Just received my 7D and I have a question about ND filters (which of course are built in to my EX3 so I never have had to think about them).

I understand why and how they work. The question relates to which way to go (FYI, I only intend to shoot video with the 7D).

The Singh Ray variable seems like the smart/easy/convenient way to go but I read that it distorts color along with some other issues. True? Disagree? They work fine???

The other option is of course the fixed filters but there are so dang many to choose from I have no idea which two or three to get and the "measurement" system is all over the place (2X or .03 blah blah).

Could I get some specific advice on which two or three to get (58mm and 77MM lense sizes will cover things) to cover the majority of high light shooting situations?

Thanks in advance.

I wouldn't say the Singh-Ray distorts color at all, until you rotate the thing to the maximum setting, where the two polarizers cross their linear planes and you get a weird across-the-lens x-shaped vignette. There is some edge vignetting on the widest lenses due to the edges of the filter sticking out too far.

You might want to consider a Lightcraft Workshop Fader ND instead - they're specifically built to reduce vignetting by mating a larger sized filer to a flanged thread for your lens size. Also, they're cheaper. :) Of course, they also suffer from the polarizers' meeting at the maximum setting.

Seems like the are "out of stock" on everything. These people kosher?

Just make your own variable ND. It's simple. 1 rotating polarizer + 1 linear polarizer = 1 fader nd filter

Yes, it is simple to make your own - if you have a proper matte box with a rotating stage and the pricey large filter glass. If you stack your own on threaded filters at the end of the lens, you really are going to start suffering from vignetting at even modestly wide focal lengths. I find that I have to zoom to about 32mm on my 24-70mm when using the Singh-Ray Vari ND on the 5D Mk II. I can only imagine that I'd have to sacrifice more if actually stacking threaded polarizers myself.

Seems like the are "out of stock" on everything. These people kosher?
Yes, I own one, and they are definitely kosher. I've heard a theory lately that they're reworking their filters, and therefore have been trying to sell out of their existing inventory. Not sure where I heard that, though... I'm waiting on the 67mm version becoming available, so I can have some adjustable ND on my macro lens!

If you make your own couldn't you make it with a bigger filter thread than your lens and use a step up ring. Wouldn't this keep the filter borders out of the lens focal view. Just a thought....I'm all about making stuff for less than I would buy it for. :-)

I use fixed filters - 77mm's at .3 -.6. 9, etc... using step down rings.

I also have tried my own variable with 2 polarizers - and yes, it does cause vignetting and it is fiddly to get right.

For fun I ordered a complete set of 4 ND's from a Chinese supplier - advertised as high quality glass - they arrived 3 weeks later for about $30 total!! I cannot tell them apart from my Hoya-B&W ND's that cost over $100 ea.

The Singh Ray variable ND is a wonderful filter. It really speeds up the workflow by allowing 1 single filter to provide just about as much ND as you will ever need to get to the depth of field you want with the simple twist of the filter.

Compare this simple twist of the variable ND to dealing with the weight and bulkiness of matte box (although they have a lot of other valuable uses as well) and a whole slew of 4X4 ND glass filters of varying strengths and the mounting and unmounting in their frames and inserting them to get where you want to be aperture wise. Or compare to carrying a bunch of screw-in ND filters of single strengths - on and off - on and off to get to the depth of field you want.

The Singh Ray makes a "thin" model that removes the front threads for other filters to help avoid vignetting, but the only time I see this effect with the normal thickness Sing Ray is with the Tokina 11-16mm at full wide open 11mm. Going to 12mm and the problem is gone.

I have read lots of good things about the Lightcraft variable ND as well other than their recent lack of any stock anywhere. And their path to market seems a little difficult to me.

Since I am just getting into this could somebody recommend, say, 3 fixed ND filters that would be a good basic kit. Don't worry about lens size I'll work that out..I am more interested in three "grades"

Thanks

0.6, 0.9 and 1.2

I understand what folks are saying, but because of the 1.6x crop factor (due to the APS size sensor) this really shouldn't be an issue on the 7D. And, on the 5D, you can simply use a larger filter.

If you make your own couldn't you make it with a bigger filter thread than your lens and use a step up ring. Wouldn't this keep the filter borders out of the lens focal view. Just a thought....I'm all about making stuff for less than I would buy it for. :-)

Exactly. This is what you do and if people are complaining about vignetting they didn’t stop to apply any brainpower.

No Mike, what you do is use a matte box, unless of course you like unwanted flare and ghosting.

Strange...I have never come across the flare and ghosting but then again I have a nice deep rubber sunshade on it that I bought for $4. Matteboxes arn't nessisary.

I use hoods too, they have their place, but they are not nearly as effective or as versatile a mattebox and filters. Also, you'd need different filters and hoods for each lens with a different filter size - suddenly not so cost effective...

