What Type of Filter . . .

[Chip]

would be appropriate for this shot?

It was taken fairly early in the a.m., with the sun coming up to the right of the photo. I metered for what whas lit by the sun, so much of what's in the photo is in shadow and the sky is pretty much blown out.

I know I can lighten up the shadows using GIMP.

But if I wanted to get a better SOOC camera photo, what filter would be most appropriate? There's just a bit of fog/mist, and I don't know if a CPL would do away with that. Would a GND work?

I've never used a filter before, and would appreciate any advice.

Thanks!




Exposure: 0.008 sec (1/125)
Aperture: f/7.1
Focal Length: 6 mm
ISO Speed: 100
Exposure Bias: -33/100 EV
Flash: Flash did not fire

[PhotoNewt]

Two filters would be helpful here and can be used in combination.

With the sun coming up on your right side a polarizer filter can increase color saturation and contrast especially on the blues and greens.

To decrease the exposure difference between the bright sky and the ground a graduated neutral density (GND) filter is very appropriate to bring as much of the scene as possible into adequate exposure. You mount the glass filter on a holder and orient the dark portion to cover the sky and align the middle line with the horizon.

Use your camera meter system (use spot or partial meter function if available) to find the difference in exposure between sky and ground: set the aperture to say f/11 and point the camera at the sky (careful to avoid the sun) and take a reading, say suggested shutter speed is 1/500. Then point the camera to the ground and measure the exposure, say it reads 1/60. There is a difference of 3 stops between the sky and ground: 1/500 -> 1/250 -> 1/125 -> 1/60. With that information select the appropriate filter to reduce the exposure difference (I would use a 1-stop combined with a 2-stop GND filter to get a total of 3-stop needed), mount the filter compose and shoot. This should yield a more evenly exposed photo with good detail on sky and ground.

With these filters (GND and polarizer) the amount of light reaching the sensor will decrease so a longer exposure will be needed. Is a good idea to use a tripod, if available set the mirror lock option, and trip the shutter with remote release or the self-timer function.

[Chip]

Thank you very much, Newt.

I knew the theory behind a GND, but never knew how to figure out how many stops to use until reading your post.

Two follow up questions, if you don't mind.

(1) Am I correct that I'd put on and adjust the CPL first, and then spot meter to find out how many stops of GND filter I'd need?

(2) I'm confused about what 2 spots to select for spot metering. It seems to me that the sky is the brightest, that the foreground is the next brightest, and the shadows are the least bright. In this situation, is there a rule or guideline for which 2 of the 3 I should select for spot metering? Do I pick the brightest and darkest areas of the photo?

Thanks again. I appreciate the time it takes for you to educate folks like me.

[PhotoNewt]

Originally Posted by Chip

...(1) Am I correct that I'd put on and adjust the CPL first, and then spot meter to find out how many stops of GND filter I'd need?...

It really makes no difference since the CPL will reduce the overall exposure by a factor of 2-stops the difference in exposure between the bright parts and the dark parts will still be the same with or with out the filter on; the absolute numbers will be different but the difference will be the same.

Example:
Using the numbers from my prior post...

Without the filter the sky will be 1/500, the ground 1/60 - 3 stops difference.
With the filter the sky will be 1/125, the ground 1/15 - still 3 stop difference.

...(2) I'm confused about what 2 spots to select for spot metering. It seems to me that the sky is the brightest, that the foreground is the next brightest, and the shadows are the least bright. In this situation, is there a rule or guideline for which 2 of the 3 I should select for spot metering? Do I pick the brightest and darkest areas of the photo?...

Excellent question. Your photo present significant exposure challenges, more on the later. Lets use the most classical example of GND filter use for now, a scene with open sky and a straight horizon. With this metering is simpler since your objective is to improve the exposure of the sky without underexposing the ground (usually darker part). In this situation you can point the camera to any part of the sky making sure the sun is not in the metering area. The foreground point(s) should be metered from the area(s) you are more interested (sometimes we need to make choices when exposures are difficult) in exposing accurately.

