topic Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens in EF & RF Lenses

Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Fri, 07 Mar 2014 01:56:16 GMT

Hi, I'm looking for suggestions for a varible ND filter for my 7D EFS 17-55mm lens. Wanting to shoot video on the high end towards the f/2.8 range of this lens. Currently, my sweet spot without a ND is anywhere from f/14 to f/18 bright/cloudy outdoors. I normally shoot at 1920x1080 at 24fps with my shutter speed at 1/50. As you know, the higher the aperture the brighter things get. At f/2.8 I'm totally washed out. I have a B+W UV XS-Pro filter that currently lives on the lens https://www.schneideroptics.com/Ecommerce/CatalogItemDetail.aspx?CID=1554&IID=8160

I see Light Craft Workshop has come out with a Rapid Variable ND lately that looks interesting. http://www.bhphotovideo.com/bnh/controller/home?O=&sku=1015993&Q=&is=REG&A=details

If you have any suggestions that would give me great results, I would sincerely appreciate it. Thanks, Ray

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

hsbn — Fri, 07 Mar 2014 05:40:53 GMT

Depends on your budget, if money is no problem, Sing Ray Vari ND is pretty good but it's really expensive. Tiffen is also good. I also like Marumi filter too. But remember that with Vari-ND you don't want to use at the extreme (say 10 stop) because it will give some kind of weird effect and color cast. And take off the UV filter if you use another filter. You don't want to stack them.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Wed, 19 Mar 2014 12:09:34 GMT

Thanks for the suggestions...... I will check into the ND's that you mentioned. Your help is most appreciated. Ray

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

Skirball — Wed, 19 Mar 2014 16:39:29 GMT

Personally I'd get a standard ND filter instead of a variable. Looks like 5 stop is what you need. I know B+W makes a 6 stop, you might be able to get that to work.

Perhaps variable NDs work well with video. When I looked into getting one for stills it seemed to me it just wasn't worth it if you're picky about your quality. Anything less than the SR was of dubious quality and even the SR had problems with the X banding at higher opacities. With stills you usually have some wiggle room over settings so having a 3 stop and a 6 stop, and stacked for 9 stop, was enough for my needs.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

TCampbell — Wed, 19 Mar 2014 18:00:28 GMT

@Skirball wrote:
Personally I'd get a standard ND filter instead of a variable. Looks like 5 stop is what you need. I know B+W makes a 6 stop, you might be able to get that to work.

I'd 2nd this advice. Variable NDs work by using two polarizing filters. Polarizers block light based on the angle of the light and it's polarity. This works well at standard and long focal lengths, but at WIDE focal lengths it's a problem because the the wide angle of view means light is coming from many different angles and it's not possible to tune a polarizer uniformly for all of them. What you end up with is a dark band going through part of the image and then brighter in other areas.

If you use a standard ND filter, you're not using polarization to block light so the density is even throughout the entire frame.

I suspect you'll find that a variable ND works well somewhere around 30mm and longer... but at shorter forcal lengths (e.g. 20mm or shorter) that the effects are noticeable to the point that you probably wont like the results.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Wed, 19 Mar 2014 20:18:23 GMT

Wow..... Great info! I do want to take video as well as stills. I am looking for something to get me through both worlds, but I do not want to lose quality. You got me thinking...... Thanks, Ray

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Fri, 21 Mar 2014 14:01:26 GMT

Hi, The biggest reason I'm thinking of a VND is due to keeping video very close to the same brightness level in different shooting instances. As for portraits, landscapes, etc. I believe that a variety of fixed ND's would be fine, I could always fine tune lighting in Lightroom due to shooting in raw. I'd like to add, I use Sony Vegas Pro for all my video editing.
A couple questions do come to mind;
1) Would stacking 77mm ND's introduce vignetting?
2) Are there thin enough ND's that could be stacked without vignetting?
3) Would you suggest stepping up to a fixed 82mm ND using a 77-82mm step-up ring? I believe that this should allow stacking without the issue of vignetting. The downside would be losing the ability to use my hood.
4) As for fixed ND's, which ones in your opinion are the cleanest/sharpest?
Lots of questions I know and I thank all of you for your great help and input. I sincerely appreciate it. Ray

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

TCampbell — Fri, 21 Mar 2014 14:11:49 GMT

You can stack NDs but you'd want filters with good anti-reflective coatings to avoid ghosting. The filter rings can show up and cause vigneting when used with very wide-angle lenses (especially when stacking.)

