Luminous Landscape Forum

Equipment & Techniques => Landscape & Nature Photography => Topic started by: flash on September 29, 2003, 07:57:20 pm

Title: EXPOSURE COMPENSATION
Post by: flash on September 29, 2003, 07:57:20 pm
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Perhaps someone could explain the difference between shooting film vs transparency.
Not to be rude, but if beginners read this....... Transparency is still film.

There are two major types of film. Positives (also called transparency, trannys, slides...) and negatives (also called negs, print film...). They are each available in colour and black and white.

When shooting positives you can see the image in its final form by projecting it, or you can have prints made from it. Generally positives have less latitude (they see a narrower range from brightest to darkest) so more care must be taken with exposure when shooting to get it right. Slides generally have more contrast and more useable colours. Slide film is also a faster way to learn about getting correct exposure as your mistakes will be very obvious.

When shooting negatives the image must be printed (or scanned and reversed) for you to see the final image. This means the printer as well as the photographer has an impact on how colours are rendered. Negative film has a wider latitude than positive film so a wider range of tones will be recorded. Many people interpret this as being a licence to let the film cover any errors in setting correct exposure. If you get all you printing done at cheap labs you might as well as they and you are not really getting all the information available on your film. However to get the best results from negatives you need to get your exposure right just like sllide film. Then a good printer can get awesome results for you. Learning exposure using negatives takes more times as small differences can be compensated for by the person printing your pictures. You also rely on them to choose your colour palette.

Jump off soap box.

In John Shaw's books he describes correct exposure as getting the scene exposed as you wanted it to be. I like this as it means if you want a scene that is light in reality to look dark on film, fine. It's all up to you. So you compose you subject and decide what tone it is going to have.

Your camera, wonderful thing it is, is not capable of making a subjective decision like this. Even with its 35 metering zones etc it still is not capable of seeing a scene the way YOU want it to be. It measures every scene for the average.

If you decide a scene should be darker (or lighter) than average then this is when you can use exposure compensation. We all used to have to revert to manual (and we still can) to have total control over exposure. Now we can simply dial in the difference we want.

Everone uses the example of a white wall and how the meter sees it a mid grey and you need to add exposure to make it appear white on film. While this is true, its been quite a while since I photographed a blank white wall. I prefer to think of the mood I want to create.

I know how my camera meter sees a subject (experience) and I make a decision as to whether I agree or dissagree with the recommended settings. If I disagree then I use exposure compensation. I never assume that my camera will see the world the way I want it to be seen. For example if I know I want a sillouette and I also know my cameras meter will try to make the same subject a mid tone, I will use exposure compensation to make sure my subject is the very dark tone I wanted.

It takes time and some film to learn how your camera meter thinks and when you need to overide its decision. Keep shooting and analysing and it will come to you.

Gordon
Title: EXPOSURE COMPENSATION
Post by: Bob Stevenson on October 01, 2003, 03:10:03 am
Just an 'aside' really;

Reading the answers to andrew's questions has been 'cumpulsive viewing' for me and reminded me of when I moved up from the Box Brownie to an old folder 'with numbers'!

I was wondering if Michael could find a few spare minutes (grin) to edit some of these excellent answers into one of his tutorials,...it would be a great asset to this site.
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on October 17, 2003, 09:29:52 am
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... and in manual mode it will only affect your meter reading.
willowroot,

So, do you mean the exposure "change" will only be displayed in the meter reading, and won't actually change the Tv or Av until the shutter button has been activated?
Title: EXPOSURE COMPENSATION
Post by: francois on October 18, 2003, 06:27:52 am
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Can exposure compensation even be used in manual mode?

I'm not sure about the situation on an Elan-7 (EOS 33), but on EOS-1/3 (any flavour: 1v, 1Ds, 1D), using your camera in M disables any compensation you've set in Tv or Av mode. Returning to Tv or Av mode re-enables the previously set exposure compensation.

So, exposure compensation cannot be used in Manual mode. It makes sense as exposure compensation is a manual correction.

It's [exposure correction/compensation] only useful when you want to override the automatically calculated exposure in Tv or Av modes.

