Sky 'blow-out' advice

Chonga

Chonga

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Lee
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Please bare with me as I've still got the L-Plates on.
I took my new sigma 10-20 out yesterday for a few test shots in a Rape field. When I got home I found the sky in all the snaps had blown out badly.
The lens had on it a UV filter, it was early afternoon and the sun was about 90 degrees to the lens looking forward.
I would appreciate comments and advice as to where I went wrong and what I should do to prevent this happening again in the future. Cheers.

IMG_4704.jpg


ISO:100 , f/16 , 1/45 , AutoWB , f.length 18mm
 
Ive had the same issues and am working on it,in my old film days i would have used a grad filter but with digital i take a couple of exp one for the sky and one for the foreground and blend the two exp together in cs2 this works for a static object, if you can only grab the one shot you can work off one Raw saved at different exp and blend again is PS sorry if that is not what you are after but that is how i get around blown sky.

hth Michael.
 
Expose for the sky and see what that leaves you with in the foreground.
On a bright day, there shouldn't be too much of a loss.
You could set your preview screen to flash blown highlights, its just a quick glance without checking histograms.
 
With the sun direction you describe a polariser would probably be enough to hold back the sky. Downside with wide angle is that the darkening may not be even across the sky.

Other option is ND grad filters like the cokin one below (on the right). You slide the filter up and down to get the edge on the horizon.

filters.jpg


You can do it with multiple exposures and software but it seems much easier/better to me to get it right in camera.
 
I agree Robert but not fully i feel if you have to put a filter in the light path nothing wrong with that by the way you or me are compensating for the fact we can't get it right in camera so need a little help, to me filters/software are all tools to help the camera out i used to carry loads of filters for film i just think sw is less to carry in the field i am either getting old or lazy both i think.

Michael.
 
Think it depends on personal preferences. I don't enjoy photoshop type activities. I also don't often travel with a tripod so aligning 2 images for editing together just adds to the complexity.

Truth is I rarely use the ND grads as a polariser usually does all the sky darkening I need.
 
I'm with you on this one Robert. I recently invested in some filters for exactly that reason. You can't drop a grad in photoshop as well as (I think) you lose some definition in the sky. Just my personal preference. It does make metering a whole lot easier with the filter and I find it a lot easier to "balance" the foreground and background.

One example where I used a grey grad to hold the sky a little.
2365042068_24ca3c299e.jpg
 
Thank you for your comments. I think I'm grasping what you are all saying. More cash needs be spent basically.:D
Somebody warned me when I bought my DSLR that it was a rewarding but a KERCHING! hobby.
I suppose another alternative is to take the picture at a different time in the day when the sun's light is not quite so fierce. (and I don't mean at night.;))
 
To start with i would go with Joxby's idea and try exposing for the sky to see where that gets you, failing that filters. I am totally with Robert on reducing the time in front of the PC.
 
Robert

If you have CS3 you have the " Auto Align Layers" which will help you if you don't have a tripod.
 
Chonga, a few suggestions....

1. Shoot in raw and not jpeg. That will give you some potential to recover blown highlights and boost shadow detail. The raw image file will contain a lot more data than any jpeg out of the camera and this will allow you to fine tune levels/curves/exposure with little loss of quality. Jpegs simply don't permit the same levels of adjustment in post processing.

2. Check your histogram - preferably RGB - and also look for blinking warnings of blown highlights in the thumbnail image. Do not try to judge the success or otherwise of your exposure from the appearance of the image itself - just look for the blinking warning.

3. Bracket your exposures. If you're shooting in an autoexposure mode then you could use AEB or just manually dial in a little +/- exposure compensation. If shooting manually you can just as easily bracket by tweaking shutter speed.

4. Try a different metering approach - instead of metering the whole scene, use spot metering, if you have it, or partial metering, if you don't, and meter off the brightest part of the picture. Set your exposure compensation to +2. That should comfortably hold the detail in the highlights and let the rest of the image fall where it may. If you shoot with manual exposure you will probably find you an go even higher than +2, maybe even +3 stops over the metered value. You need to establish the threshold for your camera. With my 40D I can go 3 1/3 stops above my metered highlights before blowing any of the RGB channels.

5. Your picture looks a little overexposed to me, and I'm not talking about the sky. I see you dialed in a little +ve EC, and I'm not sure you needed to do that.

6. Did you turn your CPL to get maximum effect? The colours in the plants do not look very saturated (partly to do with overexposure, I think) and I would expect richer colours if the CPL was doing its job.

