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07-15-2015, 05:37 AM   #1
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Pentax 67 TTL prism + TMax 400

Hi, I just bought this camera.
Already did some rolls and they're waiting for processing.
But maybe some kind of help - I'll skip phase 1 with experimenting under and overexposed films:
-What ISO do You suggest to use for Kodak TMax 400 with Pentax 67 Light Meter?

The real question is that light meters can overexpose, undeexpose - I mean on average.
For example:
1. I've figured out that it is best to add +1/2 stop to Nikon F4 light meter (matrix) when used on Velvia 100, and also it is safe to add full stop when used on negative films (both C41 and B&W)
2. I've figured out something similar in Nikon FM2 (which uses + o - light meter marks in viewfinder)
3. I've figured out that my manual light meter (Sverdlovsk) used with Fuji GSW 690 required 1+ or even +1,5 EV even on B&W negatives....

So my question is what is best exposure compensation for Pentax 67 average light meter when used on B&W negative.
And knowing that exposure compensation I will apply it via changing ISO.
For example from 400 to 250 and have +2/3 EV compensation.

07-15-2015, 06:14 AM   #2
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I think you need to do your own test rolls. Besides the meter you need to consider the variables associated with b & w processing: which developer, how much agitation, how much time for developing? Also someone else's meter is likely to be different than yours.
07-15-2015, 06:39 AM   #3
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Maybe You're right.
I just asked ofr some this like "Pentax 67 TTL meter usually is about +1/2 EV off" - to start with.
I won;t do processing - lab will do that, and usually they do that just "standard" way, always the same for given type of film.

Of course I'll do my test rolls, and let You know results, I've started with +1/3 EV and will see what happens.
07-15-2015, 08:30 AM   #4
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I would highly recommend shooting the first roll as the camera meters so you know how it reacts. I found all my Pentax cameras to a good job metering.

Considering you mentioned using a matrix metering mode, it is possible that the algorithm it uses to balance light between zones may have produced results aimed to not blow out highlights, so your slight over exposure would have bumped shadow detail just a bit and still yielded highlight detail. Think about the old film practice of metering for shadow and developing for highlight. So I can completely see how you may find it giving you results you liked on a regular basis. That said i have not owned Nikon film cameras, and have no personal experience with the meter.

There are different metering modes for different cameras: Averaged, Center weighed, spot, to name a few. For each situation the meter takes and makes the exposure reading exposing for what it considers medium grey (example: exposure with camera pointed at 18% grey card).
Take for instance averaged metering, the whole scene will be averaged for that exposure so depending on the amount of light in certain parts of the image you may not have proper shadow detail, or you may have blown out highlights in the sky. Other meter modes may help you get a better reading on specific scenes. A spot would focus on a very tight point of the scene to meter and expose just for that.

The meter is going to behave predictably and not all lighting situations are equal. You cant apply compensation to a a roll of film and expect it to be the same for each shot. In general exposure compensation should be applied on a per lighting situation basis, not on the meter as a whole. For instance I have always tended towards using more of a spot approach and getting a reading from different parts of the scene, then applying an exposure that will place the shadows where I want them while still retaining the highlights.

Your 67 will average the scene as a whole so you will adjust over or under depending on how dominant the highlight or shadows are and where you want them to be in the tonal range. You may want to look u the basics behind the zone system.


Last edited by johnsey; 07-15-2015 at 08:36 AM.
07-15-2015, 10:31 AM   #5
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I know zone system. I know metering modes available.
I only wanted hint if Pentax 67 have some "tendency".
OK so I assume meter is just OK, and do exactly as You described.
If I want scene to be darker (because it is visally dark) I will adjust, the same with lighter scene.
Thanks a lot for info.

BTW: on Fuji 690 I usually meter shadows, meter highlights and make some average.
But even by doing so I usually ahve to add +1 or 1+1,5.
Maybe meter is just one stop off..... this is quite often for soviet meters....

---------- Post added 07-15-15 at 10:32 AM ----------

I know zone system. I know metering modes available.
I only wanted hint if Pentax 67 have some "tendency".
OK so I assume meter is just OK, and do exactly as You described.
If I want scene to be darker (because it is visally dark) I will adjust, the same with lighter scene.
Thanks a lot for info.

