Matrix vs. Spot metering (blown highlights)

[Hlop]

Hi All,

Just would like to know what people think about subject? I'm aware about bracketing and image merging method but there are situation when it can't (shouldn't) be used. E.g. when you have a moving object in the frame.

The following image has been taking with spot metering and manual exposure. Exposure seems to be OK and image reflects what I saw that day but you can see a blown highlight at the top left corner.



If I'd use matrix metering and exposure compensation, I could get rid of highlight but alley and bicyclists will be darker. Bracketing isn't good for this type of shot. So, the question is what would you do in this situation? Leave blown highlights or darken the scene and have details of the sky? With the spot metering I'm getting precise exposure of the subject, with matrix I'm getting average exposure for the whole scene. What would you use?

[Aussie Dave]

very difficult situation. A huge catch 22 really.....

Not sure if I'd try using spot metering and expose for "middle-ranged area" near the blown sky and part of the trees in the top left corner, hopefully balancing out the blown highlights vs darker scene situation.

Because the dynamic range is so huge, the only likely option you have is to choose which part of the spectrum will work best and run with it. In this instance, maybe cropping the blown sky out will solve the problem, rather than having a nicely exposed patch of sky in the corner and a darkened scene ?!?

Certainly a tricky one....

Interested to see what others would do.

[Oneputt]

I think that this is a problem that we all strike when faced with a subject with a large range of light conditions. I don't know that there is an easy answer.

[Hlop]

Hi Dave,

In this particular shot crop might help but there are situations when you can't just crop blown highlight. Sometimes it may disbalance an image or sometimes it isn't possible at all. For example check second shot in this tread: http://www.d70users.net/viewtopic.php?p=74247

[the foto fanatic]

I think I'd crop out the highlight if it bothered me so much.

A line across the frame at the top of the lovely autumn-coloured tree wouldn't harm the pic at all.

However, I also think that having the lower part of the image slightly darker would be OK too.

[Hlop]

I think that this is a problem that we all strike when faced with a subject with a large range of light conditions. I don't know that there is an easy answer.

We aren't looking for easy ways here We're looking for solutions for complicated problems and that makes life interesting!

[Oneputt]

Hlop - all I try and do is expose until the highlights are under control. I then hope to fix things in PS.

[Aussie Dave]

Hi Dave,

In this particular shot crop might help but there are situations when you can't just crop blown highlight. Sometimes it may disbalance an image or sometimes it isn't possible at all. For example check second shot in this tread: http://www.d70users.net/viewtopic.php?p=74247

very true. I think the only thing one can do is decide which spectrum of the dynamic range will suit best and run with that. Sometimes there isn't much you can do about it and sometimes, with some PP work you can.

Not sure there is a definite answer to this problem....

[Hlop]

Oneput,

It's very easy to fix highlights but overall scene will be dark then and later on you can get very distractive noise in photoshop. I've tried this number of times and concluded that better give up some highlights and have proper exposure for main subject than heavily underexpose whole picture and especially subject

[Oneputt]

I know what you are saying and that is the approach that I think the CS2 Raw Converter takes on the auto setting.

[PiroStitch]

Crop a bit from the top portion to remove the overhanging leaves and PP the blown sky yourself using layers and layer masks in P/shop.

IMHO what you did is probably the easiest as it's easier to fix up a smaller patch of blown sky than it is to fix up the under-exposure of the cyclists due to the amount of other objects that you'd have to include in the fix up.

[stubbsy]

Mikhail

I'd do exactly what you've done here. If it's a tradeoff between blown highlights and noise I go with allowing blown highlights every time. In this image the blown highlights are an insignificant part of the scene and so don't distract from the image. I'd probably just clone them out.

[Deano]

I have two suggestions in addition to the idea of cropping (which I think would work here).

1. If you shoot raw then convert the image twice, one exposed for the sky and one for the subject. Then merge in Photoshop using the eraser and obacity (or a number of other techniques).

2. Select the sky in PS and replace with a patch of bluw sky from another shot.

Cheers
Dean

[Hlop]

1. If you shoot raw then convert the image twice, one exposed for the sky and one for the subject. Then merge in Photoshop using the eraser and obacity (or a number of other techniques).

2. Select the sky in PS and replace with a patch of bluw sky from another shot.

Hi Dean,

I'll start from the end

2. Would work in some situations but won't work for purists

1. Won't work because you're getting blown highlight initially in the RAW (we're talking about complicated light situation with very high dynamic range), when you exposed main subject properly

[Deano]

1. If you shoot raw then convert the image twice, one exposed for the sky and one for the subject. Then merge in Photoshop using the eraser and obacity (or a number of other techniques).

2. Select the sky in PS and replace with a patch of bluw sky from another shot.

Hi Dean,

I'll start from the end

2. Would work in some situations but won't work for purists

1. Won't work because you're getting blown highlight initially in the RAW (we're talking about complicated light situation with very high dynamic range), when you exposed main subject properly

1. I understand the dynamic range is the problem. My understanding is that ACR has the ability to resurrect highlights as long as the entire area isn't completely blown (ie 255, 255, 255). So if there is some texture there, ACR can do something with it. Worth a crack in any case.

