Luminous Landscape Forum

Site & Board Matters => About This Site => Topic started by: wolfnowl on June 12, 2009, 03:25:43 am

Title: Understanding Understanding Split ND Filters
Post by: wolfnowl on June 12, 2009, 03:25:43 am
I read through the recent addition to the site on understanding split ND filters.  A pretty good intro I thought, but there was no real explanation of hard vs. soft grads that I saw, no mention of how to avoid having a dividing line when using a hard split filter (hand holding and slightly jiggling the filter works), no mention of Singh Ray filters (just Cokin and Lee), and no mention of the Singh Ray 'reverse' grads.  Most graduated filters (soft) are clear for 1/2, then gradually go from clear to darkest at the top of the filter.  The Singh Ray reverse grads are clear on the bottom, but the top half is reversed so the darkest part is at the center, and clearing toward the top of the filter.  Why would you want one?  Let's say the sun is right on the horizon, sunrise or sunset, and the clouds above are less bright than the sunlight below them.

Mike.
Title: Understanding Understanding Split ND Filters
Post by: Gurglamei on June 12, 2009, 03:46:47 am
I am not sure I understand the benefits of grads when shooting digital. I used them a lot when shooting film, however after switching to digital I have taken to bracketing a shot with 3 - 7 exp. if necessary. It is a lot faster than attaching and adjusting grads, and it is usually a breeze to blend two or three shots together i PS. Doesn´t this give me even more options than grads? So why bother with grads anymore?
Title: Understanding Understanding Split ND Filters
Post by: pcox on June 12, 2009, 03:58:45 am
Mike -
You raise some good points. I didn't elaborate on the differences between hard & soft grads, or how to avoid a dividing line with a hard grad because those all seem very obvious to me - once you understand how the filters work from a basic perspective. Your point is taken, however. I didn't mention the Singh-Ray reverse filters since I don't personally use them. It all depends on what you're shooting, and I don't tend to shoot into the sun at dawn/dusk.

Gurglamei -
It depends on where you want to spend your time. Yes, shooting a bracket is faster in the field, but then more time is required on the back-end doing the blending. There's also a philosophical difference. I prefer to get the image looking as close as possible to the finished version in-camera, and grads let me do that. It's not an ideological thing, I just 'see' better that way, and so do many other photographers.

Cheers,
Peter
Title: Understanding Understanding Split ND Filters
Post by: adam z on June 12, 2009, 06:54:25 am
Just curious how much quality difference there is with a grad over the lens on high res cameras(like the 20mp+ DSLR's). I know a lot of photographers don't use any filters on their lenses and some have tried with and without and noticed a difference even when using very high quality filters. I assume this would still be the case with a grad in a filter holder. I assume that you wouldn't want any degredation in image quality to occur, I know I don't. I can appreciate not wanting too much time on a computer doing post though!
Title: Understanding Understanding Split ND Filters
Post by: pcox on June 12, 2009, 08:03:37 am
Adam -
I've not come across any such reports of a loss in quality when using high quality filters. I know that with my own (Lee) filters I don't see any perceptible difference in real-world shooting with or without. I'm using a 5D Mk II.

I'm sure that if low quality filters were used it'd be a different story.

In fact, just checking the filtered vs. unfiltered versions of the example image in the article, I can't detect any quality difference at 100% once both have been sharpened. The filtered version had two grads stacked, and a B&W 105mm polarizer in front of everything. So that's three filters with no visible quality loss.

Hope that clarifies it for you.

Cheers,
Peter
Title: Understanding Understanding Split ND Filters
Post by: francois on June 12, 2009, 10:27:17 am
I haven't seen any significant degradation. I use a 1Ds3 and Singh-Ray filters. I must say that I don't use GNDs very often, mostly in easy situations.
Title: Understanding Understanding Split ND Filters
Post by: DaveCurtis on June 12, 2009, 04:49:44 pm
I use a 1Ds3 and Singh-Ray filters too. I have never seen any obvious degradation either.
Title: Understanding Understanding Split ND Filters
Post by: Jack Varney on June 12, 2009, 06:19:10 pm
The one thing I don't like about using neutral density filters is that most don't leave a place to mount a lens shade.
Title: Understanding Understanding Split ND Filters
Post by: pcox on June 12, 2009, 06:22:00 pm
The Lee system includes a bellows which you can use, if you really want a lens shade.

However, I find using my hat works much better, and it's faster, too.

Cheers,
Peter
Title: Understanding Understanding Split ND Filters
Post by: Tyler Mallory on June 17, 2009, 02:58:44 pm
Quote from: Beachconnection
The one thing I don't like about using neutral density filters is that most don't leave a place to mount a lens shade.

You also can't contour the exposure change to the scene, if the area you want to cover doesn't go in a straight line. Combining 2 or 3 exposures after the fact seems to give much more control.