BTW: on Fuji 690 I usually meter shadows, meter highlights and make some average.
But even by doing so I usually ahve to add +1 or 1+1,5.
Maybe meter is just one stop off..... this is quite often for soviet meters....
07-15-2015, 12:39 PM   #6
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QuoteOriginally posted by MorgothV8 Quote
I only wanted hint if Pentax 67 have some "tendency".
These Pentax 6x7 & 67 TTL metered prisms are getting pretty old now and are based on late 1960's technology. Your TTL meter could need recalibrating and be off, so it's hard to recommend a specific setting. Best do your own testing and adjust as required. Take notes for each shot and include the filter factor if you are using one.

Phil.
07-15-2015, 07:57 PM   #7
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The five-stop range of the 6x7/67 TTL meter will handle most scenes reliably, but high contrast scenes will throw it off, so you need to 'tweak' 'the exposure needle in their in small increments and visualise that it is +/- 0.5, 1, 1.5 etc; anything greater requires a separate meter and a more critical take on the scene's contrast range. Ideally a spot meter and judicial 'sweeping' of the scene with that with a bias toward 1 stop underexposure would be preferable to relying on the TTL meter blindly. I think at this time your best option is to run a roll of TMX400 through the 67 and MAR and critically examine the results on a lightbox. Record notes as you go along (don't rely on memory!). Armed with a test set of exposures and a record of metering, you will be much better placed to fine tune results in following rolls. I would not expect bang-perfect results first time based on theory alone. This stuff needs active practice, even if it costs money.

Phil's comment re the age of TTL meters and loss of accuracy over time is true. You can work around this by using a separate spot/incident (both, preferably) meter.
07-22-2015, 04:28 AM   #8
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I have the Pentax 67 TTL-prism for my Pentax 6x7. IŽd suggest testing with colour slide film, not BW-Negative film. This test shows you immediately if the finder is working or not. My TTL prism proved to be very reliable with all kinds of films.

07-23-2015, 12:12 AM   #9
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Hi, Thanks for info.
I know that slides / diapositives have a lot less exposure latitude. Let's say +/- 1/2 stop.
But I want to see first photos developed (negatives B&W) and then if I'm happy with then, change to Velivia 100.
I currently have no slide film, I've used it in both Nikon F4 and Fuji GSW and had no problems with it.
07-25-2015, 09:50 PM - 1 Like   #10
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QuoteOriginally posted by MorgothV8 Quote
Hi, Thanks for info.
I know that slides / diapositives have a lot less exposure latitude. Let's say +/- 1/2 stop.
But I want to see first photos developed (negatives B&W) and then if I'm happy with then, change to Velivia 100.
I currently have no slide film, I've used it in both Nikon F4 and Fuji GSW and had no problems with it.

B&W film is not ideal for testing exposure meters because of its wide latitude. With the Pentax 67 any fundamental error in its TTL metering will be obvious to a trained eye, and especially so to somebody fluent in 'sweeping' a scene with a spot meter with either centre-weighted averaging or mean-weighted averaging, and comparing that to the 67 meter (which is centre-weighted). Correctly used, the TTL meter should correlate well with a multispot+AVGd sweep of key luminance readings.

Transparency film has a bit more latitude than 0.5 stop. Your main problem with high-contrast, saturated transparency films is using them in the conditions which they were designed for, which will influence how well they record the scene e.g. bright point light (midday sun) is definitely not fodder for Velvia 50, 100, 100F or in some cases Provia. You can actually get a 3-stop range recorded on Velvia in diffuse (soft) illumination -- the condition it was specifically designed for. Remember you can get away with shooting with B&W at any ISO speed, but "just any sort" of scene will not always be suitable for high contrast films with saturated palettes (ergo, a need to moderate this) and a predisposition to their problems caused by lighting that is clearly too much for them to handle.

Velvia's typical latitude is 1.5 to 2 stops based on multispot+AVG metering.
09-07-2015, 07:39 AM   #11
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Hi, after developed about 10 films (all of them Tmax 400) negs looks good.
Sent them for 2500 DPI scan about a week ago.
Will see....
09-07-2015, 03:31 PM   #12
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I've only shot one roll with my own recently acquired P6x7. It was Fuji Reala 100 ISO negative and all seemed to come out perfectly - 'll be very happy if that accuracy continues!
09-07-2015, 11:08 PM   #13
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As I said - I'll see scanned results.
But under loupe (4x) looked good, I'm quite happy because ALL shots were hand held - just like shooting Nikon D3.
And some were 1/30s using 105/2.4 ...
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