Light meter question

Stelex

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I'm new here and new to film photography, or rather returning after decades.

I bought some old Canon cameras (F1n and 2 x A1). Metering on them gets me confused.

I meter something with one of A1s and it feels it has a bit of overexposure, then I meter with the other one and I get the same result. Good.

But then I meter the same thing with F-1n and with the same lens and I get about 2/3 - 1 1/3 stops different reading.

I've got the first roll of film developed that I've shot on F-1 and it looks about 1 stop underexposed on most, if not all photos, so that would explain the difference above.

Then I take to compare these three cameras with A7II and 5DmkIII and lo and behold, they both agree with F-1.

What the heck!

Here are some example values of me metering a white curtain in my apartment well after midnight and not too much light. In all cases the curtain fills entire viewfinder on cameras. All cameras are set to ISO 400, all in M mode, s/s at 1/4 sec. Curtain is evenly lit

A1( #1) 50mm - f/4.5
A1 (#2) 50mm - f/4.5
F1 @50mm - f/5.6
A7 @40mm - f/6.3
5Dmk3 @35mm - f/5.6

Do I assume that metering should be the same on digital and film cameras at the same ISO or are there any other tricks that I need to take into consideration.

I'm half way through my first roll on A1, so it will be a short while before I see results.
 

BrianShaw

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I don't know Canon very well but I suspect that if you check the manual or spec sheets you'll find that they have different metering patterns or algorithms.
 

Chan Tran

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If you shoot color negative then 2/3 stop over is good. If you shoot digital some underexposure is fine.
 

Alan9940

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And, this is why I use a handheld spot meter; more accurate and I'm in control.
 

Leigh B

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Getting matching spot readings is EXTREMELY difficult, requiring much practice, careful evaluation of the subject, matching calibration of the instruments, and very precise working habits.

I strongly suggest using incident readings and believe what the meter tells you, unless you're shooting very unusual subjects.

- Leigh
 

naeroscatu

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+1 on the above comment. Make sure all cameras are set for the same exposure mode (spot/ center weight/ matrix) so you compare apples with apples.
 

Leigh B

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naeroscatu said:
Make sure all cameras are set for the same exposure mode (spot/ center weight/ matrix) so you compare apples with apples.
Click to expand...
But shutter speeds can vary by as much as 30% + or - and still be "in spec".

So you can end up with fat apples and skinny apples.

- Leigh
 
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Stelex

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naeroscatu said:
+1 on the above comment. Make sure all cameras are set for the same exposure mode (spot/ center weight/ matrix) so you compare apples with apples.
Click to expand...

Digital ones are on centre weighted metering, the film are what they are (centre, I believe). Even if there is a difference I have made sure the curtain fills the frame so with uniform lighting there shouldn't be any difference.

I'll try some sunny f16 today to see how that looks. Other than that, and since I don't have an external light meter, I guess there is little I can do except to wait and see the results of the current film roll. If this roll turns out ok,I think the F-1 will need to be set up to +2/3 or +1 f-stop.

How accurate are the mobile apps (Android) for ambient metering?
 

MattKing

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Show us a picture of the negatives.
The scans really only tell us about how your scanner and scanning software interpreted the negatives.
Over and under exposure is evaluated by examining the shadows and highlights on the negatives (mainly the shadows).
 

Mainecoonmaniac

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I think each camera "weights" it's exposure differently. This means that the sensitivity of the of area in focusing screen varies. Some camera manufacturers use different matrixes as their secret sauce in getting the "Perfect" exposure. My canon F-1 (n) has different focusing screens available. But I'm used to my center weighted focusing screen. When I shoot manually in a back lit scene, I open up a stop because I know the meter is getting fooled.

https://severnschoolkapsos.wordpress.com/digital-media/metering-with-a-digital-camera/
 

markbarendt

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The positives don't really count, as silly as that may sound.

With negatives, inside a fairly large range of camera exposures, there is no implicit connection between the positive and the negative.

