Standard Exposures

[Mike Green]

Hello all

I'm relatively new to large format and have a beginners question that I can't seem to find an answer to anywhere else. I am shooting 4x5 on a Linhof Kardan Color 45s and a Super Graphic, both of which I find fascinating to use and my early results have been a mixture of disappointment and awe.

Being at this moment unable to afford a spot meter I tend to do the best I can with the metering from an SLR but it's not ideal. I've seen standard exposures for various scenes - sunny 16 etc. What I was wondering though is this:

If I'm looking at the ground glass and I can see my image fairly clearly in the available light at f5.6 - what exposure for say Velvia or Delta 100 would I need for the image to appear on film exactly as I see it on the groundglass? Could I use that as a starting point to calculate exposure? Or are there too many variables to do this accurately?

Thanks

Mike

[Mike Green]

Sorry - I realise the title of this post was a bit vague

[Jim Rice]

That won't work, however the SLR as meter should do okay.

[Mike Green]

Thanks Jim - could you elaborate at all? I'm sure there's a good reason why it won't work, but I haven't shot enough film to really understand it.

I figured if you know the sensitivity of a particular film to light and how it compares to the eye viewing the ground glass image that it would be possible to work out a base equivalent exposure. I'm sure I'm missing something, I just don't know what.

[Ken Lee]

Using a camera as a light meter - and as long as you are focused fairly close to infinity - your exposures should be pretty close. 1/60 at f/11 is the same, wherever we go.

That is... as long as you are using a "prime" lens on the SLR. A zoom lens changes effective f/stop as you zoom in and out, and the meter compensates for you, as it were. What it says is f/8, may vary with focal length.

Also: If you start taking close-ups, where the bellows extension gets long, then the distance from the lens to the film becomes a factor. At 1:1, you need an extension of twice the focal length. For example, a 150mm lens needs 150mm extension at infinity, but will need 300 mm of bellows draw, to focus at 1:1.

With double the bellows extension, you get a giant image circle: twice as large as at infinity. A circle of twice the diameter, is 1/4 as bright. Hence you need to open 2 f/stops to shoot at 1:1.

However, for distance objects, this doesn't matter.

[PViapiano]

I would just use the sunny 16, and see if that works for you.

Google for the Ultimate Exposure Computer...a listing of film speeds, times, apertures for a zillion different situations. A good one to commit to memory...

[Mike Green]

Thanks PViapiano - that looks very useful.

Ken - thanks. It was actually a macro shot that got me thinking about it. I was shooting a flower with a 65mm lens extended to around 230mm. I took two shots and calculated the exposure from a reading off another camera which came out fine. But as I was focusing I could see the flower quite clearly on the ground glass maybe a stop or two lower than I wanted and I just wondered if there was a simple way to work out the exposure from that without metering. Guess I'm probably just being awkward when there are already so many methods that work.

[BradS]

As others have said, the meter in your 35mm SLR should suffice. I have used the meter in a Nikon FA to meter scenes that I ultimately shot with the 4x5. I see absolutely no reason that a large format view camera would require the use of a spot meter....a simple hand-held incident / reflected meter ought to suffice. The only down side to using the meter in the 35mm SLR is , of course, the extra weight.

[Mike Green]

Thanks for the reply Brad - sorry I think I was a bit vague but I actually had quite a specific question. I probably shouldn't have written the middle paragraph. I didn't mean to ask generally how should I meter my shots, but specifically - is there an exposure setting which for a given film will always capture the scene exactly as you see it on the ground glass. It seems there probably isn't, but I don't really understand why.

[BradS]

Thanks for the reply Brad - sorry I think I was a bit vague but I actually had quite a specific question. I probably shouldn't have written the middle paragraph. I didn't mean to ask generally how should I meter my shots, but specifically - is there an exposure setting which for a given film will always capture the scene exactly as you see it on the ground glass. It seems there probably isn't, but I don't really understand why.

I think the probelm is that our eyes (and the brain behind them) are doing too much processing on the light level to give an objective value. Does that make sense?

In other words, it probably could be worked out in theory - up to the "exactly as I see it on the ground glass" part. Our brains do too much adjusting of the perceived image.

