Technical Help : Is this backlight correction?


Dec 12, 2012
871
9
0
Singapore
#1
Hi all CS users.

I went out street shooting yesterday with my new Tammy 24-70. Was having fun. But came across a problem that I thought you guys would be able to address.

Equipment :
-Canon EOS 650D
-Tamron 24-70 VC Di USM SP
-Kenko Zeta Protection Filter
-Kopi Gao Siu Tai.
As I was shooting in the late afternoon, 4pm thereabouts, I think the light was quite harsh at most times.

I snapped this scene. I was unhappy with the quality because the foreground was much brighter than the background.
I tried all 4 metering modes and all produced very similar output. Changed exposure levels as well, but no improvement.

Original (too dark) by Norman Selvaraju, on Flickr



It was only after I got home, read up online that I understood that it required backlight (in this case front light?) correction.
And I adjusted the Blacks/Exposure/Contrast/Shadow/Highlight of the RAW image to get this which was slightly better.

Ah.. Much Nicer now by Norman Selvaraju, on Flickr


Question :
-Am I on the right track? I mean, did I identify the problem correctly?
-The various articles I read: eg -- Link to article, generally suggest working on adjusting Shadows/Highlights on the image file and not the RAW file. But wouldn't it be better to work on the RAW file instead?
-Is there a way to correct it while taking the shot? Cos my eyes see it the way I wanna capture it. But I can't seem to get the camera to do so. Any suggestions? What metering mode should be used?

Thank you.
Btw, Link to the rest of the photos for that shoot on Flikr. C&C welcome.
Golden Hoard | Flickr - Photo Sharing!

Have a great weekend, all.
 

Last edited:

tecnica

Senior Member
Dec 26, 2004
3,660
10
0
#2
from the EXIF, you were using centre-weighted metering which was why you got those over exposed surroundings, because the camera had given priority to whatever was in the centre of the frame(hence centre-weighted). the middle of the frame was filled with blacks and to expose for this, the camera would need a longer shutter speed which will cause the surrounding to be slightly over exposed.

you said that you tried all 4 metering modes and it was all the same. in this case, you could have dialed in some negative exposure compensation(to underexpose the image) to get the image to where you wanted it to be. apart from this, since you were shooting in RAW and within dynamic range, you can bring back the over exposed areas by recovering the highlights in post.

the camera is only as smart as the user. a lot of time, you have to evaluate the scene yourself and adapt the settings accordingly. :)
 

Last edited:
Dec 12, 2012
871
9
0
Singapore
#3
tecnica >>> Thanks! Ok.. so in this case, since I am on centre-weighted metering mode, I should have set a negative exposure compensation to reduce the overexposed forground. But wouldn't that make the centre darker as well?
 

tecnica

Senior Member
Dec 26, 2004
3,660
10
0
#4
tecnica >>> Thanks! Ok.. so in this case, since I am on centre-weighted metering mode, I should have set a negative exposure compensation to reduce the overexposed forground. But wouldn't that make the centre darker as well?
yes, it will make the centre darker a bit.

it depends on what you are comfortable with, recovery highlights or bumping shadows in post.

for canon dslr, i recommend over exposing the photo(to reveal the blacks) a little as the current sensors are still relatively weak in bumping shadows. recovering highlights in post will be the better choice.
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#5
Hi all CR users.

I went out street shooting yesterday with my new Tammy 24-70. Was having fun. But came across a problem that I thought you guys would be able to address.

Equipment :
-Canon EOS 650D
-Tamron 24-70 VC Di USM SP
-Kenko Zeta Protection Filter
-Kopi Gao Siu Tai.
As I was shooting in the late afternoon, 4pm thereabouts, I think the light was quite harsh at most times.

I snapped this scene. I was unhappy with the quality because the foreground was much brighter than the background.
I tried all 4 metering modes and all produced very similar output. Changed exposure levels as well, but no improvement.

Original (too dark) by Norman Selvaraju, on Flickr



It was only after I got home, read up online that I understood that it required backlight (in this case front light?) correction.
And I adjusted the Blacks/Exposure/Contrast/Shadow/Highlight of the RAW image to get this which was slightly better.