There are a few ways to try to avoid this.

You can get filters with extra slim rings. Just be careful here because sometimes extra-slim rings don't have threads on both sides (not stackable) but many are. You'll just have to check.

B+W brand are top of the line for thread-on type filters... but there is another option if you're worried about vignetting.

You can ALSO use slide-on filters. Lee filtelrs and Singh Ray filters are two very high end makers of slide-in filters. These filters are square instead of round. You buy a filter holder and adapter ring for your lens. The ring threads on to your lens just like a filter, but it holds a bracket which typically has about 3 (but you can actually stack these to more) slots.

Incidentally, these filters and filter holders come in different sizes depending on lens focal lengths, but 100mm width is typical. E.g. you'd have a holder that can hold 100mm wide square filters. On the back of the holder is an adapter ring which you buy with the appropriate thread-size for your lens (e.g. 77mm filter thread size for the EF-S 17-55mm f/2.8 USM).

This gives you a system where the filters are substantially wider than the lens so you shouldn't have a problem with the lens picking up the edges of the filter holder.

Another nice advantage to this is that you can also use gradient neutral density filters with it (GNDs). A GND is rectangular, slides into the same filter holder, and is tinted on only half... clear on the other half. The idea being that if you're trying to take, say... a landscape shot late in the day, and the sky is still bright but the land is dim, these filters allow you to cut the light on just the sky, but the view to the land is clear. Now when you expose for the foreground, the sky isn't blown out.

I should also mention that Cokin makes the same system and Cokin is the system I remember from my youth. They're less expensive than Lee and Singh-Ray (but you did ask who makes the good stuff). I've had no real problems with Cokin filters other than the coatings and properties of the higher end filters are better. Oddly... a "complaint" I hear about Cokin is that they are hard to keep clean. Their filters seem to be formulated from some type of plastic which is a static electricity dust magnet.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

Skirball — Fri, 21 Mar 2014 15:17:28 GMT

@PaulaRay wrote:
Hi, The biggest reason I'm thinking of a VND is due to keeping video very close to the same brightness level in different shooting instances. As for portraits, landscapes, etc. I believe that a variety of fixed ND's would be fine, I could always fine tune lighting in Lightroom due to shooting in raw. I'd like to add, I use Sony Vegas Pro for all my video editing.
A couple questions do come to mind;
1) Would stacking 77mm ND's introduce vignetting?
2) Are there thin enough ND's that could be stacked without vignetting?
3) Would you suggest stepping up to a fixed 82mm ND using a 77-82mm step-up ring? I believe that this should allow stacking without the issue of vignetting. The downside would be losing the ability to use my hood.
4) As for fixed ND's, which ones in your opinion are the cleanest/sharpest?
Lots of questions I know and I thank all of you for your great help and input. I sincerely appreciate it. Ray

1) It can, and will depend on your lens/focal length. You should be ok with 2 filters unless you're shooting ultra wide.

2) They make thin NDs, but again, it will ultimately depend on your focal length. Ultrawide can have problems with a single filter, which is why they make the thins.

3) That's certainly an option. I don't know that I would do that, 77mm is such a universal diameter, I buy all my filters at that size.

4) B+W

I you using post processing for your video? You can adjust the light levels. You would have to regardless of having a variable ND, light levels vary in all but the most tightly controlled situations. THe variable ND won't help with that, you can't see brightness levels with your eyes anywhere close to the level as you will when you splice two different scenes together.

If you got the 6 stop ND filter that would put you on the far end of where you're shooting (for the settings you mentioned you'd have to open all the way up to f/2.8 to get the same light level). So if you're shooting a scene a bit darker you can bump up your ISO a fraction if needed to compensate. Or shutter speed and downscale in post.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Fri, 21 Mar 2014 20:15:17 GMT

You two are awesome!! Thanks for the fantastic information...... Lots of things to think about. I'm really starting to lean towards the fixed ND's and now possibly the slide in's. Either way it would probably be a good idea to get an adapter ring just to save my 17-55mm lens from the possibility of cross threading. I'm thinking that three filters would give me a good variation. I know a 5 or 6 stop would be good at f/2.8, but what others would you suggest to f/14? Also, are the slide-on's called the same (stops)? Again, thanks for your help. You are definately educating me. Ray

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

TCampbell — Sat, 22 Mar 2014 15:46:35 GMT

One full "stop" means that you've either reduced the light exactlly by half -or- you've exactly doubled the light (depending on which direction you are shifting.) In the case of ND filters (which obviously only cut the light) each "stop" means you cut the light in half. Two stops means you cut the light in half a second time ... 1/2 of 1/2 is 1/4. etc.

