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I am really happy with the bokeh of the 85 f/1.2 L II. However, f/1.2 could be subject to over-exposure if using outdoor, even if I change to use lowest ISO and very fast shutter speed.
So should I get a ND filter to stop down? If so, what Attenuation Factor should I get?
How about stop down on Exposure Compensation?
Any other suggestions?
Thanks in advance!
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Originally Posted by waving_odd
Yes.
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Originally Posted by waving_odd
I find that 0.9 is usually enough to get the shutter speed down to 1/4000 or so.
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Originally Posted by waving_odd
That wont do anything if your shutter speed is already as fast as it can go.
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Originally Posted by Daniel Browning
So yes, you need an ND filter. Note that a circular polarizer gives about a 2-stop reduction, and if necessary (on an 85mm lens) you can stack filters as long as the mounts are reasonably thin. With an L lens, you'll definitely want a high-quality filter, such as B+W MRC or the higher-end Hoya filters.
Thanks Daniel and neuroanatomist.
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Originally Posted by Daniel Browning
So 0.9 is 3 stop reduction. Would the reduction be too much by your experience? Heard froma well known online filter reseller that B+W's 0.6 is the most popular ND filter in photographic work. So is 2 stop a more popular choice?
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Originally Posted by neuroanatomist
That's exactly my concern too. Currently there is a B+W XS-Pro UV 010 on my 85mm glass. It's thin -- 3mm. But since they don't have CPL nor ND on XS-Pro slim mount yet, I could only stack another regular F-Pro (5mm) CPL/ND on it. Of course I can take away the UV to avoid stacking. But it's really inconvenient. [:(]
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Originally Posted by waving_odd
Not for me.
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Originally Posted by waving_odd
That makes sense.
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Originally Posted by waving_odd
Be aware that flare and glare is increased by having a UV filter (no matter how good the coatings are).
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Originally Posted by waving_odd
I definitely suggest removing the UV when you use ND, otherwise the flare will be even worse.
Yes, 0.9 is a 3-stop reduction. In my experience, 2 stops may not be sufficient, especially at f/1.2 (even if you are stopping down the aperture a little for more DOF). Consider - if ISO100 and 1/4000 shutter speed is over-exposed, and you want to keep the same aperture and the ISO is already on the floor, adding a 3-stop ND filter will take you to 1/500 shutter for the same overexposure - i.e. you've got a lot of latitude to darken when 1/4000 at ISO100 is overexposed. If that's under-exposed, you can bump the shutter or the ISO one stop and you're set. More likely, with an f/1.2 lens, you'll run into a situation where 3 stops is not enough - in that case, you'll either need to stack the ND and CPL for 5 stops, or consider a stronger ND (next in the B+W lineup is the 1.8, 6 stops).
In the 72mm filter diameter, the B+W 0.6 (102) is about half the cost of the 0.9 (103) - $40 vs. $80 - and I expect that accounts for the 0.6 being 'the most popular'. Personally, I prefer the 0.9 because if I want 2 stops I can use the CPL (rotated so it doesn't polarize, if necessary).
Have you considered the expensive option of the Singh-Ray variable ND filter? Basically CPL and linear polarizer stacked, meaning you can go from about 2 stops to completely black (8 stops in practice). It's 77mm so you'd need a step-up ring (and be unable to use the lens hood), but with larger diameter vignetting wouldn't be an issue.
Vignetting might not be an issue anyway - what body are you using? If it's a crop body, with an L lens you will probably not see much vignetting even with stacked filters.
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Originally Posted by neuroanatomist
That's a good point!
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Originally Posted by neuroanatomist
Another good point. And I suspect that many other users are also using it for f/1.8 (popular for Nikkor and Canon's glasses) or even f/2. Then 0.6 might be enough... Just my 2 cents...
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Originally Posted by neuroanatomist
With $400 (filter + step-up ring), I rather save up another 1 grand to get 50mm f/1.2 L. [;)]
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Originally Posted by neuroanatomist
I switch using it between 5D2 and 40D. But since my 24-70 needs the full frame more than this 85mm, I think you hit the bull eye that the vignetting might not be an issue as they are cropped out in the first place.