Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
02-17-2022, 01:37 PM   #1
New Member




Join Date: Feb 2022
Posts: 4
Exposure Compensation Confusion

Ok, so I read many articles about Exposure Compensation. I searched for the topic on the forum. I found some old topics. Therefore I'm starting a new one instead of opening the really old one.

1st, don't laugh please! It's my first DSLR, I'm new in this world and I'm a self-taught.

Here we go. I setup my new K70. I don't want to use Auto mode or Scenery one. I have iPhone's camera for this. My DSLR should give me a fun when using it.
So, I decided to use TAv mode. I love changing aperture and shutter speed to meet my requirements. And I let the camera handle ISO. Thank you so much Pentax for giving us TAv. I read a lot about Exposure Compensation. And now I'm so confused

When I'm in TAv mode and I change Exposure Compensation for minus or for plus, I can see that it changes aperture or shutter speed or those both values. In Tv or Av it changes one of those parameteres. So my big question is: why should I use that "-/+" button to change EV stops when I just can set shutter speed and/or aperture manually to get desired image and histogram? If I set aperture and shutter speed to get proper exposure, is it necessary to use Exposure Compernsation at all? I take a picture, look at histogram. If I want to make changes, I change shutter speed or aperture, also trying to get the lowest possible ISO. All of that to make sure my photo is properly exposed. So why should I use Exposure Compensation feature?

Ok, have you stopped laughing? Can you explain it to me? Maybe there is a hidden extra feature that I just don't get?

02-17-2022, 01:53 PM   #2
Veteran Member
bertwert's Avatar

Join Date: Jun 2015
Location: Golden, BC
Posts: 15,173
Alright, so exposure compensation is a very useful capability. It's effectively setting the new 0 on the exposure meter. Say, you're taking a photo of snow - this is very white and bright, and the meter ends up under exposing the scene, so you set exposure compensation to +1.5 or so to get a well exposed photo.

In automatic or semi-automatic modes (P, Av, Tv, TAv) it's what you set when you find the exposure is too bright or dark. Without exposure compensation, the camera would always have the brightness where it thinks it right, or you would have to go in to manual mode to counteract this.

Welcome to the forum, and keep asking away - it's a great place to learn here!
02-17-2022, 01:58 PM - 1 Like   #3
Site Supporter
Site Supporter




Join Date: Jan 2010
Location: Netherlands
Photos: Gallery
Posts: 437
One very simple example, a bird in flight. Without exposure compensation, you will see a silhouette of the bird without detail.
You're camera will look at the general brightness of the image, but you want the bird at a right exposure, so you have to 'fool' you're camera and let is 'think' everything is a lot less bright, so the bird get a exposure so you can see more than a silhouette.

And, no one is gonna laugh, everybody started once.

So keep asking en ALWAYS keep in mind, "There aren't stupid questions, only stupid answers".
02-17-2022, 02:01 PM - 1 Like   #4
Pentaxian




Join Date: Jul 2016
Posts: 586
Hello.

TAv mode, exposure compensation changes the ISO. As Tv and Av are fixed, only ISO can be changed make the image darker or brighter.
While in TAv mode, when you change Tv or Av, ISO is changed automatically to keep the 'correct' exposure.

Regards.

02-17-2022, 02:12 PM - 1 Like   #5
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jul 2021
Location: Zuiderkempen - Grote Netewoud - Belgium
Photos: Gallery | Albums
Posts: 1,350
The camera measures the light of the scene, it’s an average... to adjust settings. Works fine in most situations.
If you have dark or light extremes in a scene , you can deviate from the average by setting ev to align more with the darker or lighter part of your scene.
A bird against a bright sky is typically under exposed , so one might tune to get bird right and overexpose sky....
One might compensate for shadow areas, sunsets, northern light, ....
Or you might want to stress the darkness of the evening scene and underexpose a bit (the camera might push up too much so that it looks like a day scene...)


There are other options :
You can set the camera to measure light only in center area or center point ( hopefully the birds Location, if it is a bird in flight this might be difficult, so the above +/- might be easier.. ).
Or you can go fully manual...

