WestMichigan Posted June 20, 2012 Share #1 Posted June 20, 2012 Advertisement (gone after registration) Hello, I am wondering if M8's in general have poor metering accuracy with longer lenses or is it specific to my Camera or my methodology? The camera usually meters quite predictably when I'm shooting with my 28, 40, and 75, and I easily adjust appropriately for what a center weighted meter trips over -or- for what what histograms are telling me. However when using my 90 elmarit and especially my newly received Hektor 135 the meter is usually over exposing or under exposing +/- .5 to 2 full stops. Worse, it's doing so without a predictable pattern I can pick up on except to note that it is most innacurate the higher the contrast in the scene is. I am getting peeved with this because I learned to use & interpret center-weighted meters a quarter century ago with an SRT-102, then a parade of Minolta X's, and had been doing just fine these days with my M8. I have half talked myself into buying a Spotmeter. Can anyone offer suggestions? Sincerely Richard in Michigan Link to post Share on other sites More sharing options...
Advertisement Posted June 20, 2012 Posted June 20, 2012 Hi WestMichigan, Take a look here M8 Metering Badly w/ 90 & 135 lenses. I'm sure you'll find what you were looking for!
Michael Geschlecht Posted June 20, 2012 Share #2 Posted June 20, 2012 Hello Richard, This may be a silly question but: Unlike the SLR's you mentioned which always meter the same pattern on the same screen: Are you remembering to mentally reconfigure the metering pattern in the viewfinder to each different focal length lens? Best Regards, Michael Link to post Share on other sites More sharing options...
brianv Posted June 20, 2012 Share #3 Posted June 20, 2012 I routinely use long focal length lenses on the M8 and M9 and it meters with them correctly. Metering problems that I have seen were caused by 1) reflections in the lens barrel, eliminated by using a Black permanent marker. This happened when adapting a Leica Varob 5cm F3.5 to M-Mount. http://www.mu-43.com/gallery/g1612-leitz-varob-5cm-f3-5-2c-converted-to-rf-coupled-leica-mount.html 2) Flare, and light haze in the lens can make it worse. Use a deep lens hood. Hope this helps. I have a Hektor-M 135/4.5. I used it recently on the M9- was fine. I use a 9cm F4 Elmar, Nikkor 8.5cm F2, Nikkor 10.5cm F2.5, and Summicron-M 90/2 on the M8 with good results. Link to post Share on other sites More sharing options...
WestMichigan Posted June 20, 2012 Author Share #4 Posted June 20, 2012 Hello Richard, This may be a silly question but: Unlike the SLR's you mentioned which always meter the same pattern on the same screen: Are you remembering to mentally reconfigure the metering pattern in the viewfinder to each different focal length lens? Best Regards, Michael Hi Michael, I see your point and while I would say I probably havent gotten the metering pattern transfered to what the viewfinder is telling me yet, that doesnt seem to explain why my manual exposures dialed in using the histogram to control the highlights are untransferable to a different composition. To my mind, when the sun didnt move, my shooting position didnt move, and there are no clouds, the sunlit highlights ought to stay within a reasonable range using the same exposure? Shouldnt it? RW Link to post Share on other sites More sharing options...
WestMichigan Posted June 20, 2012 Author Share #5 Posted June 20, 2012 I might have just answered my question writing the post above. Even when I used my histogram to dial in my exposure on manual, that exposure wouldnt be transferable to a different section of the same evenly lit view. There were no clouds, no fast changing sunset light (mid afternoon actually), and limited shade in scene I'm thinking of. I believe the cause is the lens itself and the wayit handles light. I did have a deep lens hood on the Hektor in the above scene and the sun to my back, but NO uv/ir filter attached. RW Link to post Share on other sites More sharing options...
tobey bilek Posted June 22, 2012 Share #6 Posted June 22, 2012 All things being equal, the proper exposure for a 28 should be same for a 135. I have yet to find a reliable in camera meter, or any reflected type for that matter unless I carry a grey patch. I use the spot meter in my Nikons, or a Pentax Digital Spot, or an incident type. Link to post Share on other sites More sharing options...
Michael Geschlecht Posted June 23, 2012 Share #7 Posted June 23, 2012 Advertisement (gone after registration) Hello RW, Your highlights will not necessarily stay the same if your angle to the light source changes. Even if it is from the same point. Try re-metering a scene after you change your angle of view. This is a time historically when for some reason many people want to skip metering & do not see precise exposure determination as a critical part of picture taking. Guessing exposure is exactly the same as guessing which shutter speed the camera is set @ or guessing where the aperture dial might be w/o looking @ it. It is different than knowing how to detrmine exposure in certain circumstances w/o a meter & not needing 1. Some people can & do determine exposure quite competently w/o a meter in certain circumstances. Some other people, alternatively, like to use a meter to remove as many variables as they can to increase the likelyhood of producing a better picture. It is a matter of circumstance, personal choice & ability. In many situations there is time to meter appropriately. In some: Whether to meter or guess because of circumstance is simply a roll of the Cosmic Dice. Altho some people see metering w/ a meter as a somewhat labyrithine complexity. Proper metering is actually not that time consuming or difficult. About the same as setting a shutter speed, setting an aperture or focussing. Best Regards, Michael Who likes to meter when he is able to but has been known @ times to guess. Link to post Share on other sites More sharing options...