Ah.. Much Nicer now by Norman Selvaraju, on Flickr


Question :
-Am I on the right track? I mean, did I identify the problem correctly?
-The various articles I read: eg -- Link to article, generally suggest working on adjusting Shadows/Highlights on the image file and not the RAW file. But wouldn't it be better to work on the RAW file instead?
-Is there a way to correct it while taking the shot? Cos my eyes see it the way I wanna capture it. But I can't seem to get the camera to do so. Any suggestions? What metering mode should be used?

Thank you.
Btw, Link to the rest of the photos for that shoot on Flikr. C&C welcome.
Golden Hoard | Flickr - Photo Sharing!

Have a great weekend, all.
All in all, I would say that the Kenko Zeta Protection Filter has done a good job to protect the Tamron 24-70 VC Di USM SP and the vibration control of the Tamron 24-70 VC Di USM SP has done a good job to counteract against the jittery effect that Kopi Gao Siu Tai often does to shooter's hands. Finally, Kopi Gao Siu Tai had done a good job in simulating the shooter's mind.

You are on the right track and has done well overall. Photography is always a compromise of physics, gain an f-stop of speed, loss an f-stop of depth, gain an f-stop of shadows, loss an f-stop of highlights. The dynamic range an JPEG file can show straight out of the camera is limited. RAW has captured more info and you have done a good job to bring that out in post process.

The next step of improvement you can do is to know much many stops of light more you can shoot to gain more indoors shadow data, before blowing out the outdoors highlight details of the walls, so as to maximize the file.

Finally, a little improvement you can now do to the current picture is to reintroduce some more contrast to make the picture more natural looking.
 

catchlights

Moderator
Staff member
Sep 27, 2004
21,903
46
48
Punggol, Singapore
www.foto-u.com
#6
whatever metering mode you use, it only tell how the camera how to expose the shots,
it does not alter the lighting of the scene,

in case you have no idea at all, for this scene, the exposure level of the light outside and inside is maybe three to four stops different,

either you;

- wait for the light of both inside and outside much closer, eg, shoot in the evening,
- set up additional lighting inside
- pulling highlight details and pushing shadow details extremely with Lightroom Room or photoshop
- Shoot HDR shoot in camera or by process at the post
- make two frames, one exposed for outside, one exposed for inside, do a layer merge in photoshop



hope this help.
 

Dec 12, 2012
871
9
0
Singapore
#7
yes, it will make the centre darker a bit.

it depends on what you are comfortable with, recovery highlights or bumping shadows in post.

for canon dslr, i recommend over exposing the photo(to reveal the blacks) a little as the current sensors are still relatively weak in bumping shadows. recovering highlights in post will be the better choice.
tecnica >>> Thanks for the tip. I'll keep that in mind when I take the next shot in similar circumstances. Thanks again!
 

Dec 12, 2012
871
9
0
Singapore
#8
sjackal >> Haha.. I'm glad you approve of my equipment! Thanks for pointing me toward what I need to develop further! Yeah, I'm still working on figuring out how to correctly assess the scene and truly represent it through my camera. Understanding and evaluating the difference in full stops of light is gonna take quite a lot more of experience I foresee!!

And yeah, I'll add in working with contrast too. I have not yet truly perfected my workflow for post processing. Shall keep trying and see what works best!

Thanks for your comments and advice!
 

Dec 12, 2012
871
9
0
Singapore
#9
catchlights >>>

Wow. Thanks for breaking it down for me like that. It all makes better sense now! I actually had a couple more photos where i experienced the similar issues. Now I know what I can do to address the problem should it occur again.
 

Dec 12, 2012
871
9
0
Singapore
#10
To all the CS members in general.

I just wanna shout out a thanks in general for all the experienced photographers who take the time and effort to sop by and address the concerns of the newbies like me. It is really encouraging to know that should I (or other newbies for that matter) face a stumbling block, we can turn to the experience of the CS Forumers for some guidance. Really appreciate it!

And to those who replied to this thread, I appreciate the advice! Thanks for helping me see the light! (Haha.. Pun intended)

Cheers all..
 