However, if you were to take a simple incident reading off the ground glass, then there would certainly be some simple relationship between the light reading from the GG to the actual camera settings to achieve proper exposure. This is, of course and absurd example but, I cannot think of any other way to get an objective reading of the light on the GG.

You also must consider that there is likely a print to be made from the negative....so there is another large process beyond camera exposure that plays into the "looks exactly like what I saw on the GG". Generally speaking, for print film, the camera exposure need only be "good enough"...again, simply because, there is a printing process - the negative is only an input to that process...it is not the end result. so if the negative is good enough (notice, perfection is far from necessary here) then a competent worker can make a beautiful print and a master may be able to make a stellar print (even from a poorly exposed negative).

[Mike Green]

Yep - that makes sense. I'd thought about the problem of pupil dilation but with a dark cloth thought I might get away with it.

Guess the bottom line is it's just not worth the ruined negatives to chance it.

Thanks for the response.

[GPS]

Thanks for the reply Brad - sorry I think I was a bit vague but I actually had quite a specific question. I probably shouldn't have written the middle paragraph. I didn't mean to ask generally how should I meter my shots, but specifically - is there an exposure setting which for a given film will always capture the scene exactly as you see it on the ground glass. It seems there probably isn't, but I don't really understand why.

The reason why it cannot work is that we don't have an exposure meter in our head for our eyes to technically estimate the amount of light we see - be it around us or on the ground glass...:) Even the sunny 16 rule speaks about the sun and not the amount of light...

[iozone]

I've found averaging meters sometimes hard to interpret and seldom accurate. two tricks you might try are:

1) Meter your hand and for average caucasion skin add one stop. Be sure your hand fills the frame on your SLR and that your hand is in the same light as the subject, i.e. side light, shade etc.

2) Place a Styrofoam coffee cup over your lens and use your camera as an incident meter. I haven't personally used this but have read that it is very accurate.

I use the hand trick, sometimes even as a check against spot metering.

[r.e.]

Thanks for the reply Brad - sorry I think I was a bit vague but I actually had quite a specific question. I probably shouldn't have written the middle paragraph. I didn't mean to ask generally how should I meter my shots, but specifically - is there an exposure setting which for a given film will always capture the scene exactly as you see it on the ground glass. It seems there probably isn't, but I don't really understand why.

To answer your specific question (if I understand it correctly), I think that if you can train yourself to work without a meter, you can train yourself to make accurate exposure judgements from what you see on your particular ground glass. Indeed, there are attachments for some meters precisely for gauging exposure from the ground glass. Do a Google search for "metering on the ground glass" and you'll find discussion about it. I have an acquaintance who uses one of these probes. It works, quite impressive to watch.

However, it isn't clear to me why someone who can accurately judge exposure without a meter would need to judge it again under the dark cloth - I don't know, maybe it would be useful for fine tuning, but it introduces a number of variables that aren't there when you are just looking at the scene. Could be useful for macro I guess, or maybe for fast changing light.

Myself, I need a meter, at least for general orientation. According to an extremely experienced, rather pithy former participant on this site, now unfortunately deceased, that means that I don't know 'nothin 'bout photography. He once said on here that anyone who knows what he's doing should be able to work without a meter, unless (and I am now paraphrasing) one insists on taking a shot of a black cat peeking out from under a white car under Arizona mid-day sun :)

[aduncanson]

BradS gave a good answer. There are other variables like the amount ambient light and the degree of adaption you allow your eyes under the dark cloth. However your idea is somewhat like an extinction meter which you may want to google.

[pocketfulladoubles]

Just find a used spotmeter at a good price, or at least something like a Gossen LunaPro. They sometimes go for as low as $50, which will be less than the amount of film you waste trying to guess and figure it out.

[Stephen Benskin]

I think Brett Weston used to use the ground glass to determine exposure. He would stop down until a certain value went black. It took years of experience to get to that point though. There were also meters that were called extinction meters that worked in a similar manor.

[Tim Meisburger]

Stopping down to black should work, except, it does not take into account dark adaptation. If you spend some time under a darkcloth your eyes will eventually adapt and allow sight with lower illumination. I think there is not particular advantage to assessing light through the groundglass. I think the sunny 16 rule is probably the best solution to lack of or a broken meter.