Good filter for keeping skies from being over exposed?

inTempus · Jan 9, 2009

I've noticed that I'm getting a lot of over exposure from the bight (non-cloudy) skies in my city shots lately. I've been trying to get some shots of the skyscrapers in downtown Chicago but it always seems no matter how hard I try I get blown out skies.

I assume I need a filter. If so, what filter do I need?

Chris of Arabia · Jan 9, 2009

Try a graduated Neutral Density filter - easily obtainable and are designed to do exactly the job you describe.

Big Mike · Jan 9, 2009

Yes, typically you would use a split or graduated ND filter. The problem is that these filters have a straight line transition from light to dark...and if you are shooting a skyline type image, the filter might darken other parts of the image, besides the sky.

Having blown out skies is often a result when the difference between the fore/mid-ground and the sky is too great for a camera to capture with one exposure. Usually it's up to the photographer to decide what parts of the image are most important and expose for that.

There are a few tricks you can do though.
You could selectively edit the image (mask of parts of it to edit the other parts).
You could take two different exposures and combine them.
You could take multiple exposures and use software for tone mapping or HDR etc.

Samanax · Jan 9, 2009

Cokin Standard And Pro Holders

Cokin Graduated Filters

inTempus · Jan 9, 2009

Thanks guys.

So, about HDR... does anyone know of a good application for doing HDR on a Mac?

I have regular tools already (CS3, Lightroom 2, Aperture 2)... I assume there's some specialized application(s) for HDR work.

Big Mike · Jan 9, 2009

HDR photo software & plugin - Tone Mapping, Exposure Blending & HDR Imaging for photography

Judge Sharpe · Jan 9, 2009

If you will excuse advise from an old time film guy, you need to play with your exposure in a manual exposure mode. What is happening is that your in camera exposure meter is taking a reading from the general area and is averaging the reading. Most likely, it is too much for sky and too little for the building.
So here's what I would do-
1. See if you have a spot meter function on your camera.
2. If not- see if you can take discrete readings from the sky and the subject. Decide which will give you what you want; or.
3. If this is your field of endeavor, invest in a spot meter about $100.00;or,
4. Take a reading from an 18% gray card and use that as a starting point. The exposure where you are will be about what it is on your subject unless you are in a shadow;or,
5. Bracket your shots- One at the exposure suggested by the camera, 3 at shorter exposures separated by 1/2 to 1 stop and the same thing on the other side. Film is cheap so waste a little to get the shot you want.
6. Think about adjusting exposure/contrast with selective printing.
7. A polarizing filter does wonders for darkening the sky as it cuts the light scatter that causes glare. It does wonders for a cloud picture.
Good luch and good shooting
Judge Sharpe

elemental · Jan 9, 2009

Circular polarizers can be used for this purpose, though they can be a little finicky, especially when you can't change your angle to the sun. It will work in some situations though, and will also be handy for cutting glare on glass windows. It will also cost you some light (probably 2 stops), so plan accordingly.

It's not a cure-all, but in a shot that happens to line up the right way it could wotk wonders.

inTempus · Jan 9, 2009

Judge Sharpe said:
If you will excuse advise from an old time film guy, you need to play with your exposure in a manual exposure mode. What is happening is that your in camera exposure meter is taking a reading from the general area and is averaging the reading. Most likely, it is too much for sky and too little for the building.

I have a Canon 40D and I do have spot metering. I was trying all metering modes with varying levels of success, but still getting blown out skies downtown. I think it was because shooting up at tall buildings while in their shadows towards a bright blue sky is probably more than a camera can compensate for. I make this assessment based upon me trying multiple different methods (in manual mode and P mode) and still getting either too dark of an exposure on the building or a blown out sky.

I'll give the HDR and bracketing a shot, and I will probably check out a filter if they are reasonably priced to see if that helps me get where I want to be.

inTempus · Jan 9, 2009

Big Mike said:
HDR photo software & plugin - Tone Mapping, Exposure Blending & HDR Imaging for photography

Sweet, I just downloaded it and look forward to playing with it this weekend.

NateWagner · Jan 9, 2009

yeah... well, I will say that with lightroom2 it is rather simple to bring in sky that is normally blown out in similar situations to that. The only problem you'll run into is if you have to work around trees and the like, but with a rather large expanse of sky it's really not too difficult.

Personally, I would think that PP would be the easiest method compared to a graduated ND or anything of that like. Multiple exposures could work well also.

elemental · Jan 9, 2009

NateWagner said:
Personally, I would think that PP would be the easiest method compared to a graduated ND or anything of that like. Multiple exposures could work well also.

Lightroom's graduated filters can be used as a completely customizable neutral density filter- you control where it starts, ends, the angle it's on, and the exposure compensation. As long as you have enough room in your file to do some pushing/pulling with things (it's never been a problem for me shooting RAW), you can really dial it in exactly the way you want it. Just don't blow your skies out completely- if there's nothing left, there's nothing to pull back.

Mgw189 · Jan 9, 2009

NateWagner said:
Personally, I would think that PP would be the easiest method compared to a graduated ND or anything of that like. Multiple exposures could work well also.

This is a statement I have a real hard time with. While yes PP should be a part of work flow to say its easier to fix with PP than taking a good picture with the right tools blows my mind. If you use the right tools and get a good photograph than any PP you are going to need to do is going to be much easier.

For the OP here is an image that I took with a Graduated ND filter. To be quite honest it is the best $30 I have spent and I bought it for the exact problem you are having. If you look right at the point where the mountains and the sky meet you can see the quality of the sky that I was working with. The only PP done to this photo is the smallest saturation boost and some unsharp mask.