But +/-ev is quick correction.
02-17-2022, 02:41 PM - 1 Like   #6
Moderator
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 8,109
QuoteOriginally posted by To_Omek Quote
When I'm in TAv mode and I change Exposure Compensation for minus or for plus, I can see that it changes aperture or shutter speed or those both values. In Tv or Av it changes one of those parameteres. So my big question is: why should I use that "-/+" button to change EV stops when I just can set shutter speed and/or aperture manually to get desired image and histogram? If I set aperture and shutter speed to get proper exposure, is it necessary to use Exposure Compernsation at all? I take a picture, look at histogram. If I want to make changes, I change shutter speed or aperture, also trying to get the lowest possible ISO. All of that to make sure my photo is properly exposed. So why should I use Exposure Compensation feature?
Think about it like this :

When you use a camera meter you are using a reflective reading, so your meter result is based on the brightness/reflectiveness of your subject. Take a picture of a black cat against a black background and your meter reading will be wrong. Same for a white cat against snow. In early days of cameras, before Av or Tv came along you would allow for this by over/underexposing your image using the aperture and shutter speed. Now wind on a few decades and you use a mode like Av. Now your black cat is moving around in changing light but is still always against a black background. So you know you need to underexpose the image by two stops....then you set your EC to -2 and you get correctly exposed images. Some may be at f5.6 at 1/100 and some may be at f5.6 at 1/400, but they are all correctly exposed. This is where EC works very well.

You are correct that EC cannot give you anything more than Manual exposure can for the same scene. But if your subject is moving in changing light it can be a very good aid to your photography.


QuoteOriginally posted by To_Omek Quote
Ok, have you stopped laughing?
Most members of this forum would not dream of laughing at an intelligent question such as you have posed. Welcome to the forums. With your enquiring mind you will do very well at photography.
02-17-2022, 02:57 PM   #7
Senior Member




Join Date: Jul 2017
Photos: Gallery
Posts: 280
To really understand what the exposure compensation is doing, you want to look at your iso, shutter speed and aperture. I do mostly landscape photography, so I use Av mode to set my aperture to something like f/13 and set my iso to 200 for low noise and let the camera pick my shutter speed, say 1/250 second. If I adjust the aperture to f/8, the camera will increase the shutter speed up to something like 1/500 sec to get the same exposure (same picture brightness).

However, if I am at f/13 and iso 200 and want a brighter picture (over-expose) then I change the exposure compensation to +1 and I will see the camera change the shutter speed to 1/125 second to provide a longer exposure and give me a brighter picture.

You need to look at iso, aperture, shutter speed and exposure compensation and see how the different settings change as you change one setting. Also make big changes like +2 compensation so the change is big enough to see the effect on the other settings.

The nice thing is that the camera will record all you settings for each picture. When I learned in the film days, I had to carry around a little notebook and write down the settings. Then I would wait a week for my pictures to be developed and go back to my notebook to see what my settings were for the good pictures. If you really want to learn how the camera works, look at all those numbers and see how they behave and interact as you change settings and shooting modes. The nice thing with a DSLR is you can see the effect immediately!

02-17-2022, 03:09 PM   #8
Pentaxian




Join Date: Sep 2020
Posts: 645
https://www.diyphotography.net/what-is-middle-grey-and-why-does-it-even-matter/

Your camera meter wants the average of what it's reading to be the middle 18% gray (see link above)
ed: the gray scale I'm referring to is in the middle.

using the EC function is how you lie to the camera (in auto exposure modes) to make that average hit at a different point, lighter or darker.
02-17-2022, 03:17 PM   #9
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 28,161
I use exposure compensation on all of my cameras. I frequently use Av mode as I shoot largely static subjects and need more dof control than shutter speed control - biasing results easily to match my desired exposure without changing to M mode.
02-17-2022, 03:34 PM   #10
Forum Member




Join Date: Nov 2021
Posts: 69
In digital cameras, the EV dial allows a nice live quick view of the scene while letting the other camera settings float.

I usually auto-bracket when in varying tough afternoon light, -1/+1
02-17-2022, 09:34 PM   #11
Otis Memorial Pentaxian
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 42,007
QuoteOriginally posted by bertwert Quote
It's effectively setting the new 0 on the exposure meter.
This ^ ^ ^

I don't think I could have explained it better.


Steve
02-17-2022, 10:08 PM   #12
Pentaxian
swanlefitte's Avatar

Join Date: May 2015
Location: Minneapolis
Photos: Gallery
Posts: 4,068
QuoteOriginally posted by To_Omek Quote

. And now I'm so confused

When I'm in TAv mode and I change Exposure Compensation for minus or for plus, I can see that it changes aperture or shutter speed or those both values.
I believe that is your confusion. Are you sure about that? It only changes ISO for me and only within the set range.
02-18-2022, 01:27 AM   #13
New Member




Join Date: Feb 2022
Posts: 4
Original Poster
Thank you very much for such a warm welcome. Thank you for all your answers. Each of them brings some more light on the subject.

