# Filter advice?



## RBC5 (Jul 23, 2016)

I'm sure the collective information exists in the forums, but I wonder if someone could answer a few questions about filters. 

I've shot filterless until now, and plan on buying some. My preference is for the sharpest image possible regardless of price, and that's how I choose lenses. When adding filters, especially to the top L lenses, which company's filters would affect sharpness the least?

Does anyone lab-test the effects of filters on sharpness? 

Where's the best place to find information on the glass/coatings that filter makers use?

My plan is to purchase UV/protective filters, polarizer, and ND of various grads. No special effects (for now) until I work with the others for a while.

Thanks for any help!


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## neuroanatomist (Jul 23, 2016)

B+W is the way to go. 

UV or clear doesn't matter (for a dSLR). Circular polarizer, their Käsemann CPL is excellent, and the XS-Pro mount is very slim. 

Solid NDs are fine, I'd skip screw-in grad NDs since the that limits you to putting the horizon in the middle of the image. If you want grad NDs, consider the Lee system.


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## RBC5 (Jul 23, 2016)

Thanks. I have been leaning toward B&W, as they see to be at the top of the heap. I've seen lots of less expensive filters, so I naturally wondered if there are qualities in the glass that affect resolution just as there are in lens glass, even within companies. I'm happy to spend the money for the very best end result.


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## candyman (Jul 23, 2016)

RBC5 said:


> Thanks. I have been leaning toward B&W, as they see to be at the top of the heap. I've seen lots of less expensive filters, so I naturally wondered if there are qualities in the glass that affect resolution just as there are in lens glass, even within companies. I'm happy to spend the money for the very best end result.




Spent your money first time right. I made that mistake not trying out before.
The screw-in ND filter is not convenient to work with. My opinion!
Think about the workflow:
Setup your tripod and make your composition with your camera and lens. Set autofocus,measure the exposure, swith off autofcous on the lens, screw-in the ND filter (don't touch the focus ring of the lens!), take photo, check photo and histogram. If not ok, screw-out ND filter, switch-on auto focus on the lens, make a re-composition, new measure of the exposure, et cetera. 
Now, especially the screw-in, screw-out is a headache. 
The LEE filter system: slide in en slide out the filter. So much more easy. Downside: larger to travel with but with a good small pouch easy to handle while hanging on the tripod.  


Edit: oh, and I use B+W UV filters on my lens. Highly recommendable


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## RBC5 (Jul 23, 2016)

Cool! I had not seen the Lee system before...that looks great. Thanks for the advice!


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## neuroanatomist (Jul 23, 2016)

candyman said:


> The screw-in ND filter is not convenient to work with. My opinion!
> Think about the workflow:
> Setup your tripod and make your composition with your camera and lens. Set autofocus,measure the exposure, swith off autofcous on the lens, screw-in the ND filter (don't touch the focus ring of the lens!), take photo, check photo and histogram. If not ok, screw-out ND filter, switch-on auto focus on the lens, make a re-composition, new measure of the exposure, et cetera.
> Now, especially the screw-in, screw-out is a headache.



Or...meter, screw on ND filter, active Live View, compose and autofocus, then start exposure. If it's bright enough that a 30 s or less exposure is needed, you can even skip metering before putting on the filter. At least, that's what I do with my 10-stop ND filters.


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## Eldar (Jul 23, 2016)

neuroanatomist said:


> candyman said:
> 
> 
> > The screw-in ND filter is not convenient to work with. My opinion!
> ...


+1

It is extremely rare that I need to go beyond 30s.


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## JPAZ (Jul 23, 2016)

FWIW, 

1+ on B&W but also am favorably pleased with Breakthrough Filters. I'd use either (and I have both).

JPAZ


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## pwp (Jul 24, 2016)

+1 for B+W filters. Just be sure you're not getting a clone...so no eBay great deals! Expensive may not necessarily imply better. I've had a rough run with high priced Rodenstock filters which I got for my two recent 82mm filter sized lenses and getting uncontrollable flare at the slightest provocation. Switched to high quality though less expensive B+W and problem solved. There may well be brands out there that can match B+W, but learn from my mistakes and just head straight to what is an established, high reputation known quality.