Going back to your photo, if you align the boundary of the GND filter on the horizon this will have the effect of leaving the foreground exposed properly, decreasing the exposure of the sky therefore capturing more detail here but also making the mountain actually darker. A better compromise is to move the the boundary close to where the sky becomes visible for more even exposure results.

I would take an exposure reading from the green vegetation on the left side of the lake and another from the green grass close to the bench, look at the difference and use the average of the two as my initial exposure. The mountain on the right side will be dark do to backlighting from the sun angle and although likely to improve some with the filter use, it will still be darker than the rest because it has less illumination.

As with any tricky exposure situation, use a tripod and bracket your shot by 1/2 and 1-stop above and below to assure best results or shoot on RAW if your camera supports this format.

Your other option of course, is taking one shot exposed for the dark mountain, another for the foreground and one more for the bright mountain peak and "merge" then using an HDR software - I feel however this may produce a result that may not look too natural.

[kencaleno]

[

Your other option of course, is taking one shot exposed for the dark mountain, another for the foreground and one more for the bright mountain peak and "merge" then using an HDR software - I feel however this may produce a result that may not look too natural.[/QUOTE]

You don't need Hdr for this-Heres how to keep it natural-looking-just take two shots: (This I call DRI-Dynamic Range Increase)

With camera on tripod: meter for highlight, take a shot-then meter for shadows, take another shot.
In Photoshop, add lighter image to darker as a new layer, then:
Select> Color Range-click highlights ,check “invert”, click “OK”.
Add layer mask.
Filter> Blur> Gaussian Blur 250 pixels.
Flatten and save. You will get detail in highlights and shadows.

Regards, Ken

[Chip]

Newt - Thanks again for the complete and detailed explanations, and for your time. No other questions from me. (At least for now.)

Ken - Thanks very much for the tip. Seems almost too easy, which is good, because I'm still at the first grade level when it comes to PP work. I will remember this and give it a try the next time I'm in a similar situation.

[PhotoNewt]

Originally Posted by kencaleno

...With camera on tripod: meter for highlight, take a shot-then meter for shadows, take another shot.
In Photoshop, add lighter image to darker as a new layer, then:
Select> Color Range-click highlights ,check “invert”, click “OK”.
Add layer mask.
Filter> Blur> Gaussian Blur 250 pixels.
Flatten and save. You will get detail in highlights and shadows.

Regards, Ken

Very nice, that is even easier.

[DarrenT]

boy am i glad i stumbled on this thread tonight! my set of Grads, ND Grads and CirP arrived yesterday and i'm off to Cornwall on Monday so no time to play!

it never occured to me to actually see what the exposure difference was between light and dark to work out how many grads to use . That explanation makes perfect sence so hopefully i can make good use of it.

[RozSheffield]

Originally Posted by kencaleno

You don't need Hdr for this-Heres how to keep it natural-looking-just take two shots: (This I call DRI-Dynamic Range Increase)

With camera on tripod: meter for highlight, take a shot-then meter for shadows, take another shot.
In Photoshop, add lighter image to darker as a new layer, then:
Select> Color Range-click highlights ,check “invert”, click “OK”.
Add layer mask.
Filter> Blur> Gaussian Blur 250 pixels.
Flatten and save. You will get detail in highlights and shadows.

Regards, Ken

I know this is an old thread, but I came across it a week or two ago whilst searching the forums for advice re. filters.

I have to say Ken, I have used this method numerous times in the past ten days and it is absolutely brilliant - so easy to do!!! I've even recorded it as an "action" so THANK YOU for posting this - you've saved literally hours of my time!!

ps. I actually "cheat" even more than you suggest - I shoot the image RAW and make sure that nothing is over exposed on the histogram, then just make multiple conversions at different exposures when I get back home.