wlaidlaw Posted September 10, 2007 Share #1 Posted September 10, 2007 Advertisement (gone after registration) Whereas in general I am delighted with my Tele-Elmar, I have noticed that it seems to have a slight tendency to over-exposure on the M8 - I would guess varying from 1/3 to 2/3 EV and highlights tend to get blown out easily. I am not getting this on other lenses, so I don't think the metering on the M8 is going off. It may just be the way the T-E gathers light and gets it onto the sensor and metering cell. Have any of the other T-E 135 users noticed this? I attach an example, which I have not altered in any way other than to convert the DNG to a TIFF, reduce the mode to 8 bits and resize in CS3. I have not adjusted levels, WB or Exposure. Looking at it, I think I need to reset my manual WB anyway as I have changed from a Leica UV/IR filter to a B+W (the Leica one has gone back on my Elmar 50) and as usual with a B+W it is a bit green. Wilson Link to post Share on other sites More sharing options...
Advertisement Posted September 10, 2007 Posted September 10, 2007 Hi wlaidlaw, Take a look here Over-exposure with Tele-Elmar 135. I'm sure you'll find what you were looking for!
k_g_wolf ✝ Posted September 10, 2007 Share #2 Posted September 10, 2007 The roof, the green ect, look alright for me, but it´s difficult to judge on a screen anyhow. in case you have something so >>contrasty<< in a photo - like the pooltiles - I would compensate a bit - one stop or more towards undexposure - to take care of this. For you pixelexperts: isn´t PHOTOSHOP within a few seconds able to work wonders here ? Best Link to post Share on other sites More sharing options...
jaapv Posted September 10, 2007 Share #3 Posted September 10, 2007 I think ,Wilson, that in this image the dark shadows under the trees of the house are exactly in the centre of the exposure measuring area. That would give rise to some overexposure. I suppose you mean the 4.0. I my case it has no tendency to overexpose. The first-gen 2.8 I owned earlier did overexpose to a certain extent. I'm no pixelexpert, but the exposure slider in C1 would do the trick. Colur-balance, perhaps 200 degrees Kelvin cooler, certainly not more. Link to post Share on other sites More sharing options...
wlaidlaw Posted September 10, 2007 Author Share #4 Posted September 10, 2007 I think ,Wilson, that in this image the dark shadows under the trees of the house are exactly in the centre of the exposure measuring area. That would give rise to some overexposure. I suppose you mean the 4.0. I my case it has no tendency to overexpose. The first-gen 2.8I owned earlier did overexpose to a certain extent. I'm no pixelexpert, but the exposure slider in C1 would do the trick. Colur-balance, perhaps 200 degrees Kelvin cooler, certainly not more. Jaap, The problem I am getting is blown out pixels, which with the 8 bit DNG's can happen quite easily anyway with the M8. Adjusting the exposure post-event does not put any information back onto these pixels, but just darkens them. It may be that the T-E 135/4 has the effect of making the exposure meter more of a spot rather than a center-weighted meter and you have to be more careful to pre-set your exposure for the brightest part of the image and then reframe. I will re-take this shot trying this and see if it works. Wilson Link to post Share on other sites More sharing options...
jaapv Posted September 10, 2007 Share #5 Posted September 10, 2007 Wilson, It seems Bibble has a smart algorithm for that. It is usually just one colour channel that blows out. They use the non-blown out channels to recover detail. I've never used it myself, but it might be worth a try. Link to post Share on other sites More sharing options...
luigi bertolotti Posted September 10, 2007 Share #6 Posted September 10, 2007 The T-E has been the only lens that, sometimes only, given me the impression of a slight over exp, effectively... I also think was someway related to measure angle... but I also remember not to have noticed it if there weren't whites at centre image... anyway, I simply did EV correction (small) in LR... is a function of it, that, imho, works very fine. Link to post Share on other sites More sharing options...
Shootist Posted September 10, 2007 Share #7 Posted September 10, 2007 Advertisement (gone after registration) I see this when going from a 28 or 35 to a 50, 75, 90, and 135. With the 28 or 35 the lense is collecting light from a larger area of the scene then the 50, 75 & so on. I think this is totally normal given the type of metering the M8 has. Link to post Share on other sites More sharing options...
stunsworth Posted September 10, 2007 Share #8 Posted September 10, 2007 The problem I am getting is blown out pixels, which with the 8 bit DNG's can happen quite easily anyway with the M8. A blown out pixel doesn't occur because of the 8 bit coding. You may possibly see a degredation in highlight gradation because of the use of 8 bits, but a blown pixel indicates that the light level was higher than the sensor pixel could cope with, and that would be the case if the file was 8 or 16 bits. Link to post Share on other sites More sharing options...
ho_co Posted September 10, 2007 Share #9 Posted September 10, 2007 ... It may be that the T-E 135/4 has the effect of making the exposure meter more of a spot rather than a center-weighted meter and you have to be more careful to pre-set your exposure for the brightest part of the image and then reframe.... Wilson, I think you have hit the nail on the head. The longer a lens is, the more the M8's meter acts like a 'selective' or 'spot' meter. The shorter the lens, the less 'center-weighted' and the more 'averaging' the meter becomes. To my eye, the exposure is correct if the exposure was set based simply on the area in the center of the above image. I think that as Jaap implied, the problem arises from the fact that the meter sees almost exclusively the center foliage and shadowed part of the house, and doesn't compensate for the brightness of the pool area. --HC Link to post Share on other sites More sharing options...
_©_ Posted October 13, 2007 Share #10 Posted October 13, 2007 I see this when going from a 28 or 35 to a 50, 75, 90, and 135. With the 28 or 35 the lense is collecting light from a larger area of the scene then the 50, 75 & so on.I think this is totally normal given the type of metering the M8 has. that reminds me of the the good ole days of m6 and b/w shooting with neopan 400: on sunny days and with a lens between 21 and 35mm i'd shoot with 100 iso and leave the film in the sauce -2. with 50 to 90 mm i'd set the meter to 200 iso and develop ±0, and with 135mm i'd use 400 iso and ±0 development -- my theory being the same as yours: the wider the angle, the higher contrast will inevitably be. the pool tiles are just the exception that prove the rule as they are about 3 f/stops lighter than the rest of the picture. something that is rare with a 135mm lens, but then again, shit happens... ;-) Link to post Share on other sites More sharing options...
doubice Posted October 13, 2007 Share #11 Posted October 13, 2007 Yes, the 135mm lens will turn the meter of the M8 (or M6 and M7) into almost a spot meter. The M5's meter was a true spot meter and one knew exactly what area the camera measured. With a telephoto lens it is important that one pays good attention to what is in the picture and what might influence the exposure if a careful measurement is not done. Exactly the oposite (underexposure) was reported by users of 15mm and 21mm lenses, where the meter saw more sky and underexposed the foreground. As always - the camera's built-in meter doesn't know what you are exposing for, all it sees is a blob of verying light density - it does not know whether a part of that blob is a bright sky or a dark shadow. I often carry either an 18% gray card or, use a hand-held incident meter in difficult lighting situations. Best, Jan Link to post Share on other sites More sharing options...
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