How to avoid overexpose and reflection with mid-day sun?


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Jul 23, 2005
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#1
Hi,

Was trying to get a good shot of the temple today at around 1pm.
Sun was strong. CPL didn't have any effect on reducing the reflection
on the golden dome at all.

Photo taken using Canon 350D and Sigma 28-300mm lens. Settings as follows:
- ISO 100
- Focal Length = 86mm
- Av = 9.0
- Tv = 1/250

Appreciate if experts here can share some tips on how to improve
quality of this kind of shots.

Picture was cropped, and reduced resolution to enable upload
(how can I upload > 100kbyte photo?)

Please post your suggestions here. Thanks!

 

Nov 12, 2003
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#2
i'm no expert... but it seems it would be quite diffcuilt to capture a properly exposed picture espcially when the range of bright and dark is so vast...

i.e, details in the stone relif vs. details in the shadowy areas of the windows, statues and so on....


What I would do is to bracket my shots, over exposing(+) and underexposing(-) by 1 stop then digitally merge the pictures to achive what i think is known as a bigger dynamic range

This also works great on pics that require parts of the sky in the picture, as often the sky blows out...


What i think is needed would be:
A tripod
and i would use the time value to bracket, and keep my apature constant (i prefer a large F-stop in this case)


hope it helps!
 

jamesong

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May 23, 2002
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#3
Why do you choose to shoot in mid-day with the sun blazing down on your camera? Why, set yourself with this problem?
Are you doing a test on your camera?

The best time to shoot is morning before the sun becomes intense and afternoon after the sun about to set.Photographers always avoid the blazing sun.:)

Choose a good day to shoot.:cool:
 

~Arcanic~

Senior Member
Feb 27, 2005
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#4
both james and moo has said the main point..

but if u really have to take a shot at the very bright sunlight, then i guess bracketing and PS is the way to go ba..
 

surge

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#5
since you are shooting digital and its a non moving subj, shoot on tripod 2 shots. one exposure for the shadow area and the other for the highlight area. then just combine them together. if your intention is to capture the temple, i think can underexpose the dome soc even if the shadow area is under, it doesnt matter. if fact the come will stand out better due to the contrast:)
 

Jan 23, 2005
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#6
ConnorMcLeod said:
CPL didn't have any effect on reducing the reflection
on the golden dome at all.
This is not surprising. Metallic reflexes are not strongly polarised.

Sorry if this sounds trivial: to avoid overexposure, expose less. Meter for the highlights to avoid burned out areas. It is worth noting that exposure metering techniques carried over from negative film are prone to failure: negative film cannot tolerate underexposure (the ISO rating is based on the minimum exposure that will yield a usable image), but a lot of overexposure (the ISO rating doesn't say anything about much light the film can handle). With digital, it's the other way round.

Pay attention to the histogram. A picture of such a high contrast scene that isn't overexposed _will_ look dark; managing the contrast has to be done by adjusting curves in postprocessing. (The "low contrast" settings in the camera help a bit, but they are cumbersome to use and fairly inflexible).

To avoid posterisation, it is highly advisable to record the picture in raw format.

Picture was cropped, and reduced resolution to enable upload
(how can I upload > 100kbyte photo?)
I think ClubSnap limits the file size to 100 kB. You can remove the EXIF information from the image files to make them smaller without any loss in image quality. Also note that posting EXIF information in the pictures can be a privacy issue - it may contain information like your name, etc.
 

Jul 23, 2005
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#7
jamesong said:
Why do you choose to shoot in mid-day with the sun blazing down on your camera? Why, set yourself with this problem?
Are you doing a test on your camera?

The best time to shoot is morning before the sun becomes intense and afternoon after the sun about to set.Photographers always avoid the blazing sun.:)

Choose a good day to shoot.:cool:
No reason to shoot at mid-day in this particular case, just to find more opportunities to learn the camera. Indeed I also don't like walking around under strong sun :p

Now I've learned not shoot under strong sunlight condition and the bracketing tricks! :) Thanks to all the constructive comments from everyone!
 

Jul 23, 2005
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#8
LittleWolf said:
This is not surprising. Metallic reflexes are not strongly polarised.

To avoid posterisation, it is highly advisable to record the picture in raw format.
Hi LittleWolf,

Since metallic reflections are not strongly polarised, is there a way to reduce the reflections
of the spot lights off the body of cars in car show? (I suppose I cannot turn off the lights ;) )

What is posterisation?

Thanks! CM.
 

Jan 23, 2005
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#9
ConnorMcLeod said:
Since metallic reflections are not strongly polarised, is there a way to reduce the reflections
of the spot lights off the body of cars in car show? (I suppose I cannot turn off the lights ;) )
As a normal visitor to the car show, probably not. The solutions I can think of fall in two classes:

1) Control reflections e.g. using polarised light sources plus a polariser on the camera. The necessary lighting equipment may make this not too practical.

2) Modify the reflective surface. I haven't tried it, but spray-on montage adhesive as used by graphics designers could work to make the surface appear matte. I doubt though that security will let you do this :).

What is posterisation?
The pixels in digital images can take only certain values (colours, brightness). If this "palette" has enough colours, gradients in the picture appear smooth (colour/brightness steps are small enough to be imperceptible).

Operations such as changing the contrast can affect the "step size" between available colours. If the "step size" happens to be increased and you happen to start out with a small palette, the steps can become visible to the naked eye. This looks similar to a certain style of posters printed using only a small set of colours/tones, hence "posterization".

Compression methods like JPEG work essentially by keeping only the minimum image information needed to give a good looking approximation of the image - i.e. they throw away "invisible" image details. When you do image processing, the "invisible" details are made visible - except they have been removed before. This leads to multiple ugly artefacts, of which posterisation is one. (Also, even before compression, common JPEG starts out with 8 bits/pixel worth of luminance data, which is marginal for any kind of processing.)

There are JPEG variants that would solve many of these problems In particular, JPEG with 12 bits/pixel luminance is an established standard that would match digital cameras very well. For reasons unknown to me, camera manufacturers don't implement it.
 

Jul 23, 2005
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Singapore, West
#10
Hi LittleWolf,

I still think causing a power failure at a car show is easier.
Otherwise I simply shoot only the models whom are usually less prone to reflections :p

Thanks for your detail explanation on posterisation. From your description, posterisation is independent of image compression though lossy compression can further deteriorate the quality of the image. Better shoot with RAW mode from now on :)

Well, years ago people already spoke of JPEG2000 (think it was around '97) and I have not really heard much about it. Compatibility is scapegoat?
 

Jan 23, 2005
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#12
ConnorMcLeod said:
Well, years ago people already spoke of JPEG2000 (think it was around '97) and I have not really heard much about it. Compatibility is scapegoat?
I think there's some concern about intellectual property problems. Some companies may hold relevant patents and, once JPEG2000 gets widely accepted, they might try to start cashing in. Classic example how the "IP" buzzword impedes progress. (In fact, one obscure company is trying to cash in -- and partially succeeding in that -- on common JPEG).
 

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