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#1 |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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Hi,
I havea problem mastering this particular kind of shot where I take in scenery with a person in the foreground. Now what happens is that the udnerexposure occurs when the lighting is bad - ie. the sky is overcast or filled with lots of white and very bright clouds. This gives off lots of specular reflections and causes the camera to be fooled into the thinking that the scene is brighter than it really is. Hence whatever subject is in the foreground - person, animal or building gets underexposed to varying degrees depending on the colour of the subject. The darker the subject, the worse the underexposure. I understand that if I crop of the sky, then the problem solves itself but in ertain scenes, u want a bit of the sky or want 1/2 your photo to contain the sky. Anyone can help me with a simple solution? I was using a Minolta 505si on Aperture priority on f/11 - f/22 with a circular polariser. Now shots where the sky is a beautiful blue) like in postcards do not exhibit this problem at all. With human subjects, as they are nearer, the flash is used to expose them correctly but what happens is that the picture looks as if there is no flash. With buildings, that is not possible so they look even worse. Usually when I leave my flash on at f/11 or smaller, the shutter spped is at 1/125 sec or faster but the camera keeps telling me that it is too slow still! Does the circular polariser affect the shot and cause it to be underexposed? I fancy that the shot turns out worse without the polariser since it effectively acts a ND filter to reduce the light by 2 stops. I have tried such shots in the past without a polariser but the shots looked very very washed out. So any ideas? Sorry I have no photos to show as I haven't have a website where I can link photos. Maybe someone can give a url to a good host? Geocities does not allow hosting unfortunately and that is where my first website is! ![]() |
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#2 | |
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Senior Member
Join Date: Jan 2002
Location: Singapore
Posts: 6,597
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Your problem is backlight. Fill flash will help for people shots. For fill flash, it's supposed to be subtle and not very obvious, so nothing wrong there. For shots which your flash cannot reach, you might want to dial in some exposure compensation. The amount has to be experimented. CP will not cause the film to be underexposed. Your camera meter will compensate automatically. Regards CK |
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#3 |
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Member
Join Date: Jan 2002
Posts: 385
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Ming Ern,
Long time no see! Meter the brightest portion of the sky followed by the darkest part of the scene...then take the average...that is what i do usually when i am not sure about the exposure... Fill flash is a must for pple shots against a sunlit sky or even overcast sky... Underexposure is always better than overexposure...rememeber that...(at least for digital photography!) |
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#4 | |
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Senior Member
Join Date: Jan 2002
Location: Singapore
Posts: 6,597
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Hmmm..... Ming Ern sounds so familiar.... dunno where I've seen this name before.... Regards CK |
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#5 |
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Member
Join Date: Jan 2002
Location: Singapore
Posts: 487
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Two basic situations,
1) Shooting with the sun behind you, both the subject and the background should be within the latitute of the film. 2) For backlighting, meter for the background, then open up your aperture to f4, focus on the subject at 3 meter and use fill flash. At f11 - f22 fill flash is way too short (GN 12/11 = 1.1 meter, GN 12/22 = 0.55 meter), use a reflector will be a more appropriate choice. Flash should not be used with small aperture unless for marco. |
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#6 | |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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As for flash not being used for small apertures, I guess it applies only if the subject is quite some ditance from you. Otherwise, the fill flash is still necessary for correct illumination of the face of a person, let's say, in bright harsh lighting conditions. As point (1), could u explain what the latitude of the film is? I don't understand what u are trying to tell me there. Thanks! As for point (2), could u explain the rational for doing so? I also don't quite get it. Exposing at f/4 would mean that the background is blur which is notwhat I want to achieve. |
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#7 | |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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How do u determine the average? I use aperture priority and let's say I set the aperture at f/22 and the shutter speed is 1/125. No my shot turns out such that the whole white sky background is exposed properly while the foreground and other scenery is a dark brown. Obviously underexposed? So how to take an average here? Average of the aperture of the shutter speeds? I tried spot metering on the dark areas but it always gave me very rather low shutter speeds. For example under bright white sky, I metered the subject's brown jacket or face at f/22, the former gave me 1/20 while the latter gives 1/45. So this doesn't work and seems rather ridiculous to use a tripod under bright conditions!! Thanks for your suggestions! Maybe some in depth explanation for a novice for me is in order. ![]() |
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#8 | |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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I thought that this might be a solution but I can't make out which is what on the EV scale! Is +1.5 opening of closing the aperture? Since +1.5 is either opening or closing down 1 1/2 stops, if I am at f/9 for example, then how to calculate what the final aperture is? And does the shutter speed change when EV is dialed in? I noticed that in an experiment, again at f/22, without EV, the shutter speed was 4 s, but with EV +2.0, it is 1s. Can explain what is going on? And if I am at the maximum and minimum aperture limits of my lens, can I stop down or open up some more whichever is applicable? Let's say I use the Tamron 24-135 and at 100mm, the maximum aperture is f/4.0, can I open up some more using aperture compensation? Is it possible?! Thanks! |
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#9 |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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Thanks for all your replies, it seems that I have a number of options at hand to tackle this problem but it seems that I don't understand what most ou are trying to teach me. Hope u can explain a bit more! Thanks!