EDIT : Re point 5, the plants are not overexposed - they are perfectly exposed to the right - but that does, of course, leave no room at all for the sky. I think cancelling the +0.5 EC and shooting raw would surely have helped here, but probably not quite enough to completely hold the sky.
 
tdodd said:
4. Try a different meterig approach - instead of metering the whole scene, use spot metering, if you have it, or partial metering, if you don't, and meter off the brightest part of the picture. Set your exposure compensation to +2. That should comfortably hold the detail in the highlights and let the rest of the image fall where it may. If you shoot with manual exposure you will probably find you an go even higher than +2, maybe even +3 stops over the metered value. You need to establish the threshold for your camera. With my 40D I can go 3 1/3 stops above my metered highlights before blowing any of the RGB channels.
Click to expand...

If he is in aperture priority or shutter priority and follows the lead to add +2 in exposure compensation... he will get even BRIGHTER sky.
He needs to dial in MINUS exposure compensation in this setup to darken the shot.
Now if he is shooting manual... then +2 etc will work and make the spot metered bright spots correctly exposed.

Well that has always been MY understanding anyway!! :)
 
Janice said:
If he is in aperture priority or shutter priority and follows the lead to add +2 in exposure compensation... he will get even BRIGHTER sky.
He needs to dial in MINUS exposure compensation in this setup to darken the shot.
Now if he is shooting manual... then +2 etc will work and make the spot metered bright spots correctly exposed.

Well that has always been MY understanding anyway!! :)
Click to expand...

No! If he SPOT/PARTIAL meters off the BRIGHTEST part of the picture (the brightest cloud in the sky) there will be nothing brighter than that area. Now he doesn't want the BRIGHTEST part of the image to be captured as "middle grey" - he wants it to be captured at the top end of his sensor's capability to record light without blowing anything.

The camera should comfortably have a dynamic range of around 3 stops above middle grey. So if he meters the brightest part and add 2-3 stops he should perfectly capture the highlights without blowing anything.

Whether he's shooting in manual or auto mode doesn't really matter, except he can't dial in more than +2 stops EC in auto exposure mode. In manual mode he can just keep clicking 9 clicks to the left to add three stops of +EC (assuming he has 1/3 stop increments on his dial). He may even find he can go to +10 or +11 clicks without blowing anything, although I suspect +9 will be about right. The exact amount depends on his camera body, how accurately he can determine the brightest part of the sky, and how precisely he can pinpoint the metering to the brightest point (spot vs partial).

For the avoidance of doubt, although it's obvious to me, if he uses autoexposure and spot/partial meters off the sky, he will, of course, have to lock exposure before recomposing the scene. Personally I'd go for manual exposure for the extra control it offers, and that would lock the exposure, wherever he points the camera.
 
tdodd said:
Chonga, a few suggestions....

1. Shoot in raw and not jpeg. That will give you some potential to recover blown highlights and boost shadow detail. The raw image file will contain a lot more data than any jpeg out of the camera and this will allow you to fine tune levels/curves/exposure with little loss of quality. Jpegs simply don't permit the same levels of adjustment in post processing.

2. Check your histogram - preferably RGB - and also look for blinking warnings of blown highlights in the thumbnail image. Do not try to judge the success or otherwise of your exposure from the appearance of the image itself - just look for the blinking warning.

3. Bracket your exposures. If you're shooting in an autoexposure mode then you could use AEB or just manually dial in a little +/- exposure compensation. If shooting manually you can just as easily bracket by tweaking shutter speed.

4. Try a different metering approach - instead of metering the whole scene, use spot metering, if you have it, or partial metering, if you don't, and meter off the brightest part of the picture. Set your exposure compensation to +2. That should comfortably hold the detail in the highlights and let the rest of the image fall where it may. If you shoot with manual exposure you will probably find you an go even higher than +2, maybe even +3 stops over the metered value. You need to establish the threshold for your camera. With my 40D I can go 3 1/3 stops above my metered highlights before blowing any of the RGB channels.

5. Your picture looks a little overexposed to me, and I'm not talking about the sky. I see you dialed in a little +ve EC, and I'm not sure you needed to do that.

6. Did you turn your CPL to get maximum effect? The colours in the plants do not look very saturated (partly to do with overexposure, I think) and I would expect richer colours if the CPL was doing its job.
Click to expand...

Thanks Tdodd. That's a lot of information for me to get my head around.