Shizuma

Senior Member
Mar 19, 2012
2,557
25
0
#11
catchlights >>>

Wow. Thanks for breaking it down for me like that. It all makes better sense now! I actually had a couple more photos where i experienced the similar issues. Now I know what I can do to address the problem should it occur again.
remember to use a tripod or your next shot will not be exactly identical in terms of framing. use a remote or 2-second timer to trigger for max precision. also if you are shooting with camera/tripod on the road please beware of traffic. A vehicle hitting your tripod or yourself will result in severely off framing, among other things. :)
 

tecnica

Senior Member
Dec 26, 2004
3,660
10
0
#12
no worries, sharing is caring.
 

zaren

Moderator
Staff member
Oct 27, 2003
10,961
29
48
#13
you are on the right track, and good points made by catchlights.
HDR or further backlight correction may help to balance better the exposure of this image.
 

thoongeng

Senior Member
Jan 26, 2010
1,260
19
38
#14
Question :
-Am I on the right track? I mean, did I identify the problem correctly?
-The various articles I read: eg -- Link to article, generally suggest working on adjusting Shadows/Highlights on the image file and not the RAW file. But wouldn't it be better to work on the RAW file instead?
-Is there a way to correct it while taking the shot? Cos my eyes see it the way I wanna capture it. But I can't seem to get the camera to do so. Any suggestions? What metering mode should be used?
agree with the experts above
remember your eyes can see much more dynamic range (difference between the lightest and darkest areas in a frame) than your camera. So the resulting photo captured may not be what you saw or think you saw (hmm... so much for 'cameras don't lie'... they also can't speak the whole truth ;p)

Regarding your question on the article that says 'adjusting Shadows/Highlights on the image file', it refers to the tool being used. When you are using the 'Blacks/Exposure/Contrast etc' sliders, you are probably working in Lightroom or Adobe RAW, while 'Shadows/Highlights' is an adjustment in Photoshop. Both tools can help to achieve the above, just that in Photoshop itself you can't work on a RAW file directly that's why it says work on 'image file' (Photoshop uses Adobe RAW to 'develop' the RAW file first before it can work on it)

Hmm sounds confusing but hope this helps :)
 

Dec 12, 2012
871
9
0
Singapore
#15
Shizuma>> haha. Nice one. I shall etch out for traffic. And yes, as interesting as the framing would be were a car to hit my tripod, I think I shall avoid it. Hahah.

Zaren>> thanks for sharing your version of the post processing. I've seen several of your post processed pics on different threads. Very nice, I must say. I shall keep a look out for more!
 

Dec 12, 2012
871
9
0
Singapore
#16
Thoongeng>> thanks for the clarification. My question arose because I understand that working on the Raw image (I use PS cs4 DNG Convertor Camera Raw 5.7) for post processing would produce better results.

But according to the guides I read, they use photoshop's shadow/highlight tool which has many many more tools in the sub menu like tones and radius etc in that menu for specific calibration.

Whereas, when working on the RAW files, I only see two sliders shadows and highlights without the rest of the nifty looking options. So I was a little confused as to why that is so.

After reading your reply, I understand two things:
1) I should work with the raw file cos it contains more information
2) the shadow and highlights sliders aren't the only sliders that can be used to correct backlight. Hence I am not "losing out" by processing the raw image instead of the jpg image.

Thanks again for leading my doubts!
 

Last edited:

nulbonklr

New Member
Dec 1, 2007
267
0
0
www.facebook.com
#17
Hi all CS users.

I went out street shooting yesterday with my new Tammy 24-70. Was having fun. But came across a problem that I thought you guys would be able to address.

Equipment :
-Canon EOS 650D
-Tamron 24-70 VC Di USM SP
-Kenko Zeta Protection Filter
-Kopi Gao Siu Tai.
As I was shooting in the late afternoon, 4pm thereabouts, I think the light was quite harsh at most times.

I snapped this scene. I was unhappy with the quality because the foreground was much brighter than the background.
I tried all 4 metering modes and all produced very similar output. Changed exposure levels as well, but no improvement.