-pw


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## RBC5 (Jul 29, 2016)

I see that B&W has a variable ND filter, XS-Pro nano mode,, that ranges from one to five stops. Has anyone had experience with this? It looks like it would be more practical than carrying several separate filters.


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## neuroanatomist (Jul 29, 2016)

RBC5 said:


> I see that B&W has a variable ND filter, XS-Pro nano mode,, that ranges from one to five stops. Has anyone had experience with this? It looks like it would be more practical than carrying several separate filters.



Depends on the focal length. If you plan on using wide angle lenses, avoid variable ND filters. Similar to how a CPL will show uneven polarization of the sky at ~28mm and wider (on FF, 17mm on APS-C), a variable ND will start to show a 'Maltese cross' artifact, which gets more evident at wider angles and darker settings. So, 28mm and 2-stops might be ok, 35mm and 5-stops might show it a bit, 16mm and 5-stops and the artifact covers the entire field. (Side note: it's not a coincidence with the CPL uneven sky polarization, since a variable ND is a stacked CPL + linear polarizer.)

Variable NDs are also rather thick, which can cause vignetting with some lenses. B+W variNDs avoid that by being oversized, e.g. the 77mm filter mounts to a 77mm thread but is actually 82mm in diameter; the 82mm filter is 86mm. That addresses vignetting, but creates another problem – using the filter may preclude using a lens hood, or require you to mount the filter after the hood. Regardless, deeper hoods make it hard to adjust the density. 

On the balance, I choose not to use a variND, the negatives outweigh the positive. Keep in mind that a 3- and a 6-stop ND will cover more than that range with equal variability. If you're using an ND, you're likely already at ISO 100, so bumping that up 1-2 stops won't affect IQ significantly.


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## mtam (Jul 30, 2016)

I have the Breakthrough screw on filter. I do find that it is quite annoying to screw on and off. I do not take a lot of photos with the filter. If I do I might have to consider changing to the LEE filters. But I am happy with the coloring on the breakthrough. There are tons of reviews on all these different filter. Make sure you read all the reviews on the differences before making the purchase


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## RBC5 (Jul 30, 2016)

neuroanatomist said:


> Depends on the focal length. If you plan on using wide angle lenses, avoid variable ND filters. Similar to how a CPL will show uneven polarization of the sky at ~28mm and wider (on FF, 17mm on APS-C), a variable ND will start to show a 'Maltese cross' artifact, which gets more evident at wider angles and darker settings. So, 28mm and 2-stops might be ok, 35mm and 5-stops might show it a bit, 16mm and 5-stops and the artifact covers the entire field. (Side note: it's not a coincidence with the CPL uneven sky polarization, since a variable ND is a stacked CPL + linear polarizer.)
> 
> Variable NDs are also rather thick, which can cause vignetting with some lenses. B+W variNDs avoid that by being oversized, e.g. the 77mm filter mounts to a 77mm thread but is actually 82mm in diameter; the 82mm filter is 86mm. That addresses vignetting, but creates another problem – using the filter may preclude using a lens hood, or require you to mount the filter after the hood. Regardless, deeper hoods make it hard to adjust the density.
> 
> On the balance, I choose not to use a variND, the negatives outweigh the positive. Keep in mind that a 3- and a 6-stop ND will cover more than that range with equal variability. If you're using an ND, you're likely already at ISO 100, so bumping that up 1-2 stops won't affect IQ significantly.



Thanks for the insight. Lots to think about. I couldn't use a hood with the Lee system either, so screw on filters might be the way to go for non-grad NDs. I'd need 2 sizes, 3- and 6-stop for each size, comes out to much less than two varios. Having shot filterless for many years, best to start slow and simple.


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## neuroanatomist (Jul 30, 2016)

Another option, if you're willing to forego hoods, is step-up rings. Buy the largest filter you need, and a step up ring for your smaller thread. I tried that, when 77mm was my largest thread. Then I got two 82mm lenses, so now I have both sizes. But for travel, I bring the 82mm filters and a step-up ring. 

I mostly use a CPL and 10-stop ND. I use a 3-stop ND to shoot fast primes (85L / 135L, 72mm filter) wide open on bright days, for outdoor portraits.


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