1. Note taken about RAW and will do in future.

2. I may sound a bit silly but when I look at a histogram it's all a bit baffling to me. What sort of thing am I meant to be looking for in the graph? Also, I've had a quick flick through the manual and it doesn't look like the 10D has the blinking facility in the thumbnails (but I could easily have missed it though)

3. I'll give AEB a go as well.

4. Again a bit scarey. I have partial metering so will give that a bash. When you say 'metering off' do you mean use my AE lock (* icon) on the brightest part (sky) and then recompose the picture?

5. Will look at that a try to reset it to the centre mark. Not sure how I managed to set it to +0.5 in the first place to be honest.:thinking: Bought the camera secondhand so may have been set by previous owner.

6. Didn't have a CPL on the lens which I appreciate would have made difference to the colour. It's a new lens and the money I was saving to buy a CPL got spent on a FA Cup Semi Final ticket.

I'm going to print this info off and take it with me when I revisit the same spot for second try this coming weekend. Cheers.
 
1. Good stuff :)

2. The histogram shows the distribution of light and dark tones throughout the image and gives an indication of how much of each you have. If the histogram is all bunched up at the right hand side then your shot is overexposed. It is a good thing for it to touch the right hand edge but if there is a big spike on the extreme edge, that means you've overexposed a lot of pixels. There are lots of guides to histograms on the net. A Google will find plenty. Here's one good example....

http://www.cambridgeincolour.com/tutorials/histograms1.htm

About half way down the page there are sample pictures and their respective histograms, indicating what clipped highlights look like in an overexposed image.

I don't know whether the 10D has the blinking warning or not. On the 30D and 40D I think you have to enable the feature - it is not enabled by default. EDIT : Yes it does. See this page - http://www.dpreview.com/reviews/CanonEOS10D/page9.asp.

3. With a bit more experience, this is a fairly easy scene to meter and expose correctly - especially if you use your histogram to check your exposure. For difficult scenes, or if you're not sure what you're doing, at least AEB will enable you to go home with the shot in the bag. Your approach depends on what is more important - getting the shot, or learning how to get the shot. AEB can also be a handy way to try to learn more about how your camera's metering works, and maybe why "the meter got it wrong".

4. That's it exactly :) But it's my guess +2 EC will not be enough. You'll ideally need to switch to manual exposure so that you can force more than 2 stops brighter than the metered reading.

5. I don't know the 10D - I have a 30D and 40D. The manual should tell you all. EDIT : OK, I just checked the DPReview website to look for an example of the blinking highlight warning, and saw an image of the back of the 10D. There is a thumbwheel on the back, the same as the 30D and 40D. The power switch has two "On" positions. If you turn the camera "On" to the second "On" position - i.e. all the way "On" - this will enable the thumbwheel to function. In an AE mode, half press the shutter, so that the camera becomes operational, and then rotate the thumbwheel while looking through the viewfinder. You should see the meter needle moving back and forth. The thumbwheel is controlling your exposure compensation. Centre the needle and then set the "On" switch back to the first "On" position. That will prevent the thumbwheel operating and thus prevent any accidental adjustments to EC.

If you do want to change your EC again then turn the power switch to the second "On" position to re-enable the thumbwheel and make your adjustment.

6. Sorry, my mistake, I saw UV filter, and your comment about the angle of the sun, and my mind just invented CPL instead of UV. When you shoot with a CPL filter, and the sun at 90 degrees, you can twist the filter to darken skies and get deep, rich, saturated colours in plant life (and other things). A CPL would probably have done you a favour for this shot, although normally it is effective at darkening blue skies. I'm not sure it would do so well for clouds, but it should enrich the greens and yellows in the plants.
 
Thanks again . Valuable stuff all round. :thumbs:
 
Most landscape photographers use ND grads to balance the exposure between ground/sky.

It's a whole lot easier than trying to achieve it in PS or different exposures at the scene.

Cokin do a good all round set-cheap and cheerful-but do the job-and you can get different sized adapters for different lenses.
 
Well the other choice would be to choose a different time of day or different weather conditions. Personally I'd prefer a clear blue sky with a few fluffy white clouds. Sometimes you just have to go with what nature or opportunity presents at the time.
 
I've just done a very quick post on my blog about balancing the sky (very basic) but I did a quick comparison with and without grads just for those who are thinking about getting some, here is the before and after, they really make a difference and so much easier than messing with CS3 in post, these were both taken at ISO100, f16 1/60 16mm

IMG_0883-751409.jpg


IMG_0882-737559.jpg
 
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