Need some reccomendations for multiple filters on a ultrawide lens

[will king]

I have a 20D and the Canon 10-22mm lens. I love shooting landscapes

at 10mm. Can anyone reccomend a filter combination that won't

vingette at 10mm? I want a thin circular polarizer and a grad ND. I

was thinking about getting a Hoya thin circular polarizer, of course

that will screw right on the lens, Cokin ring adapter that will screw

on the polarizer, and the Cokin filter holder with the Singh Ray grad

ND. How will this operate at 10mm? Is there a better solution? Keep

in mind that I typically shoot at 10mm on a 1.6 sensor and want the

polarizer and grad nd. Thanks in advanced for your help.

[chris_hutchins]

You could try one of the really big cokin lines - the pro-z is huge iircc and i doubt that'll cause vignetting!

[jimstrutz]

The thin polarisers that I've seen don't have filter threads on the forward end. That's one of the ways they stay thin.

 

You could also hold or tape a square/rectangular filter to the front of the polariser. Other than going to a huge filter type like the Pro-Z, I'm not sure how you would otherwise prevent vignetting. I know that there are plenty of photographers that hold or tape these unmounted filters to the fronts of their lenses and/or polarisers for just this reason.

[will king]

Jim, by golie I think that might be a brilliant idea. I get to save a few bucks on not buying the filter holder and it's probably going to guarantee me no vignetting. I use a tripod and cable release for landscapes so I don't see why this wouldn't work. I wouldn't mind holding the GND, but for log exposure shots, I don't think I could hold my hand steady for 30 secs or so. I can't imagine how the tape technique would work. Can you give me more details on that? Thanks.

[jimstrutz]

When I've seen tape to hold a rectangular filter on, it was gaffer tape. Duct tape would work, but might get goo on things. There were two small strips of it on the sides of the filter, and it just wrapped around the edge of the filter and grabbed the side of the lens or polariser, holding it in place. You would have to adjust the polariser first, then attach the tape to the grad, slide/tilt it where you want it, and press the tape to the side of the polariser.

 

Since vignetting occurs in the corners, the middle of the sides have some room for the tape.

 

This is only going to work with a tripod mounted camera, with static subjects, but that's probably the only times you will want to use these filters together anyway.

[jimstrutz]

O yeah, I read where one guy put some thin strips of tape on the front edge of his filter to keep it from scratching his plastic filters. I know Cokins are very soft and scratch easily.

[oceanphysics]

Forget the grad ND, take two shots at different exposures and composite them in photoshop.

 

I'd forget the polarizer too, since they give uneven, unnatural results on wide swaths of sky, but that's up to you.

[bennyboy]

Ocean Physics, I find that using an ND Grad gives a better result than mergeing exposures - this may of course just be my technique. I also prefer the workflow.

 

From his portfolio I can see that he shoots photos which include water, I imagine a polarizer may be useful for him, would you not think so? I admit it's not something I've shot so wide and am interested regarding results.

 

Will, I took the decision early on (read as 'before spending lots on screw on filters') to invest in a 'pro' filter system, I don't know if you already bought a lot of P mount stuff, but I would suggest something larger. The system I use is made by Lee, it's not cheap, but I think when I consider how much I would have paid for individual filters in sizes to fit my lens range, I've probably made the correct choice. It may be worth doing some reading up on what's available from Lee, and others, before making a decision. You can still take worthwhile photos until you have decided what to buy.

 

Contact me by e-mail if you want to discuss the Lee system more, I can probably do some test for you with my own 10-22. I have to say though, I haven't really shot with both a grad and a polarizer on this lens.

[mcgarity]

Ocean Physics is right. A polarizer and shots of the sky taken at 10mm do not go well together. More often than not you end up with a sky that looks awful. I still think you need a polarizer though. I use one regularly with the 10-22. I just don't do it at the extreme wide end very often. (And I wouldn't recommend a slim filter of any kind to anyone. Been there done that. Won't do it again.)

 

Blending exposures takes a bit of practice at first to get the right degree of feathering in the mask around transition areas. Once they learn how, I doubt many people are going to prefer to use a graduated ND filter. Some will, but most won't. Blending is actually easier and gives you several orders of magnitude more precision and control.

[bennyboy]

Got some links to example photos Larry?

[mcgarity]

http://www.photo.net/photodb/photo?topic_id=1481&msg_id=00EqjB&photo_id=4024150&photo_sel_index=0

 

http://www.photo.net/photo/3698381

 

http://www.photo.net/photo/3708854

[mcgarity]

http://www.photo.net/photo/402415

 

Thats three examples for you.

[mcgarity]

http://www.photo.net/photo/4024150

 

incomplete link in the last post.

[bennyboy]

Nice work, looks very effective. I'm just not sure I can be bothered with the amount of post processing it would involve. I imagine there's lots of monkeying involved for reflections. Out of interest, how do you define your mask, by hand, or some other devious method?

[mcgarity]

Its not nearly as hard as you think. Nor as time consuming.

 

First I use the move tool and drag the darker image on top of the lighter one while holding down the shift key. That copies it as a layer.

 

I then turn off visibility to the darker layer and make the lighter background layer active. Simultaneously hold down the ctrl alt shift and tilde keys. That generates a selection based on brightness or luminance.

 

Turn visibility of the darker layer back on and make it the active layer. At the bottom of the layers palette click on the rectangular icon with the circle inside it. That generates a layer mask with the luminance selection.

 

Hold down the alt key and click on the icon for the layer mask. You should see a black and white image on screen. This is your mask. Apply an 8 to 10 pixel guassian blur to the mask. Press the \ arrow.

 

You have now blended your two images. Time elapsed? 30 seconds maybe. You can flatten and save it at this point if you want. I wouldn't but you could. If you do it will be low in contrast and you will need to increase by a curves or a couple of other methods. Personally I prefer to go in and paint directly on the mask with black and white at this point. You get very precise control of your blending that way. You will have a better final result. Plus you don't have the loss of contrast to deal with.

[bennyboy]

That sounds quite ingenious, I've not done anything like the luminosity based selection before, the layer masks and direct painting I use a lot. Might give it a go.