[xanda]

Hey there, havent posted for ages sry.
However, i just just this minute ordered myself a set of cokin filters including:
ND2 Grad, ND4Grad, ND8Grad, ND4 Grey, Linear Polariser.

So i thought seeing as i would love to make the most of them as soon as they arrive i'd ask for some tips
-So are there any specific techniques for exposing with nd grads? do you meter with the filter off or on?
-Any other handy tips/ advice?

Thanks, Josh

[stupot]

Originally Posted by xanda

-So are there any specific techniques for exposing with nd grads? do you meter with the filter off or on?

There are two different schools of thought on whether to meter with filters on or off, personally i meter with them on, and i get the results I'm after!

Funnily i have just read two articles on this very subject one from a monthly photo mag and the other from leading photographer Lee Frost both in support of the 'filter on' approach saying that modern DSLRs meters are sophisticated enough to deal with the filter being present.

I know there are some guys around here that swear by the 'filter off' approach so try out both and see what works for you!

[P-E]

Might be some helpful reading here;

Metering Using Filters

[Dabhand16]

Just for balance, I'll support the other side! If you consider that the reason you use an ND grad is to reduce the amount of light entering the lens, usually from the bright sky, the only way this can be achieved is to meter with no filter, set the camera manually to these settings, then put the filter on and take the picture.

If you think about an ND filter that is not a grad - just a plain ND that will reduce exposure by 2 stops all over, metering through it will have the meter thinking the available light is actually 2 stops lower than it actually is, so it will increase the exposure back to its' 'norm'. This is not necessarily a bad thing, as it will allow bigger apertures/slower shutter speeds in bright conditions if you need either of these for the shot you are taking.

As Stu has suggesed, try it both ways to see for yourself.

You might find you'll have to use manual focus with the polariser you have bought. It is generally recognised that AF systems need circular polarisers to work.

[John F]

Unless it happens to be a graduated ND filter in which case I would meter with the filter on.

[stupot]

One other thing to watch with Cokin ND filters xanda is if you stack more than one at a time, which in certain circumstances is needed they produce colour casts, a problem quite well known with Cokins.

I've notice a definite pink cast which can be annoying to say the least. Something to do with fact they dont quite reduce all wavelengths or colours equally.

Something that Lee filters dont seem to suffer from, then again they are 3x the price, get what you pay for as the saying goes!!!!

[Les Meehan]

If you are in control of your exposure technique (which you should be) then you need to meter the scene WITHOUT a Grad filter first to ascertain the SBR (subject brightness range). This information will then allow you to choose the density of Grad filter necessary to achieve your desired rendition of the scene. This must be done on a scene by scene basis since the SBR is unique to the scene being photographed.

Example: Landscape scene with interesting sky. You meter the scene using spot metering to obtain the SBR and discover that to obtain the desired detail in the scenery of the landscape the sky is going to record at two stops brighter than you would like it for your desired image. Aha! You need a grad that will reduce the sky by two stops. Get it?! This is controlling your photography and making informed decisions about how you want the image to be.

If you simply put a grad on camera and meter with it how do you know for sure what it is actually doing to the scene before you? You definitely need to know what you have first before you can know for sure how to modify it to get the result you want.

NOTE: this is talking about GRADS but the same principle applies to using contrast filters with BW film/digital BW (I`ll do a tutorial on this me thinks). The same method can make using a polariser much more controllable too.

Cheers

Les

[xanda]

Thanks for the tips and advice, very helpful.
Now i just can't wait till tommorow i hope the weather is good

[stupot]

I've been thinking about my first post in this thread and i don't think i explained the filter on approach at all in any detail, I guess I'm adding to this thread now as Les's post somewhat indicated there was no informed choices taking place or any real control over exposure with the filter in place....NOT TRUE In fact I'd say my method is a compromise between the two methods!

First of all i would meter the scene without any filter, this is a bit self explanatory as this is the only way you would know you need a filter, Generally after using filters for a while i get a feel for the type of scene that would require filters (more often than not to reduce the exposure in the sky) I'd take a few test shots metering off the foreground and can see from the info provided by my camera i.e histogram and image display what area of the scene needs to have its exposure reduced (again usually the sky). The choice of grad is decided by the info i've recieved from my initial metering and how over exposed the sky is but a good starting point is a ND4 grad (2 stops, Cokin) as this is a medium strength grad.

Then the metering with the grad in front takes place, you line up the transition zone with the horizon line and meter off the foreground once again as you are metering through clear glass you will get the same meter reading as before but with the filter in place! Then change to a stronger or weaker grad if needed but it becomes second nature to you after using filters for a while on the starting grad.

So just to set the record straight the filter on approach isn't as blind as indicated in and above post.

You meter off foreground-> pick your grad -> place filter -> meter off foreground

and having used this method it works and gives very good results!

[Les Meehan]

Stu

From your latest post it seems you are doing more or less what I suggested in my post, but as you indicate you are experienced with your method and thus get to the result you want quickly. This is to be expected.

When I write a response like the one earlier I tend to try as complete a response as possible based on not having knowledge of the original posters experience. Obviously, with those folks I do know better here, you, Rob barron, and a few others, I respond assuming experience.

So please forgive if occasionally you feel I am in some way being critical of individuals (when I am it is usually much more blatantly clear, no? ), most often I am just trying my best to give full and clear explanations hopefully for less experienced members to benefit from.

But hey, at least you were prompted to reply again which is how we all learn from and about each other right?

Cheers

Les