You should understand exposure correction as a way to fine tune the parameter choosen by the internal computer/meter of your camera.

francois
Title: EXPOSURE COMPENSATION
Post by: victoraberdeen on October 21, 2003, 12:21:38 am
If you find Michael's exposure article a little too technical, take a look at Light metering onthe Photozone... (http://www.photozone.de/bindex4.html)

Enjoy
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on November 07, 2003, 02:20:23 am
I have another query...

I saw a picture in a photo magazine of a bridge over water during a yellow sunset; which was part of a little centerfold titled 10 tips to better pictures. This particular tip was trying to illustrate the effects exposure compensation can achieve for a photo... the bridge was coated in the golden glow of the sunset, yet the arcs were dark almost a pure black; i can't really tell as it was quite a small picture...the little caption said this was done by underexposing.
But when i underexpose something, it tends to come out a greyish colour revealing alot of grain...???
perhaps i'll scan this image, but i don't have a website to post it on....
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on September 29, 2003, 12:13:50 am
G'day

I have recently purchased a Canon Elan-7 EOS 33!

Anyway. I have read through the whole manual (all in one night from my excitement!:D) I got abit confused with "Exposure Compensation". What confused me was the fact that the camera was clever enough to tell me the standard correct exposure in the viewfinder and on the LCD screen... and that you could change the exposure if you wanted.  Why?  Why would you want to change the correct exposure?
Wouldn't it be better to use AEB?

Andrew
Title: EXPOSURE COMPENSATION
Post by: d2frette on September 29, 2003, 10:32:06 am
Perhaps someone could explain the difference between shooting film vs transparency.  I know that shooting transparency: you get what you shoot.   And that shooting film: you get what you shoot combined with how it's developed.  Something to that effect.  I've never shot transparency.  

I do know that at a low quality labs (WalMart, Target, ...) they take an average exposure to your roll of negatives and then process them based on that.  So, if you shoot film, you should spend the extra money and take it to a higher quality lab.  

You get what you pay for!

-Dave
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on September 30, 2003, 10:53:14 am
G'day

I now understand that exposure compensation can be useful when photographing snow or sand in bright daylight conditions. But could someone set up a scenario which i am more common with where exposure compensation is also used?  Such as landscapes or macro etc.?

Thank you
Andrew

I'm sorry that i posted this question in here... i should have posted in a broader category... But everyone is quick to answer and everyone is incredibly helpful!
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on September 30, 2003, 11:26:11 pm
So it all comes down to experience, experience, and some more experience... !!

Thanks to everyone who replied.

I'll be sure to check in the library at school for more in depth info first thing on monday!

Andrew
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on October 01, 2003, 04:34:00 am
Agreed!  :)

All in favour?
Title: EXPOSURE COMPENSATION
Post by: Gordon J. Millar on October 01, 2003, 08:33:06 am
Agreed!
Title: EXPOSURE COMPENSATION
Post by: Willowroot on October 17, 2003, 09:21:37 am
Depends on what metering mode you're in.  In shutter priority, + compensation will open the aperture further.  In aperture priority, + compensation will increase the time the shutter is open.  In program mode it will do both and in manual mode it will only affect your meter reading.

Jason
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on October 17, 2003, 09:36:33 pm
G'day

Thanks for your reponse, francois (i meant no offence last time when i said you didn't help - my fault! )

Willowroot, I don't quite understand what you're trying to say... actually, i have no idea sorry... could you just put it in different words?  
Can exposure compensation even be used in manual mode?
Cos on my Canon Elan-7 (EOS 33), i have a quick control dial which controls Tv, and the other dial which controls Av...
I'm sorry, i've confused myself even more now.

Okay...
If i am in Tv priority, and i turn the dial that controls Tv, then the Tv changes, and if i turn the "other dial" (after pressing the shutter button halfway) the Av changes, and also changing the exposure meter reading.

If i am in Av priority, and i turn the dial that controls Av, then the Av changes, and if i turn the "other dial" (after pressing the shutter button halfway) the Tv changes, and also changing the exposure meter reading.

If i am in manual mode, and i turn the dial that controls Av, then the Av changes, and if i turn the "other dial", the Tv changes. So does this mean Exposure compensation cannot be used in manual mode, because there are no other dials to turn?