Original (too dark) by Norman Selvaraju, on Flickr



It was only after I got home, read up online that I understood that it required backlight (in this case front light?) correction.
And I adjusted the Blacks/Exposure/Contrast/Shadow/Highlight of the RAW image to get this which was slightly better.

Ah.. Much Nicer now by Norman Selvaraju, on Flickr


Question :
-Am I on the right track? I mean, did I identify the problem correctly?
-The various articles I read: eg -- Link to article, generally suggest working on adjusting Shadows/Highlights on the image file and not the RAW file. But wouldn't it be better to work on the RAW file instead?
-Is there a way to correct it while taking the shot? Cos my eyes see it the way I wanna capture it. But I can't seem to get the camera to do so. Any suggestions? What metering mode should be used?

Thank you.
Btw, Link to the rest of the photos for that shoot on Flikr. C&C welcome.
Golden Hoard | Flickr - Photo Sharing!

Have a great weekend, all.
Good try.. If you have the time to setup with tripod, take a few similar shots with different exposures, merge them in HDR. Should looks great.
 

thoongeng

Senior Member
Jan 26, 2010
1,260
19
38
#18
Thoongeng>> thanks for the clarification. My question arose because I understand that working on the Raw image (I use PS cs4 DNG Convertor Camera Raw 5.7) for post processing would produce better results.

But according to the guides I read, they use photoshop's shadow/highlight tool which has many many more tools in the sub menu like tones and radius etc in that menu for specific calibration.

Whereas, when working on the RAW files, I only see two sliders shadows and highlights without the rest of the nifty looking options. So I was a little confused as to why that is so.

After reading your reply, I understand two things:
1) I should work with the raw file cos it contains more information
2) the shadow and highlights sliders aren't the only sliders that can be used to correct backlight. Hence I am not "losing out" by processing the raw image instead of the jpg image.

Thanks again for leading my doubts!
Hmm I think you are a bit confused by how photoshop handles the files...
When you open a RAW file in Photoshop, it opens in Adobe Camera RAW first, that's why you only see the 2 sliders of shadows and highlights. If you don't do anything and click 'Open', the resulting image (with the defaults applied) will then open up in Photoshop. Now you can go to the menu to choose the shadow/highlight tool to work on the image.

The difference in working in the 2 programs, other than their features, are in how they save the changes. Adobe Camera RAW saves the changes as 'metadata', just a set of instructions what to adjust in the RAW file when opening it, without altering the RAW file. Photoshop also does not alter the RAW file, so you need to save as another file, and you can choose the format eg PSD/TIFF/JPG etc. This file includes all the image information.
 

Dec 12, 2012
871
9
0
Singapore
#19
Nulbonklr >> Thanks for the tip. Shall revisit this spot with my tripod, one day soon. I have never tried a HDR shot yet. I've only just begun to read up on it. Thank for the tip!

Thoongeng>>> Thank you very much. I really didn't know that's how it worked. I had the misconception that PS could only open and work on compressed files and not RAW files! Which is why I usually stopped my processing after working on the image with Camera RAW. Now that you have clarified that is not the case, I am quite excited that I have even more tools to work on with processing of the RAW files. BOTH Camera RAW 5.7 and PS CS4! Cool!

I wonder how long I would have carried on with this misconception had you not highlighted it. Thanks Thoongeng.
 

thoongeng

Senior Member
Jan 26, 2010
1,260
19
38
#20
Nulbonklr >> Thanks for the tip. Shall revisit this spot with my tripod, one day soon. I have never tried a HDR shot yet. I've only just begun to read up on it. Thank for the tip!

Thoongeng>>> Thank you very much. I really didn't know that's how it worked. I had the misconception that PS could only open and work on compressed files and not RAW files! Which is why I usually stopped my processing after working on the image with Camera RAW. Now that you have clarified that is not the case, I am quite excited that I have even more tools to work on with processing of the RAW files. BOTH Camera RAW 5.7 and PS CS4! Cool!

I wonder how long I would have carried on with this misconception had you not highlighted it. Thanks Thoongeng.
You're welcome :)
It also took me some time to wrap my head around it hehe
 

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