How Effective is the TTL Prism for the Pentax 67?

[thomas_hofmann]

I've just purchased a Pentax 67 body and a couple of lenses.

However, I now need to buy a prism for the body.

 

I would like to know how effective is the TTL Prism for the 67. Most

of my experience in photography over the last 15 years has been with

Nikon's matrix metering system. I understand that the TTL Prism is

an averaged metering system (as opposed to center-weighted average

common to 35mm cameras). Is this going to be huge change for me?

Will the Pentax's averaging system give me reliable and consistant

results? Or would I be better off, as some have suggested, dragging

a 35mm body around with me to meter the scene. Obviously, I

understand the Pentax meter will require more thought and

compensation than Nikon's matrix meters, but with practice does TTL

prism give good results for shooting slides?

 

Thanks

[douglas_green1]

I'd say that it's more of a center-weighted averaging system than a true averaging meter. It's very accurate. Plenty good enough for chromes. I personally found that I don't need to make any mental adjustment going from my Manual focus older Nikons, (like the FE and FG) with center-weighted meters, to the Pentax 67.

 

I also use a Luna Pro SBC, and the readings are the same with the Pentax TTL prism and the Luna Pro, when the same portion of the photo is being metered.

 

But the most important piece of advice is, as always, BRACKET your exposures. It's the same advice I'd give for use with any 35mm system.

 

Dragging a 35mm camera around to meter is the SILLIEST thing I've ever heard. Get a hand held spot meter.

 

BTW, I should preface this reply with my personal bias: That is that Matrix metering is not something I EVER use. Because with a Matrix system, I don't know what the darn camera is metering. I VASTLY prefer center-weighted averaging metering to Matrix, because there's NOT any computer chip making decisions for me. In very short order, with a center-weighted averaging system, I know what type of lighting will fool the meter, and I have a pretty good idea by how much, so I adjust for it. With a Matrix system, I have no idea how much I'll need to correct for what the meter circuit is doing, hence I can't determine how to adjust for it.

[stemked]

Hi Thomas.

 

I have the TTL meter and have generally found mine very accurate. I'd say 90% of my images I take straight with the TTL. However there are obviously times when it is less than ideal because it is averaged lighting. Here are my ways to try and photograph tricky situations.

 

1) First reposition the image so I'm metering more or less the lighting I want and read through the TTL.

 

2) Put on a longer lens and try and point at something in the image that will give me a neutral reading.

 

3) Use the 67 to K mount adaptor and take a centerweighted reading using the same lens with one of my newer (post K series) Pentax cameras.

 

4) When all eles fails use a spotmeter.

[george_rhodes]

I agree with Douglas, that the TTL meter for the 67 is more of a center-weighted averaging meter and it is very accurate, at least for what I shoot, which is landscapes. You won't need to carry around the 35mm camera, because it won't be any more accurate. If you need a spot meter, I'd recommend a hand held meter. However, if your 35mm camera has a spot meter and you need the spot meter, then I guess carrying the 35mm with you would make sense, as you would not have to invest in a nice hand held spot meter. When shooting landscapes, my Pentax meter reads the same as the super-accurate honeycomb meter in my Maxxum 9, when the 9 is set on either honeycomb or center-weighted averaging. However, I strongly recommend bracketing your exposures a bit, just to be sure of getting the very best exposure. I'd do that with any type of meter, no matter how accurate it is. Sometimes a slightly overexposed or underexposed transparency looks best. I highly recommend the TTL meter for the Pentax 67. I think you'll like it.

[frank_miles1]

I bought a Pentax 67II a couple of years back, while I was working overseas. While shooting my second roll of film, I realized the readings from the TTL prism did not agree with the "Sunny 16" rule while those from my trusty Nikon F3 did. I went right back to the store in Abu Dhabi where I bought it, and we tried different combinations of my camera and TTL prism with others in store. The readings from the various combinations were consistently one stop under, compared to readings from the Nikon FM I took with me.

 

In the end, I had to conclude that the 67II's being sold there came with a brighter focusing screen, an option I believe was listed in the manual. (The camera also displayed intermediate shutter speeds, which was also listed as an option.) So, I leave the exposure compensation to +1 and everything is fine when I shoot slides.

 

I would recommend you check your 67II against your Nikon once to verify you are getting basically the same reading and then put your trust in the 67II prism metering. If you want centre weighting, you can set the meter to check against a centre area, or you can use the spot meter.

[george_rhodes]

There is some confusion here. The TTL prism is a match needle, manual meter, which was designed for the Pentax 67 - not for the newer Pentax 67II, which uses the newer, matched AE finder, which offers aperture priority automatic metering.

[george_rhodes]

From his posting, I conclude that Thomas is shooting with a Pentax 67 - not with the newer Pentax 67II.

[cosmo_genovese]

I've always found my TTL Prism meter to be dead-on.

[steve_rasmussen]

For difficult metering situations with the TTL, try using a gray card. Any center weighted meter can be faked out by differential lighting. The gray card isn't perfect, due to different readings when the angle of the card is changed, but it works pretty well.

[richard van hoesel]

One situation in which you will not be able to meter with the TTL is in very low light. Even opened up all the way, the 4 second limit (with your shutter-speed dial on X) sometimes doesn't get me there with slow film I tend to use, but then again I often can't see the needle by then and have to guess anyway :) In general though, I think you can get to know these meters in a reasonable amount of time.

[richard van hoesel]

I forgot to add that you might need to have your TTL meter calibraterd to get its simple sensor bahaving more or less linearly - if I remember right there are about 3 or 4 trim-pots in it that cover the available metering range. I found that when I first got my (used) prism, the difference for metering stopped down was at least a stop out compared to what you would expect from the wide open meter readings.