wda Posted June 23, 2012 Share #8 Posted June 23, 2012 Richard, I have no problems metering when using a 135mm Elmar or 90mm Elmarit lens on my M8. It is easy to forget that metering is a skill, sometimes overlooked in haste. For peace of mind, borrow or buy a separate meter for establishing general exposures. Many prefer a hand meter. But for convenience most rely on that built into the M8. With longer lenses you are narrowing the angle of metering, so a general measurement might need fine tuning, which is easy to do having checked the histogram. Link to post Share on other sites More sharing options...
lars_bergquist Posted June 23, 2012 Share #9 Posted June 23, 2012 Do this experiment: Find an evenly lit surface of even hue and reflectance – a Gray Card or its equivalent – large enough to completely fill the finder at any convenient distance. Meter and expose with your 'standard lens' whatever it is, at infinity. Repeat with the offending lenses, still at infinity, and at the same distance. If all three exposures are equal, the problem is your technique. This is just like statistics: The larger the sample is, the more representative of the whole it is. A wide angle lens takes a large sample of reality (which is presumed to have a reflectance of 18% in most cases). So chances are good that the sample too will approach 18%.Longer lenses make progressively smaller samples, which show more random variation from the global value. The safest course with long lenses is to meter manually, aiming at a part of the subject that has a reflectance approaching 18% or a medium grey tone, or Zone V for followers of that religion. Or, strangely enough, to meter incident light, if the light falling on your back is the same as that on the subject. The old man from the Selenium Age Link to post Share on other sites More sharing options...
WestMichigan Posted June 23, 2012 Author Share #10 Posted June 23, 2012 Thank You Lars, excellent suggestions. I am going to give them a whirl this weekend. I have gotten some of the vAriability smoothed out: I have been shooting with a Nikkor 13.5cm last couple of days rather than my Hektor 135 and my in camera metering isnt nearly as erratically over exposed, BUT does consistently over expose about 2/3rds of a stop. I will also be digging my Hand Held Meter out of storage (it's in my view camera case) to see what that's telling me. Sincerely Richard in Michigan Do this experiment: Find an evenly lit surface of even hue and reflectance – a Gray Card or its equivalent – large enough to completely fill the finder at any convenient distance. Meter and expose with your 'standard lens' whatever it is, at infinity. Repeat with the offending lenses, still at infinity, and at the same distance. If all three exposures are equal, the problem is your technique. This is just like statistics: The larger the sample is, the more representative of the whole it is. A wide angle lens takes a large sample of reality (which is presumed to have a reflectance of 18% in most cases). So chances are good that the sample too will approach 18%.Longer lenses make progressively smaller samples, which show more random variation from the global value. The safest course with long lenses is to meter manually, aiming at a part of the subject that has a reflectance approaching 18% or a medium grey tone, or Zone V for followers of that religion. Or, strangely enough, to meter incident light, if the light falling on your back is the same as that on the subject. The old man from the Selenium Age Link to post Share on other sites More sharing options...
bocaburger Posted June 23, 2012 Share #11 Posted June 23, 2012 The Leica TTL meters (excepting the M5) are sort of a center-weighted pattern. I like to think of center-weighted metering as an evaluative/matrix meter with but one single algorithm: small subject in the center of the frame with different brightness from the surroundings. Anything other than that scenario will "fool" the meter...except one: if the entire scene is mid-tone. Therefore, one can get a trustable reading if one fills the entire frame with a mid-tone. Point the camera so the entire frame is filled with medium-green grass, or point it at a clear blue sky 90 degrees away from the sun, and you will get a trustable reading. If neither is possible, set the lens to infinity and point it at the palm of your hand from six inches away (making sure you're not shading your palm with your body or the camera) and add 1.5 stops to the reading. It should be noted that it can always be possible that your final scene is comprised of a contrast range that is outside the capability of film or sensor. You may need to shift your exposure up or down depending on whether you're after detail in the highlights or shadows. Or you may opt to take two shots off a tripod, exposing one for the shadows and the other for the highlights, and combine them in postprocessing. But there is no inherent reason why a 90 or 135 in particular should be problematic. If anything, longer lenses tend to have more even illumination across the field at any aperture than wide lenses, especially at wider apertures. In fact, there have been times when faced with a distant scene, that I popped on a 135 and used it as a spotmeter for a shot I intended making with a 21 or 28. Link to post Share on other sites More sharing options...
WestMichigan Posted June 24, 2012 Author Share #12 Posted June 24, 2012 Hi Boca Burger, Thanks for the refresher info. I have legitimate cause to recheck my thought processes on things even though I'm pretty familiar with meters in camera & out and how to interpret what they're telling me as a photographer. I am starting to be convinced that my erratic over-exposure was due to my Hektor 135's eagerness to flare, however there is definitely an overexposure problem with my camera. I shot with my CV 28 and my CV 75 today and with both lenses the camera was giving me overexposed readings. I am starting to suspect I might have a dirty sensor window (or similar) through which the M8's meter reads the light reflected off the shutter curtain. BTW In past three days I have tried metering off an expanse of grass, metering off dirty concrete, and metering off a medium grey decking material, but all three gave me an erroneous exposure value. I had forgotten about the hand plus 1.5stops trick and will give it a spin sometime soon. Sincerely, I do thank you for the rundown of the meter in the M8 and the metering tips. I do appreciate the input. Richard Link to post Share on other sites More sharing options...
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