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01-25-2018, 12:49 PM   #1
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Reciprocity failure? Provia in low light

Hi, Team,

I'm still enjoying my Pentax 67 kit and beginning to experiment more boldly. Over the holidays I visited my folks in Michigan and took some landscapes mostly in black and white. I shot several scenes in the snow around dusk. There was some very beautiful orange in the cloudy sky that I tried to capture with a roll of Provia. I was trying to go for a Michael Kenna-esque long exposure, minimalist, look.

To my dismay, all of the color shots were dramatically underexposed, providing me with unusable negatives, except for one, which was taken in normal light conditions. I can therefore rule out processing failure. All of the black and white negatives turned out beautifully (except for the roll that the camera store destroyed!).

I'm wondering why the color negs turned out so dark, even though my exposure calculations appear accurate based on my Fuji Acros 100 (black and white) negatives. I metered using a Zone 6 Modified light meter.

I was shooting 15 second exposures at about f/16 or f/22. Did I dramatically underestimate my exposure values? Was I the victim of reciprocity failure? Should I never try to use color slide film in very low light conditions? Is my light meter inappropriate for metering color images?

Also of note, several of my daylight shots using Provia seem dim. Should I crank up the exposure for this film a stop based on what my Zone 6 is telling me?

Thanks in advance!

01-25-2018, 01:14 PM   #2
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It's been a long time since I shot color slides, but those exposure values don't sound like where reciprocity failure would be implicated. I looked up some Fujichrome data sheets and 100x and 400x provia neither one are prone to early reciprocity failure per the sheets. The 100x said exposures in excess of 128 seconds and the 400x said in excess of 2 mins. Neither of which was involved here.

I'm stumped. But I'm no expert on film these days. I wish I could help more.
01-25-2018, 01:17 PM - 1 Like   #3
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Provia is one of the better films as far as reciprocity failure, and you shouldn't get much failure at 15 seconds.
I would guess that your metering wasn't correct. Metering at that time of day is tricky at best, and the snow makes it more difficult. Add to that, after the sun sets, you are losing light fairly quickly, so between metering and shooting you could lose a stop or more, if you're not quick.
01-25-2018, 01:34 PM - 1 Like   #4
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Acros is a negative film while Provia is a slide film. The exposure latitude on neg film is much greater than with slide film. You could have easily been off on your exposure on both types of film but the B&W being more forgiving, didn't show up as being off. The exposure latitude with Provia is not forgiving and will show mistakes. Also, using a handheld meter in a quickly changing scene can be a problem if the light is fading. Sometimes using the TTL meter off the clouds and bracketing works better. Just my guess as to what happened with your Provia.

01-25-2018, 02:17 PM   #5
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I would not expect recriprocity to be a critical factor at 15 seconds with Provia. Exposures that I have made with RDPIII have gone to 30 seconds with no casting or absolute reciprocity.

But I think there is an error in your metering methodology, or the meter itself -- has this been checked?
I use a Sekonic L758D and rarely get a 'slap in the face', aka under- or overexposed slide from Velvia (a lot more critical than Provia!), and when it is noticed, it can be traced to a mismatch in settings between the meter and the camera, an incorrect filter factor, a wrong ISO... any number of human faults.

Slide film can be used in low light if you are astute with metering and can keep out of the red zone of exposure that the film does not work well at, but not near darkness as the increased exposure time will definitely lead to reciprocity errors and casting. A faster emulsion like Provia 400X (a bit rare now, but still available) is a better choice, or switch to negative film like Portra 400 and push it to EI800.
01-25-2018, 04:02 PM   #6
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Probably not reciprocity. I would shoot two shots of a test scene (with fixed lighting conditions), each with the exact same exposure (maybe both short and long shutter speeds), and see how they compare. The slide film will have more contrast but it should tolerate under exposure better than a negative film. I would guess that the originals exposures were in error somehow but only tests can confirm that. Use your Zone 6 exposure meter and you can check it at the same time.

It could also have been development of the two films. The B&W is much less susceptible to processing variations than the Provia and if you had it developed where your one roll was destroyed, that could be the answer. Probably not the case though since that one shot came out properly.
01-25-2018, 04:30 PM   #7
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Although it may not be reciprocity failure I always increased exposure from the metered reading for both Velvia and Provia whenever I was beyond 1 to 2 seconds. I also would bracket liberally (at least a full stop) -- for a metered reading of 15 seconds I'd probably have shot the scene at 15, 22-23, 30 and 40 seconds if I was on roll film. On sheet film I'd keep good records, develop 1 sheet and the adjust the processing of my second or third sheet accordingly. Even though film and processing has gotten real expensive the extra exposures are cheaper than reshooting and hoping for the same conditions.


