grad filters and metering?

[liverlipsyyz]

hi. i have a question about grad filters and metering. i am going to purchase some nd grad filters and try my hand at some landscape shots this weekend. here are my questions:

1) if i can only buy a couple of nd grad filters, which ones should i get (1 stop, 2 stop?)?
2) should i also buy a circular polarizer?
3) how do i know which stop grad filter to use?
4) should i shoot in aperture priority or manual?
5) how should i meter?

thanks for any help you can provide!
liverlips

[dcclark]

Liverlips -- Here's my take:

1) This depends on what you want to do -- do you need maximum light absorption, or just a little evening-out in extreme situations? My general advice is, don't be wimpy -- if you're going to absorb light, ABSORB it! I have a 2 stop ND grad, sometimes you may find a 3 or 4 stop one useful as well -- but 2 is generally good. 1 stop is next to nothing. I would buy just one filter at a time so that you can get used to playing around with it, and decide what else you need.

2) Polarizers are nice. The are sort-of Neutral Density (but obviously not graduated), and have the additional bonus of reducing glare. I think they're essential to just about any outdoor photographer's kit.

3) Experience. You need to get out, shoot some landscapes, and see whether your photos are becoming unbalanced because of lighting problems. If so, you may need more absorption. Or you might just need more experience with your camera -- filters are not a panacea.

4) Again, depends on experience. If you're shooting sunsets (for example), I'd use manual. Otherwise, might as well stick with Aperture-priority and control the most important variable for lansdscape use -- aperture. My general advice is, don't bother with full-manual unless you actually need it.

5) Using your camera's meter, as usual. The grad may cause it some confusion, but you can just take a test shot and see what happens, then use exposure compensation.

Good luck!

[AoxoA]

You can use A for these, set your aperture to what you'd like to use.

Meter your sky or 'bright' area. Take note.

Meter your foreground darker areas. Take note and compare the difference to the sky/bright meter.

So if the sky meters out at about 1/2000, and your darker area meters around 1/15, then you have 7 stops of difference. Bring that down to 4-5 stops of difference and you'll be golden.

You can also stack them, so a +2 and a +3 will make a +5 change.

AoxoA

[dimitrz]

Originally Posted by AoxoA

So if the sky meters out at about 1/2000, and your darker area meters around 1/15, then you have 7 stops of difference. Bring that down to 4-5 stops of difference and you'll be golden.

AoxoA

AoxoA can you or someone else explains what exactly you meant here.
If I am counting shutter speed then between 1/15 to 1/2000 there is more than a difference of 7 , therefore how did you arrive at 7 ?

1) Now when you say a Stop, are you referring to the EV value if that’s the case again how you got a difference of 7 here?

2) How do you bring down 4 to 5 stops or rather what do you mean by that ? are you advising us to reduce the EV value by 4 or 5 thereby underexposing the shot ?


I tried to do a research on this but there are so many stops in photography that now I have forgotten the definition of stop

Can someone provide some guidance to what seems to be a good advice given by AoxoA

[kencaleno]

7 EV stops from 1/15 to 1/2000 is correct:

Starting at 1/15 you have 1/30;1/60;1/125;1/250;1/500;1/1000;1/2000
7 EV stops difference.

Here's how to solve the problem if you don't have ND grads:

Ok, so you are going to have problems if some images you want to make, are outside the dynamic range of the camera: So here's the plan for that:
With camera on tripod: meter for highlight, take a shot-then meter for shadows, take another shot. In Photoshop:
1. Add lighter image to darker as a new layer,( click on Move tool, hold down "shift" button, and drag lighter image over to darker, then release) then:
2. Select> Color Range-Click highlights
3. Check “invert”, click “OK”.
4. Add layer mask. Click on layer mask
5.Filter> Blur> Gaussian Blur 250 pixels. Click "OK"
Flatten and save. You will get detail in highlights and shadows


Regards, Ken

[dimitrz]

Thanks Ken , you jolted my memory about the correct way to read stops ( silly I was thinking of 1/30, 1/60, 1/90 )

and thanks for the tip on how to compensate for a Grad filter

However what about the above step by AoxoA, will that work if from 1/2000 I reduce 4 or 5 stops and bring my shutter speed to say 1/125

and in such a scenario where do I focus , do I continue to to focus on the subject of interest in a landscape or somewhere in the middle.

[kencaleno]

Originally Posted by dimitrz

Thanks Ken , you jolted my memory about the correct way to read stops ( silly I was thinking of 1/30, 1/60, 1/90 )

and thanks for the tip on how to compensate for a Grad filter

However what about the above step by AoxoA, will that work if from 1/2000 I reduce 4 or 5 stops and bring my shutter speed to say 1/125

and in such a scenario where do I focus , do I continue to to focus on the subject of interest in a landscape or somewhere in the middle.

No, If your dynamic range is 7 stops, then it's outside the range of your camera's meter ( 5 stops)-if you reduce that range,your exposure will be wrong. As for focusing, it is usually recommended to focus 1/3 of the distance into the scene-in image 1 below using an imaginary grid is one way-the other is to use hyperfocal distances-for example with a 18-55 kit lens at 18mm setting all will appear acceptably sharp from 2 feet 6 inches to infinity,when using an aperture of F 11 second image below is a pair of charts I made showing hyperfocus points for 18-55 and 70-300 kit lenses on all focal length settings.


Ken

[dimitrz]

Awesome

Ken do you think you can post a larger file ? the current one is too small to read properly

[kencaleno]

ok, here goes