I’m aware of exposure triangle, I understand the concept of 18% grey and how the camera sees the world by its sensor. I catch how values in my view finder change and I get how to set them to get my desired results. Well, more or less, but it’s been three weeks with DSLR. I'm still doing my homework, reading a lot and experimenting with my Pentax.

I've just read your answers and brought my camera to check your ideas. I think I get it now

QuoteOriginally posted by bertwert Quote
It's effectively setting the new 0 on the exposure meter.
Thank you for the simpliest and the most accurate explanation. So now, I understand EC like this: I want to take a photo. I set desired mode in the camera. I find the perfect composition. I set values of shutter speed or aperture as I need for taking the photo. I shoot first photo. If it's too bright -> EC for - / if it's too dark -> EC for +. Then I have my reference point on how I want my balance of low, middle and high tones to be like. And now when exposure is set as I want, I can manipulate with depth of field or freezing movement etc. as I want. And my camera has its reference point of exposure. "The new 0". I told the camera "Hey, I want exposure that way, I don't care about your perfect grey. Here's my perfect grey and you better stick to it.".

On the other hand, when I take the photo and exposure is good for me. Then I don't need to adjust it, do I? I do it only when the output is too dark or too bright?

QuoteOriginally posted by swanlefitte Quote
I believe that is your confusion. Are you sure about that? It only changes ISO for me and only within the set range.
Yes, you're right. I checked it second time. I must've got wrong. It surely changes only ISO.

One more thing. I checked how EC works in M mode. Generally, in M mode I can see EC line in viewfinder. It indicates over or under exposure. I set aperture, shutter speed, ISO to reach the middle point "0" on that line. Right? Then If I want to, let's say overexpose by +2, I hit the EC button and dial +2. From now, the camera knows that I want brighter picture. I still need to reach "0" on the EC line in viewfinder. But when I reach "0" the photo would be brighter than before I changed exposure by 2 steps. Am I right?
02-18-2022, 02:43 AM - 1 Like   #14
Loyal Site Supporter
Loyal Site Supporter




Join Date: Jan 2013
Location: København, Danmark
Posts: 151
Welcome to the forum!
I usually underexpose by 2/3th to one stop on all my cameras in order to avoid blowing the highlights. You can always correct this in postprocessing if needed. The exception is the K3iii. Using multi-segment white balance and higlight-weighted metering, it is almost ridiculously easy to get a correctly exposed image.
02-18-2022, 04:51 AM   #15
Moderator
Loyal Site Supporter
Loyal Site Supporter
pschlute's Avatar

Join Date: Mar 2007
Location: Surrey, UK
Photos: Gallery
Posts: 8,109
QuoteOriginally posted by To_Omek Quote
On the other hand, when I take the photo and exposure is good for me. Then I don't need to adjust it, do I? I do it only when the output is too dark or too bright?
Correct.

QuoteOriginally posted by To_Omek Quote
I still need to reach "0" on the EC line in viewfinder. But when I reach "0" the photo would be brighter than before I changed exposure by 2 steps. Am I right?
Correct.

QuoteOriginally posted by To_Omek Quote
I told the camera "Hey, I want exposure that way, I don't care about your perfect grey. Here's my perfect grey and you better stick to it.".
In your camera menu there is a Memory Settings item. You can select which settings you want to maintain when the camera is switched off. EC is one of the options. I generally set the camera so that EC is not remembered on camera switch off, but you may wish to change this. Alternatively you can set this to a USER mode.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
aperture, change, changes, compensation, exposure, exposure compensation, feature, k-70, k70, mode, pentax k-70, shutter, tav
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Exposure compensation usage leodp Pentax K-1 & K-1 II 30 07-14-2021 12:09 AM
MZ-S Adhesive to Re-attach Exposure Compensation Dial dms Troubleshooting and Beginner Help 2 01-03-2021 02:18 PM
Flash Compensation, Overall Compensation and Ambient Lights Rashedul Flashes, Lighting, and Studio 3 01-11-2013 04:19 PM
Long exposure / provia 200 : how to know the good exposure compensation ? aurele Film SLRs and Compact Film Cameras 3 02-18-2012 06:58 PM
Camera exposure compensation vs flash compensation raider Photographic Technique 4 09-29-2011 05:02 PM



All times are GMT -7. The time now is 02:49 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top