with lens

You could however use the D700 as a digital polaroid

 

[Naboo32]

Hmm, quite a can of worms that I've (unwittingly) opened here .

Thanks a lot to everyone who replied and gave me something to think about . I have decided that I will wait and see how the results from my Nikon FA (set to 'Matrix' metering) come out, before making up my mind whether or not to shoot any more slide film.

A light meter would be an unnecessary extravagence for use with the b&w print film that I normally shoot, so I'll postpone a decision on that one for now .

 

[dalex_257]

It is not the same as film - digital definition of ISO is somewhat strange. In addition to that if you are going to be relying on in camera (DSLR) meter to set film exposure, then you more likely need to resort to spot metering mode (as it is scene independent and therefore more consistent) and understand how it is set for your camera in relation to film (i.e. whether you can use exposure settings from it directly or need to add some correction to them). I would suggest this article as a starting point about DSLR exposure meter calibration. Basically the thing is that on different DSLR models meters will make the exposures differently with respect to giving you that exposure lattitude (which is where the blown highlight restoring comes from). So calibration is about establishing the gray point of the camera meter (what it is set to and on what ISO - as it can differ when in camera ISO goes up) and how it translates to the one you should use on film.

 

[Alastair]

I've shot Ektar side-by-side with digital (40D and sanity checked against the Fred Parker tables - it was long exposure at night) and the results are broadly comparable using identical settings, certainly within 1/3 of a stop to my eyes.

You could halve your costs (or better) of the trial by using short-dated prepaid slide film from Boots. I think the rolls I have were about £3 each (prepaid developing too).