Andrew
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on October 20, 2003, 05:13:44 am
G'day Francois,

Quote
You should understand exposure correction as a way to fine tune the parameter choosen by the internal computer/meter of your camera.

Could you explain in greater depth what you mean by that sentence and what situations you would use it?
Thanks

Andrew
Title: EXPOSURE COMPENSATION
Post by: Willowroot on October 20, 2003, 09:44:52 am
Quote
Quote
Can exposure compensation even be used in manual mode?

I'm not sure about the situation on an Elan-7 (EOS 33), but on EOS-1/3 (any flavour: 1v, 1Ds, 1D), using your camera in M disables any compensation you've set in Tv or Av mode. Returning to Tv or Av mode re-enables the previously set exposure compensation.
Hm, so what I said probably wasn't right anyway (was thinking about how my Minoltas work) - just as well you couldn't understand it then  ::

Jason
Title: EXPOSURE COMPENSATION
Post by: BJL on November 07, 2003, 09:12:16 am
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But when i underexpose something, it tends to come out a greyish colour revealing alot of grain...???
perhaps i'll scan this image, but i don't have a website to post it on....
That sounds like the problem I get with minilab prints from some negatives: if I deliberately take a darkish ("underexposed") image, the automated processing brings the overall lightness up to average, to "correct my mistake", which causes areas that are meant to be dark to be pushed up to near mid tones. At that level, one is seeing severely reduced contrast due to a combination of the film's flatter contrast response at low light levels, lens flare (stray light from brighter parts of the subject reaching the darker parts of the image) and maybe even underlying film fog.
   This is why the practice of exposure compensation skills with a film camera must be done with slides, where the development involves no adjustments.
Title: EXPOSURE COMPENSATION
Post by: francois on October 17, 2003, 11:00:55 am
Andrew,

In others words:

If you set your camera in aperture priority mode, set your aperture at f/5.6 an get a reading of 1/250, then a +1 stop compensation will change your speed from 1/250 to 1/125 (or twice as long).

This change of speed is reflected in the viewfinder reading [at least in my EOS].

If I press the shutter button and then turn the back dial  to introduce some positive or negative exposure compensation then changes are displayed even if I release the shutter button.

francois

PS: I hope this time I have understood you correctly  
Title: EXPOSURE COMPENSATION
Post by: francois on October 21, 2003, 04:01:45 am
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If you find Michael's exposure article a little too technical, take a look at Light metering onthe Photozone...

The Photozone article is maybe more accessible and illustrated with a bunch of pics. Andrew, you should really spend some time on that article (and on Michael's tutorial as well).

Good luck,


francois
Title: EXPOSURE COMPENSATION
Post by: francois on October 21, 2003, 09:14:51 am
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Can't i use slide film?  
Or were you implying i am capable of using slide?

You're not likely to see much difference between shots made with or without exposure correction if you use print film.

Quote
I saw you're using an Elan-7 (EOS 33) camera!

I wanted to avoid other forum users to step-in and say that digital can do it too!

francois
Title: EXPOSURE COMPENSATION
Post by: Jeff Donald on November 08, 2003, 07:57:11 am
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Can the people who develope my photos override this automated processing system?

Some labs can and some can't.  It depends on the equipment being used and the training of the personnel operating it.  Your question is best directed to the lab you use for processing.
Title: EXPOSURE COMPENSATION
Post by: mebow on November 27, 2003, 01:58:01 am
For additional reading try this page

http://www.photozone.de/bindex4.html (http://www.photozone.de/bindex4.html)

good luck. Mike
Title: EXPOSURE COMPENSATION
Post by: Aaron Reynolds on September 29, 2003, 01:46:11 am
Andrew,

The light meter in your camera works on the assumption that your subject is neutral mid-tone grey so if you are photographing snow or very white sand for example then the exposure determined by the camera will render it darker than it appears in reality. This is where the photographer must intervene by dialing in an appropriate amount of exposure compensation. This is easier once you are familiar with the idiosyncracies of your camera's light meter. The best way to learn is to shoot a roll of your favourite transparency film on a few different scenes, dialing in varying amounts of exposure compensation and taking detailed notes with a pencil and paper. There are also many great books and resources on the web if you search for the "simplified zone system." Best of luck and welcome to the wonderful world of photography.
Title: EXPOSURE COMPENSATION
Post by: Joe Hardesty on September 30, 2003, 01:36:03 pm
Andrew,

Don't get hung up thinking about snow and sand--those were only examples. Think about it this way:

Your camera meter is giving you the proper exposure based on the metered area being approximately the same light value as middle gray. If you are shooting general landscapes, flowers, houses, or even light-skinned people, this value is fairly accurate, but in other cases it is not.