I don't understand why you would be saying this. I have a DIY variable ND that is bigger than all my lenses. I have a step up ring for all my lenses to step up into the ND. I have a sunshade that fits the ND, thus the sunshade fits all my lenses, and even if it doesn't it's $4 dude! The cheapest mattebox is see is like $200!

Let me qualify a bit...I do not do this for a living. If I was I would certainly spare no expense and purchase the "correct" equipment, also I would want to impress the client with my big camera. As it is I have to sneak a few bucks here and there to purchase the basic nessesities without making the wife unhappy with the money I spend. So you and I look at purchases for this camera in a very differant way...I'm also trying to keep a low profile because I can't afford to rent a location.

Mike, there's no right way or wrong way, but there are different ways. You go with whatever solution works for you, but don't come on here suggesting people aren't using their brains when they choose a different route to you.

I love starting a thread and then watching it wander all over the place...good stuff guys. Thanks

Mike, there's no right way or wrong way, but there are different ways. You go with whatever solution works for you, but don't come on here suggesting people aren't using their brains when they choose a different route to you.

Ok my last rebuttal...my point was someone was stating that you will get vignetteing if you go with a stacked filter solution...which is not true if you use your head and figure out that a bigger filter using step up rings solves it.

I did NOT state that they weren’t using their head because they chose a different path. That is an incorrect interpretation of a simple statement...

and I stand by my statement.

Mike, your solution using step up rings will work for some lenses, but not all. For example, I have an 11-16mm Tokina which has a 77mm thread. With a Fader ND (82mm front element) attached it vignettes at 11 and 12mm. I also have a Canon 14mm f/2.8 L. This lens doesn't have a filter thread, so again step-up rings would be useless.

Yes, these fader ND start having other issues with wide angles such as these. I do have a set of regular NDs as I get color shifts on my widest lenses also.

I know it's a video thing but I really wish companies would include in-camera ND's on their SLR's

For the record, it is very very (did I emphasize very enough?) hard to make a "variable ND" filter that does not have blue leak. This is because the process of crossing two polarizers causes the blue channel of light to leak through more than others and can wreak havoc on your white balance if you are paying attention.

I have owned a Sing-Ray for years for my own personal photography and I have to be very careful with it. It can be a good tool but you have to pay attention to the white balance details if you shift the ND level. This happens mostly at the stronger end of the ND.

Schneider does not currently manufacture a variable ND filter (as of May 2010 anyway). We have abandoned this for sometime becuase of the significant amount of blue leak that can occur in the these filters.

Be careful when you buy or use a variable ND. It can be a useful tool as long as you are aware of the limitations.

Single glass ND filters remain the purest optical solution (built-in camera NDs are made from lower quality resin or gel) and should be used whenever possible to ensure maximum image quality but I understand this may not be practical and there is a reason variable ND filters exist.

Ryan Avery
Schneider Optics

Thanks Ryan , As usual your providing extremely valuable information . Thanks again for trolling these boards.

I've just been playing with a cheap fader ND and comparing it to doubling up my own polarizers. I noticed enormous blue leak when doubling up 2 circular pols ( one was "flipped") , but didn't notice it with a linear pol in front. I will check for that though. I did see very significant softening through the cheaper filter on telephoto lenses but not bad on wide and normal. Looked OK with 2 decent quality pols though. Haven't tested very carefully yet though. Its such an attractive tool for a DSLR especially if you are covering an event where light and camera placement in daylight can change so radically and quickly.

Lenny Levy

Lenny,

Any time you use filters in front of a telephoto, the requirements for true optical flatness are exponential. This is why the big Canon tele's on DSLRs have rear drop-in filters to reduce the amount of glass that has to be flat.

IF, big IF in my opinion, you were to make your own homemade variable ND, using a circular pol in the rear and a linear pol on the front would be the correct usage. Hence why your tests with circular pols stacked front ways an back created the results they did.

Bottom line: variable NDs can be a useful and fun tool but certainly not the "pro" solution. That being said, I use 'em on occasion. :)

Ryan Avery
Schneider Optics

Using the Singh-Ray variable ND I rarely see the blue color effect discussed and when seen it is near the max setting.

And in the rare occasions where it is seen, it is a very simple thing to correct in FCP, Color, Edius, Premiere, or Photoshop for stills. Simple white balance.

Weighing the rare occurence of a slight blue shift against the big savings in time changing out filters to get to my desired DOF is well worth the occasional white balance in post.

When shooting video, we have lost the option of shutter speed adjustment to control aperture for quickly getting desired DOF. The variable ND is a pro option to quickly dial in DOF.

Matt-box filtration is superior if you have a shooting situation and budget that allows it. 4X4 filters with ND grads can knock down a sky while keeping the subject at the exposure you want. Sunset grad filters, pro-mists... and not to mention the best flare protection with flags. But then you have to deal with the extra bulk and attention a large rig can draw at the wrong time.

The right tool for the right job.