ckiang, why is my name familiar? I was from NUS Science Chemistry if that rings a bell. |
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#10 | |
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Senior Member
Join Date: Jan 2002
Location: Singapore
Posts: 6,597
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+1.5EV is 1 1/2 stop more exposure. If you are in Aperture Priority, this means the camera will select an aperture which is 1 1/2 stop above what it will select at EV 0. Which means if you are at aperture priorty and set an aperture of f/8 which gives a reading of 1/250, setting +1.5EV will result in a shutter speed of 1/250 - 1.5 stop which is about 1/80. You mentioned above you use f/22, way too small. Open it up to f/11 or so, and you won't have the ridiculous shutter speed of 1/40. At f/16, you should be able to get a decent Depth of Field at usual subject distances. For your Tamron, if you are at Aperture Priority and are using 100mm at f/4, increasing exposure compensation will result in the camera varying shutter speed. At shutter priority, the adjustment will be made using the aperture. If the camera cannot choose a wider aperture than you len's maximum at the chosen shutter speed, underexposure will result. At program, dunno. Depends. For your case, it looks like it is fooled by the bright sky more than anything else. Regards CK |
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#11 | |
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Senior Member
Join Date: Jan 2002
Location: Singapore
Posts: 6,597
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Regards CK |
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#12 | |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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#13 | |
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Senior Member
Join Date: Jan 2002
Location: Singapore
Posts: 6,597
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![]() Regards CK |
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#14 | |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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I agree that the camera's weighted metering was fooled by the bright sky. Hence there is a need to compensate for it. The question is of course how and by how much. Any idea how spot metering works in such a situation? U might want to read one of the above posts to see what my results were - varying in degrees of success. I haven't really compared the sharpness at f/11 and f22. So I thought that to get pin-sharp backgrounds, then u need f/22. Will try more shots at f/11 then to find out. I kept getting rather slow speeds at 1/60 sec, 1/45 or 1/30 or 1/20. I get sharp shot sfor all except 1/20 sec where camera shake gets really obvious. 1/30 is still acceptable but it could have been sharper. I generally prefer at least 1/90 sec for sharpness though. So if f/11-f/16 works for backgrounds then my shutter speed problem is solved lah! Thanks for your very useful input! |
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#15 |
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Member
Join Date: Jan 2002
Posts: 385
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I use f8 and above usually if i take landscape shots...if it is like very sunny, then i will use f11 or f16...
What i meant in the beginning of averaging is by metering the brightest and dimmest spots, you will get a rough guide as to how much exposure is required... Put it this way, for example, if you meter off the sky and it gives a reading of 1/500, f8 and the dimmest will give a 1/125, f8, then maybe you would want to use a setting of 1/250, f8...this will ensure some sky details will be kept without overexposing and also at the same time the dimmer parts of the scene will be properly exposed.... As to how much you want to compensate is up to you...if the sky is not your main aim, then perhaps overexposing is a better choice as you would be able to capture the darker portions of the scene...and of course, vice versa... I hope i said this rite... |
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#16 | |
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Member
Join Date: Jan 2002
Posts: 385
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#17 |
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Member
Join Date: Jan 2002
Location: Singapore
Posts: 487
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Please try to understand this line. This should solve your problem.
"At f11 - f22 fill flash is way too short (GN 12/11 = 1.1 meter, GN 12/22 = 0.55 meter), use a reflector will be a more appropriate choice." Your flash range drops by half every time you reduce the aperture size by two stops, thus range is limited by the Flash Guide no. and the aperture used. A reflector will provide constant light throughout the exposure thus not affected by any exposure combination. In short, use a reflector if you want to fill in your subject at f22. Latitude = http://photographytips.com/page.cfm/199 |
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#18 |
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Senior Member
Join Date: Apr 2002
Posts: 2,638
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erm.. wat u ppl mean by metering the brightest part of the sky and the darkest part of the pic to take the average?
how to do that? use wat type of metering? issit the half press method? |
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#19 |
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Member
Join Date: Jan 2002
Posts: 385
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Yup, just use your camera's in built meter...
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#20 | |
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Senior Member
Join Date: Jan 2002
Location: Clementi
Posts: 6,188
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