Also, if it helps, I routinely shot Provia at 200 in low light situations and had the lab adjust processing +1 with no ill effect. You can also do this to a lesser extent with Velvia but the shadows would block up more quickly when it was pushed so if you have a shot with a lot of shadow detail it wasn't worth it.

01-25-2018, 08:02 PM   #8
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As said before it was one of a couple things or a combination of:
1. Bad light meter
2. Fading light
3. Did not use meter correctly.

When metering remember the meter reads an 18% gray that is medium gray. If you are metering white or black you need to compensate 1 or 2 stops since the meter wants to expose that and make it gray. Overexpose white 1-2 stops and under expose black 1-2 stops. I am guessing you did not compensate for the snow. You should have adjusted and exposed 2 more stops stops if things are that far off.

When metering, meter the shadows if in doubt and see how that works. In very high contrast you may have to expose in the middle some place and depending on what you are trying to do. Set the exposure closer to the shadow detail than highlights. Keep at it you will learn. We all have been and are still there. There is always something new to learn.
01-26-2018, 08:29 AM   #9
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Thank you for the tremendous responses, everyone!

I think its possible that a number of things occurred, based off of your feedback:

1) The conditions quickly darkened and I didn't appropriately re-meter
2) I didn't accurately meter for 18% grey, and since I've mostly been shooting black and white, I've gotten away with poor exposure calculations thus far
3) The meter is wonky

Questions:

1) How do I test my meter and fix it if need be?
2) Computing the appropriate exposure in darkness clearly challenged me. Do you know of any resources that provide advanced instructions for metering in challenging conditions?
3) When you bracket, do you under or over expose, or both? This time I shot twice. Once at the exposure I thought was right, and once a stop underexposed. I've found there's not a tremendous difference in the scans, except the underexposed shot is naturally more contrasty.

The good news is that I'm not particularly interested in low light color slide photography. I'm sold on Black and White landscapes. But it would be nice to learn how to use slide better. I may be taking my kit to Arizona in May and will certainly want to be shooting lots of color.

---------- Post added 01-26-18 at 09:41 AM ----------



---------- Post added 01-26-18 at 09:44 AM ----------



---------- Post added 01-26-18 at 09:50 AM ----------

This is what the negative scan looked like before I restored it. Creve Coeur Camera really mucked it up.


Last edited by Femto1969; 01-26-2018 at 08:39 AM.
01-26-2018, 09:46 AM   #10
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I was not a black and white shooter so I think others will offer better advice there but for the color slide films your bracketing in low light should have been in the opposite direction -- instead of underexposing you needed to add exposure -- as mentioned above if your metered reading was 15 seconds an extra stop of exposure would be 30 seconds. I'd probably add another bracket at about 40 seconds. I used to meter my scenes off a grey card -- they are very cheap and you can buy an 8x10 grey card and cut it into 4 pieces so that you'll always have one in whatever bag your carrying (and to replace them as they get older and dirty). One easy method that I used (I think I picked it up from one of John Fielder's books) is to take a spot meter reading from your scene at a 45 degree angle left and 45 degree angle right when facing your scene and average them in your head quickly to get your base exposure (easier to do than it sounds once you practice it) -- you can bracket around this and if under regular conditions you do a -1 and + 1 bracket you should be fine. As you get better decrease your bracket to +1/2 and -1/2. In low and decreasing light bracket more to the plus (adding exposure) side. Always remember the old adage -- it's cheaper to bracket than it is to reshoot. Take good notes and review the film to see if patterns develop when shooting in different light conditions and adjust your exposures accordingly.


If you find your exposures to long almost all black and white films and some slide films can be pushed a stop and adjusted in processing. I routinely shot Provia at 200 (more for wind reasons than light) and often shot it at 400 and had the lab adjust its processing.


To test your light meter take a spot reading off a grey card and then use the spot metering mode from your (or a borrowed) camera and see whether they match.


Hope this helps .... and have fun!


Actually just to clarify -- the spot meter readings you are taking at the 45 degree angles are off the grey card that you are holding in front of you in the same light that is falling on the scene you are metering.

