Metering with Pentax 645 and a 35mm lens - way oversensitive?

[tales of a flaneur]

<p>I don't have a lot of experience with wide-angle lenses. I suppose I'm a child of the 1970's and love that flap 'Scope look from films like The Parallax View, Midnight Cowboy and Three Days of the Condor. The widest lens I've ever used with any regularity has been a 35mm lens on my Hexar AF.<br>

I've been using a 75mm and a 150mm lens on my Pentax 645 for about a year now. I recently purchased a 35mm lens to better investigate the world through a wide lens and have had some really strange results to date.<br>

I thought the built-in meter on the 645 with 75mm lens was pretty accurate. I would bump the film rating up or down now and again, but it mostly got the exposure right.<br>

With the 35mm lens on, I'm finding it's a lot more sensitive to any strongish light source in the frame. I've only just processed the first rolls, but it looks like it's about two stops. Everything in remotely mixed lighting comes out underexposed. Rating everything a third down (e.g., 320 for Tri-X) helps a lot, but even then it's occasionally not enough.<br>

Can anyone speak about the metering characteristics of the Pentax 645 (or is it really time to buy that spot meter)?<br>

Thanks!</p>

[steve_levine]

<p>Often times the wider glass allows more of the brighter elements into the frame (usually more sky), and can fool your meter. With Tri-X you should be "metering for the shadows" . And "developing for the highlights", as the old saying goes. </p>

[russ_britt3]

<p>Like Steve said, you are metering more sky. Try taking your reading while pointing the lens at a gray road.....or some other thing in the same light as your subject. Even metering your hand would be better than the sky. Unless the sky is your maun subject. Saying that I only use hand held meters.....never meters in the camera.</p>

[stp]

<p>Even if you do meter correctly, the wide angle lens may be taking in a larger range of light than your film can handle. Split ND filters (or combining two different exposures if you are scanning) may be needed.</p>

[tales of a flaneur]

<p>The Pentax 645 is a rather simple beast, and I'm sure I'm just being a bit dim.<br>

After processing a bit more film today, I see that the issue must be the wide-angle and my lack of awareness.<br>

I'm used to manually-metreing older cameras, but in the past I've shot anything with a wide-angle lens on a modern, matrix-metred camera. It seems the centre-weighted 645 is verrry sensitive to pretty much any directional light source in the frame.<br>

Live and learn! Time to remind myself to fiddle with the ISO for exposure compensation - or just break down and get a 645n ;-)<br>

Thanks for the advice, as ever much appreciated!</p>

[ivan_j._eberle1]

<p>My 645N used with the SMC-A 35mm f/3.5 displays one small hiccup in that it sometimes reads f/19.5 or flickers between f/19.5 and f/22 in the viewfinder when set on f/22.<br>

When shooting color neg films, I consider the Pentax Dual 6-Segment meter to be pretty much foolproof. For metering transparency films, though--whenever there's sufficient time-- I prefer to use Spot metering on Manual. This is because the Dual 6- Segment meter tends to be slightly biased toward over-exposure, not under-exposure. It can blow highlights in high dynamic range scenes, as did my Pentax PZ-1 before it. Some of the literature for the PZ-1 described this as the engineering intent of their on-board scene comparison algorithms, for backlit high-EV beach and snow scenes. My Nikon F5 w/3D Matrix Metering , on the other hand, is better dialed-in to almost never blow highlights.</p>