In the Lee system (and B+W uses the same notation) the filters are sold based on "density" values.

Each "0.1" worth of "density" is equal to 1/3rd of a stop in exposure. That means each 0.3 density value is 1 full stop.

Lee sells practically every conceivable density up to 0.9 (3 full stops) and then skips a bunch of stops until they get to a filter they call the "little stopper" which is actually 6 stops (because if you wanted 5 stops you'd slide in a 0.9 (3 stops) and a 0.6 (2 stops) to get 5 stops). They also sell a filter called the "big stopper" which is 10 full stops (ND 3.0).

You'll find this is typical. Most filter makers do not actually sell every conceivable stop since you can stack filters. I carry a 2 stop, 3 stop, and 10 stop filter in my bag. This pretty much covers everything.

When you get to 10 stops it's usually because you're trying to take long exposures to strongly blur things like the motion of water (that's how you get those silky/creamy looking waterfalls.) BUT... 10 stops is SOOO dark that you'll find you are not actually able to focus the camera nor even see anything to frame up the shot. When using 10 stops you have to pre-frame and focus the camera with the filter out... then slide the filter in to take the shot. If you were trying to shoot a waterfall outside in mid-day sun and no shadows, then the sunny-16 rule would apply.... at ISO 100 and f/16, 1/100th sec would be the shutter speed. But a 10-stop filter would let you shoot at ISO 100, f/16, and a full 10 second exposure (plenty of time to create a lot of blur.) In less than full mid-day sun (a stop or two lower) and the exposure quickly turns into a 20 or 40 second long exposure. During the golden-hours when light may be chanigng rapidly you could easily exceed a few minutes. A 10-stop filter is "strong juju!" 😉

You can go to the Lee filters website to learn more about the system and you'll also see lots of "grad" filters (clear on one half... dark on the other) and you can get these in "hard" edges and "soft" edges (which is how fast it transitions from light to dark.)

Singh-Ray makes "reverse grads" -- I've not seen those from anyone else. Reverse grads are clear on one half (like other grads) but then they are ESPECIALLY dark in the middle and then fade to a weaker density as you get to the far end (most soft grads would have weak density in the middle and get strongest toward the end). These filters are mostly made for sunset shots... the idea is to heavily cut the brightness of the sun when it's on the horizon, not cut the foreground landscape at all, and then apply less of a cut to the sky high above the sun.

The filters and holders are interchangeable but they do come in sizes. E.g. Lee's standard size is 100mm wide (and the square NDs are 100x100mm, but the grads are longer (I think they're 100x150mm) so that you can adjust where you want the grad tinting to star in your scene (they're just held in with friction). In the Singh-Ray filters, they come in standard sizes measured in inches but it turns out 100mm = 4" for purposes of sizes (technically it's 3.93 inches but the holders fit because it's so close.)

If you go to the Lee filters website you'll see the filters, filter holders, etc. and get a much better idea for how the system works. You cannot buy the filters from them directly... you have to go through a dealer. This is the same company famous for their flash gels (and also theater gels) used to color the lighting.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Sat, 22 Mar 2014 22:10:59 GMT

A huge thank you Tim.....!! I sincerely appreciate you taking the time to explain how these filters are registered in value. So far a 5 stop or 6 stop looks like a good way to go wide open at f/2.8. Silky water/water falls would be awesome for some of the shots I do, therfore a 10 stop as you mentioned at f/16 would be a great combination for a good background along with it. Now I need to decide what I want for shots around the f/5.6 to f/12. I'll look at the Lee filters website for further information. Thanks for all your help....Ray

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

Skirball — Mon, 24 Mar 2014 16:06:41 GMT

I’d start at 5-6 and go from there. Remember you can adjust the other variables – like ISO and shutter speed, if you want to shoot at a higher f-stop.

The 10-stop filters are a different beast. As Tim mentioned, you have to pre-focus. I don’t do this type of photography, but if I did I think I’d get a slide in filter instead. It’d be a pain to try to delicately screw in a filter without moving anything. But for my more transparent ND filters I prefer the screw in type.

Re: Needed Varible ND Suggestions For 7d EFS 17-55mm Lens

PaulaRay — Mon, 24 Mar 2014 18:14:55 GMT

Hi, thanks for the reply..... Good point about the 10 stop. Thanks again, Ray