Last edited by travelswsage; 01-26-2018 at 09:57 AM. Reason: adding clarification
01-26-2018, 01:45 PM   #11
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Good God!
Those pics look like opening stills to a Hitchcock movie! I actually like the moody, gritty, film-noir look. The pic which has been botched by the lab is something that would make me ropeable. Anyways, got to get out of here now, Australia Day is outta the way and the weekend is now here! Cheers.
01-26-2018, 02:12 PM   #12
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QuoteOriginally posted by travelswsage Quote
I was not a black and white shooter so I think others will offer better advice there but for the color slide films your bracketing in low light should have been in the opposite direction -- instead of underexposing you needed to add exposure -- as mentioned above if your metered reading was 15 seconds an extra stop of exposure would be 30 seconds. I'd probably add another bracket at about 40 seconds. I used to meter my scenes off a grey card -- they are very cheap and you can buy an 8x10 grey card and cut it into 4 pieces so that you'll always have one in whatever bag your carrying (and to replace them as they get older and dirty). One easy method that I used (I think I picked it up from one of John Fielder's books) is to take a spot meter reading from your scene at a 45 degree angle left and 45 degree angle right when facing your scene and average them in your head quickly to get your base exposure (easier to do than it sounds once you practice it) -- you can bracket around this and if under regular conditions you do a -1 and + 1 bracket you should be fine. As you get better decrease your bracket to +1/2 and -1/2. In low and decreasing light bracket more to the plus (adding exposure) side. Always remember the old adage -- it's cheaper to bracket than it is to reshoot. Take good notes and review the film to see if patterns develop when shooting in different light conditions and adjust your exposures accordingly.


If you find your exposures to long almost all black and white films and some slide films can be pushed a stop and adjusted in processing. I routinely shot Provia at 200 (more for wind reasons than light) and often shot it at 400 and had the lab adjust its processing.


To test your light meter take a spot reading off a grey card and then use the spot metering mode from your (or a borrowed) camera and see whether they match.


Hope this helps .... and have fun!


Actually just to clarify -- the spot meter readings you are taking at the 45 degree angles are off the grey card that you are holding in front of you in the same light that is falling on the scene you are metering.
This is great advice. I just ordered my grey card. I need to get over the pain of spending $3-4 per scene via bracketing. I do wish I would have been more careful with the color slide film because I won't be back to that particular scene in at least a year.

I've not yet started experimenting with pushing and pulling. I'm still trying to hammer out the basics of shooting with film at proper exposures. But when I do, I will take your advice. There's a lot to learn and no one I shoot with who has a better grasp on it than I do. So I'm teaching myself pretty much everything. Thank you to everyone here for helping me learn the ropes!

Street, I'm really glad you like those images! Yes, I am going for Hitchcock/Stephen King with a splash of Michael Kenna minimalism. I'm nowhere close to where I want to be. There seems to be an ocean between the images I'm producing now and what I hope to be able to print (and sell).

I forgot to add these photos to the collection. Please bear in mind that these are all rips from Facebook so the resolution is murdered compared to the original scan.

---------- Post added 01-26-18 at 03:13 PM ----------

01-26-2018, 02:21 PM - 1 Like   #13
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I've shot a lot of Fuji Provia 100F (135) and 400X (135 & 120) over the last few years, since Kodak dropped all E6 film and neither of the Fuji films like the morning or evening light. The colour temp is a bit different and can be corrected with a Pentax 6x7 Morning & Evening filter.

This, the snow and metering errors all contributed to the under exposed shots.

Phil.
01-26-2018, 02:35 PM   #14
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FYI, If you are going to use a gray card, remember that they work especially well with the TTL meter. Typically, the TTL can be faked out by very dark or very light areas in the scene but with the gray card, those errors are lessened greatly. These cards are not as simple to use as you might first expect, so heeding the above advice is warranted.
01-26-2018, 07:21 PM   #15
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Actually those are some cool shots. Might not be what you wanted but they are cool.

So in this situation spot meter off a tree trunk or off the side of the little shed or off the side of the bridge. try that exposure with that reading or

Take another spot meter on the snow and calculte what 1 AND 2 f stop adjustment would be and compare it to your spot metering on the tree/shed/bridge. If they are close go with one, or split the difference.

Lets say the bridge. You are shooting at f8 and it says use 1/30 but the snow reading says use 1/500. so 1/500-2f stops is 1/125th. You could go with 1/60th and split the differance or bracket and shoot 1/125, 1/60 and 1/30. That gets expensive however.

When you shoot track what your settings ere for each shot then see how they turn out. If you see a trend ie everything under exposed then look at your light meter.
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