To judge minimum negative exposure you need to print from the 'thinnest' parts of the negative and see what you get. (Not to print for good prints)
 

wiltw

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Because each of the cameras have different metering patterns or weighting of different areas within the viewfinder, what you can do to somewhat 'equalize' comparisons is to put yourself in front of a somewhat uniformly illuminated, uniformly colored wall. Aim each of the cameras at the same spot on the wall (you might simple put a small dot of tape on the wall so that you center it in each of the frames) and compare the readings from each of the cameras...yet due to differences in factory calibration the meters may not match perfectly even when new from the factory! But they should all be within about 0.5EV of each other.

I just measured a recently calibrated Olympus OM-1 and used a Minolta Spotmeter F which matches my Canon (5D and 40D) cameras.
  • OM-1: ISO1600 1/250 f/2.8
  • Minolta Spotmeter F: ISO1600 1/400 f/2.8
  • Canon 40D: ISO1600 1/400 f/2.8
  • Canon 5D: ISO1600 1/400 f/2.8
  • Canon 7DII: ISO1600 1/320 f/2.8
BTW, the 7DII exposes so that histogram peaks exactly at the middle of the histogram, whereas the peaks on the 40D and 5D are about 0.33EV-0.5EV below midpoint...so I think my 7DII exposes more as I would expect the reflected light meter to behave...putting the metered surface at the midpoint. So the OM-1 meter is within 0.33EV of the digital camera meter which I trust the most for 'as expected' results. And if I compensate the 40D and 5D meters to peak at mid-histogram, their meters match the 7DII.

I now see that you have essentially done that via pointing all a white curtain in your apartment. Based upon those readings,
  • sample 1 matches sample 2, sample 3 matches sample 5, the A7 readings seem to be the outlier...
  • but OTOH, sample 3 matches sample 5, and sample 4 is within 0.5EV of 3 & 5, so the pair of A1 readings might be the outliers
I'd like to see a scan of the film as negatives (try to scan them as 'color transparencies', before jumping to a conclusion, though. Just viewing the dropbox photos, none appear to be the result of a badly exposed neg, and none appear 'overexposed' to my eye...but the truth is the negative density.
 
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Mainecoonmaniac

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I don't think there's really a "Correct" exposure. It's mostly what a photographer wants to record in a scene.
 

wiltw

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Mainecoonmaniac said:
I don't think there's really a "Correct" exposure. It's mostly what a photographer wants to record in a scene.
Click to expand...

A lot of truth to that statement. Lookit the results I have with three digital camera meters, and the resulting exposures as reported in post 14!

And given the variability of shutter speeds, and the variability of f/stops (true vs. stated) affecting the actual exposure, what one really needs to understand is the delivered performance of the camera vs. the meter suggestion, so that your results are 'as expected'.
 
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Mainecoonmaniac

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What I meant is that it's a creative call. I'm not going to get dogmatic about how to compose and expose, but photographers should know the range of film. Our eyes has so much more dynamic range. We see shadow and highlight detail at a bright scene that film doesn't see. The creative part is deciding whether shadow detail is important. Is highlight detail important? That's the whole point of the Zone System. But that's also a trap in itself. There are some photographers are expert technicians in exposing and getting detail out of a scene, but the images are boring.
 

Alan W

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Not wanting to be a wise guy or anything,but your life will change dramatically if you can get yourself a working T90.If you like fd lenses,as I do,you will learn to love it's multi spot meter.It can take,and average out,several readings at a time.Its a remarkable camera.Other than that,I also have and use several F1's and just live with the occasional under/over exposure and compensate as best as I can in the darkroom.When taking "grab" shots you sometimes have to accept imperfections.
 

Mr Bill

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Mainecoonmaniac said:
I don't think there's really a "Correct" exposure. It's mostly what a photographer wants to record in a scene.
Click to expand...

There actually is, in a way, a "correct" exposure for most pro portrait color neg films in a typical studio environment. These "correct" exposures are somewhat defined by the manufacturer in the aim densities for fleshtones and grey card. Additionally, they all used to (I don't know if this is done anymore) supply printer setup negs, aka slope neg, that photofinishers would use. These were supplied with a "normal" exposure, plus both under and over-exposed negatives.