If you point it at a white lilly, the camera says "OK, you want the lilly to be middle gray". If you point it at a black dog, the meter says "OK, you want the dog to be gray". In these cases, you have to compensate for the meter's thinking. Light measurements are all about shades of gray and not about color.

If you want to know what middle gray looks like, go into photoshop and fill a new document with a color that is R=192 G=192 B=192. That is middle gray.

Now take some of your photos and convert them to grayscale images and you should be able to see how the camera views light values. Look for areas of the photo that are like the 192-192-192 document you made and you should see that they are in the general center of the exposure.

This is one of the most important concepts in photography. I suggest you do some experiments to see exactly how it works. Take some bracketed shots of white and black objects to see how the camera handles them. In reality, bracketing is just a lazy method of exposure compensation.
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on October 17, 2003, 07:59:29 am
G'day


I'd just like to thank everyone again for their reply.
I still need some basic information on exposure compensation:
-more light can be let in by opening up the aperture (&vice versa)...
-a longer Tv will pro-long the entrance of light (&vice versa)...
-exposure compensation...?

What exactly does exposure compensation do to the settings?
What goes on in the camera when you set exposure compensation higher or lower?

Andrew
Title: EXPOSURE COMPENSATION
Post by: Willowroot on October 17, 2003, 04:02:12 pm
Quote
Quote
... and in manual mode it will only affect your meter reading.
willowroot,

So, do you mean the exposure "change" will only be displayed in the meter reading, and won't actually change the Tv or Av until the shutter button has been activated?
No, it won't change the Tv or Av at all in manual mode, since you're the one that's controlling them . . . put it this way, if you are metering a scene and you have your settings at 1/30 and f/5.6, and the meter says that is right, when you dial in +1 stop compensation, your meter will now tell you your settings are underexposing by 1 stop - so now you set the shutter to 1/15 (or your aperture to f/4) and it will show you that your exposure is correct again.  Hope that made some kind of sense . . .

Jason
Title: EXPOSURE COMPENSATION
Post by: francois on October 20, 2003, 05:59:17 am
Andrew,
When you choose Av or Tv mode you are imposing a specific value to your camera. In Av mode (aperture priority) you decide what aperture value you want to use then your camera will automatically give you a speed value resulting in a "correct" exposure. This is why it's called Aperture Priority! In Tv (time value or shutter speed) mode, you decide to set shutter speed and then your camera gives you an aperture value.

Exposure correction/compensation modifies the value computed by your camera while leaving aperture (in Av) or shutter speed (in Tv) as you set it.

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what situations you would use it?

Generally, you use compensation for difficult or complex subjects such as snow, white sands, lava beds, heavy backlit situations. This is true for scene that are not middle-toned.
In other words when you feel that your camera meter will be fooled.
Other situations are when you want to have a personal spin to your photos. Sometimes you want to under-expose to get darker photos and more deeply saturated colors.

Michael has an excellent tutorial about exposure. (http://www.luminous-landscape.com/tutorials/understanding-series/understandexposure.shtml)

By the way, use slides to experiment.

Hope this helps - write back if it doesn't.

Francois
Title: EXPOSURE COMPENSATION
Post by: francois on October 20, 2003, 06:06:45 am
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By the way, use slides to experiment.

I saw you're using an Elan-7 (EOS 33) camera!

francois
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on October 21, 2003, 05:48:34 am
Quote
Quote
By the way, use slides to experiment.

I saw you're using an Elan-7 (EOS 33) camera!
Francois, what do you mean?

Can't i use slide film?  
Or were you implying i am capable of using slide?
Andrew
Title: EXPOSURE COMPENSATION
Post by: -Andrew- on November 07, 2003, 09:14:57 pm
BJL,

Quote
the automated processing brings the overall lightness up to average, to "correct my mistake"

Can the poeple who develope my photos override this automated processing system?