Are filters needed?

[Helen B]

You seem to be saying that a ND grad filter is "less precise" "linear and fixed" and that nature does not always comply by providing a neat line..."

That sounds extremely contradictory to me. Moreover since you can move the placement of a ND grad filter to suit your preview, how is it "fixed"? Grad filters do not have any neat line either.

skieur

We both know exactly what ND grads are. As I mentioned earlier in this thread, I have a set of rectangular Schneider ND grads.

What is 'fixed' about them, you ask. I know that they can be moved along the long axis, and rotated. That's obvious. The number of stops of difference between the clear part and the full ND part is fixed. As I explained in a previous post in this thread: "In addition, each filter has a fixed exposure effect and a fixed rate of change of effect (hard/soft grad)." You need different filters for different densities.

The graduation is in a straight line, ie linear. Surely you aren't arguing with that?

The lack of precision is in comparison with exposure blending. Exposure blending can be applied very precisely in terms of both exposure and position in the frame. You can match the transition between the exposures to the image very precisely. You can't do that with a graduated filter.

Best,
Helen

 

[PaulBennett]

Can filters fix problems and create effects that post processing cant? ...

Hate to get in the way of a good fist fight but feel you question deserves an answer.

And the answer is: YES.

For example, consider horizontally polarized light reflecting from a car fender in your picture. It cannot be removed digitally, no way, no how, but is easily removed by a polarizer before it enters the lens. Samo samo for unwanted light of a particular wavelength. Once it enters the lens, it's inextricably mixed forever.

 

[theadamsociety]

I just wanna say to the original poster that even if you aren't using filters I would say at least an A1/UV is necessary, in a logical sense. The glass in your lens is worth alot of time and money, an A1 is 10-40 bucks (depending on filter size) and who cares if you scratch it.