I don't know exactly how they determined the "normal" exposure, but in my experience with such kodak films is that, in a conventional front-lit electronic flash portrait, a pro-grade (Minolta) flashmeter with an incident (dome) reading, the meter would put you right on the money.

Once you go away from these specific conditions, then who can say?
 

Mainecoonmaniac

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Yes that is true in this case. Some portrait studios are highly controlled environments where the aim is a consistent and visually pleasing product. Also, this saves major guess work from the color printing end. I'd imagine Lifetouch has such parameters during the film days. It's much like a fast food restaurant where the cooks don't have much leeway in how the food is cooked. In this case, a consistent, palatable product.
 

Mr Bill

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Mainecoonmaniac said:
I'd imagine Lifetouch has such parameters during the film days. It's much like a fast food restaurant where the cooks don't have much leeway in how the food is cooked. In this case, a consistent, palatable product.
Click to expand...

In school pictures, which was their main business, I'd mostly concur with you.

But although I specifically named portrait studios, this spec for "normal" exposure really pertains to just about any people pictures, under "daylight" conditions, and not backlit, that are shot on a pro portrait color neg and processed in a pro lab. Sorry about all the disclaimers, but I don't want to mislead.

Anyone who shot weddings on such films prior to the digital revolution could have asked their pro lab, "How are my exposures?" If it was a decent sized lab, they could tell you, "oh, you're about a half or two-thirds stop over on the such and such shots," or that sort of thing. But if one never spoke to their lab, or it wasn't a pro lab, they likely wouldn't know about this sort of thing. And in truth, it didn't much matter to these photographers, as these films had so much exposure latitude, mainly on the over side, that it didn't make much difference.
 

Mainecoonmaniac

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I worked at Caltrans during my younger days and I worked for a photographer that did hundreds of head shots. I'd have to print them. The lighting was flat. If the C-41 machine and the RA machine's chemistry was right on, I could print them without redoing the filter pack. Assuming the film and paper was from the same batch But it was mind numbing work.
 

Mr Bill

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Mainecoonmaniac said:
But it was mind numbing work.
Click to expand...

I know that I'm running off topic, but I used to tell people that our operation was essentially a picture factory, and the people doing color-correcting, dust spotting, and running printers and processing machines were, in essence, production-line factory workers. As a note, I occasionally would ask some of the printers, didn't that repetitious work drive them nuts? And almost always, it was no, I can do this without thinking, so while I work I'm planning dinner tonight, and various other family things. So I guess that work is what you make of it, or what it means to you.

As a note, given that you refer to "hundreds of head shots," and "redoing the filter pack" (the good old days), I'm guessing you may have never seen "printer setup negs." With manual filter packs, their only use would have been with a video analyzer like Kodak's VCNA. And since VCNAs used to cost as much as a small house, I'm guessing you didn't have one. I may be "dissing" smaller pro labs, but back in the day a VCNA was the big productivity tool, eliminating one or two color balance tests. It became a completely different world when a main mini-computer took over control of printer exposure and color balance, according to the analyzer data for each neg. I guess I'm reminiscing too much.
 
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Stelex

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Thanks everyone for your helpful advice. It's so much harder to get things right when you're shooting 'blind' after years of digital photography. But hat is the challenge and a thrill that I want and something I want to learn to 'feel'. I just want to make sure the equipment is up to scratch. It would be so much easier if someone was still making new film SLRs so one doesn't have to worry about the age of the equipment.

I don't have the film to look at density (?), it's still at the lab, I just dropped it off and asked for scans, I'll pick up the film next time I go there.

You guys are right, it's the creative expression of the photographer and what's over or under exposed for one might be the perfect shot for another. For my liking they're somewhat overexposed. As a comparison the adjusted image below would be my preference.

I've loaded another film (ISO 100) in the camera now and set the ISO to 160 so to underexpose it about 2/3, but will process it as normal. Hopefully it will bring the final photos where I want them to be. This one is colour, though - Fuji Reala 100, expired in 1999, kept frozen ever since.

Original image




After adjustment.
 
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