Cheers
Dean

[Hlop]

1. I understand the dynamic range is the problem. My understanding is that ACR has the ability to resurrect highlights as long as the entire area isn't completely blown (ie 255, 255, 255). So if there is some texture there, ACR can do something with it. Worth a crack in any case.

Your understanding os source of the problem is correct. But the point of discussion is how people handle it in the cases when bracketing isn't solution. As you can see at sample shot, I preferred to expose alley correctly and gave up some highlights. Someone would shoot it with exposure compensation, not allowing highlight to blow, but get dark scene which needs to be corrected and most probably will be noisy.

In case of sample shot it was blown completely (255.255.255), so, ACR or NC won't help at all. Sky replacement only

[KerryPierce]

If I'd use matrix metering and exposure compensation, I could get rid of highlight but alley and bicyclists will be darker. Bracketing isn't good for this type of shot. So, the question is what would you do in this situation? Leave blown highlights or darken the scene and have details of the sky? With the spot metering I'm getting precise exposure of the subject, with matrix I'm getting average exposure for the whole scene. What would you use?

Depends on what you want out of the photo. For a single shot, I'd always do what you did. The subject is more important than blown highlights. I'd likely shoot it at -.3 to -.6EV, spot meter, for a single shot.

You can still bracket the scene, if your first exposure of the moving subject is correct and no other moving subjects will be crowding the scene afterward. Even with crowding of subject area, you can bracket for the sky area, which is real easy to do if you're on a tripod. The only real issues with bracketing the sky area is with wind blowing the leaves and clouds.

[gstark]

Mikhail

1. Won't work because you're getting blown highlight initially in the RAW (we're talking about complicated light situation with very high dynamic range), when you exposed main subject properly

Let's face it; there are often times where the contrast range of a subject exceeds the capabilities of the medium onto which you're shooting. This can happen in film as well as digital, and sometimes (and as Stubbsy so correctly says) you just have to accept that as a fact of life.

I certainly would have no issues accepting an image with a small section blown, as long as the rest of the image was expressing what I expected the image to express.

That said, pull your exposure back a little. Hopefully you'll get to a point where the blown section occupies only a minimal amount of the total image, and at the same time, your exposure will remain solid enough to give you a good working basis.

Create two identical images. The first one should based upon the (now correctly exposed) blown highlights. Yes, the other section will be dark.

Correct that darker section as the basis for your second image, and then merge the two together, masking as needed.

I will not accept any so-called "purist" arguments against this approach, because all that you're doing is the digital equivalent of dodging and burning that we would normally do in a traditional darkroom, and those practices have been around for ... longer than even I have!

IOW, all's fair in PP.

[Aussie Dave]

would a real "purist" use a digital camera ?

Whoops....that's opening a can of worms, isn't it ?!?

[Matt. K]

Mikhail
I tend to agree with Gary. There are some situations where you have to expose for the most important part of your subject and just accept a blown highlight. That has always been the case...even with film. In the image you have posted cropping would be ideal...but in many images you have to take what you can get. There is no solution.

[mickwhit]

Hi Hlop,

I'm willing to be corrected here, but I thought that you could eliminate the problem of blowing highlights by using Neutral Density filters or graduated ND filters.

Here are some examples of the various effects of filters (courtesy of B&H) that alleviate the problem of blowing highlights or in most cases the bright sky against a dark foreground.

http://www.pixspot.com/thumbnails.php?album=490

Some other sites of interest that you may wish to read are:

http://www.luminous-landscape.com/tutorials/digital-blending.shtml

http://forums.dpreview.com/forums/read.asp?forum=1034&message=11279330

Does anyone use ND or graduated filters to overcome the problem of blowing highlights?

Hope that helps.

Cheers,

Mick.

[gstark]

would a real "purist" use a digital camera ?

Whoops....that's opening a can of worms, isn't it ?!?

I don't see an issue here. Photography has always been a rather technical (and technological) process. I see the advent of digital phoptography as being just another step along that path

[digitor]

would a real "purist" use a digital camera ?

Whoops....that's opening a can of worms, isn't it ?!?

I don't see an issue here. Photography has always been a rather technical (and technological) process. I see the advent of digital phoptography as being just another step along that path

I tend to agree - otherwise, where would the line be drawn? Let's face it, the rot set in when lenses started being used - REAL photographers only use pinholes!

I guess you get my drift, shutters instead of lens caps, roll film instead of sheet, exposure meters, flash powder, bulbs, then electronic flash, and now even (gasp) cameras, lenses and flshes with computers inside them (and I'm only talking film cameras)

I could go on, in fact I often do, but on this occasion I will restrain myself...

Cheers

[Hlop]

Does anyone use ND or graduated filters to overcome the problem of blowing highlights?

Hope that helps.

Hi Mick,

ND won't help you in this situation at all. I'm using Cokin grad. ND but it's only good to get rid of blown highlights from the clouds in the bright sky as you described. Just imagine something bright next to your main object. What would you do then? You have to either expose main subject properly and let highlights to be blown or use exposure compensation to minimise blown area or completely fix it but it leads you to darkening the subject.

Matt and Gary just took my last hope away - there is no universal tablet wich helps in this condition

[Hlop]

Actually this was an interesting discussion. Thanks everyone who participated and anyone who just has red it through