Neutral Density Filters

[neuroanatomist]

You cannot meter or AF through a 10-stop ND filter (at least, I can

[btaylor]

Denise, neuro is correct - you cannot autofocus using this filter. You can JUST (read: barely) see through the viewfinder to compose provided you have a bright day. I do the same as John, focus at the hyperfocal distance using the lens scale, most of the time but otherwise you will have to compose and focus then attach the filter. It

[Sean Setters]

Since Live View on the 7D simulates exposure, you could set up a tripod and use Live View set to an exposure of a few seconds (whatever enables you to see the shot on the LCD) and use 10X focus magnification to manually focus with the heavy ND filter. I just tried it with my LCW Fader ND and it worked decently well.

[neuroanatomist]

I did a brief test indoors just now. With the 7D and 17-55mm, I selected an aperture that gave a 1/30 s exposure, so the 10-stop ND should meter at 30 s. With the ND in place, the scene was way too dark to compose in the VF, AF did not work, and the metering sensor underexposed at 8 s. Live View with exposure simulation was still too dark to compose (Sean, I guess the full 10 stops exceeds the capability of the gain for the simulation, unlike the max density of the fader), AF still did not lock, but the metering off the image sensor was actually correct at 30 s. However, I should mention that I do recall trying this when shooting landscapes, and Live View on the 7D still underexposed.


Then, for kicks, I tried the same test with the 5DII and 24-105mm, at ~27mm so the framing was the same as 17mm on the 7D, and with an aperture set to result in 1/30 s exposure as before. Through the viewfinder with the 10-stop ND in place, the 5DII metered underexposed, more than the 7D at 5 s, and thus outside of the 2 EV exposure compensation range if one was shooting in Av mode. However, the 5DII

[Sean Setters]

Neuro-


Now that I think about it, I didn't have the variable ND filter set all the way to max. I remember turning it to the point where it was dark enough so that I could barely see through the viewfinder, but as I was indoors, the ND might not have been that strong.


EDIT: Ok, just did my test again. The LCW advertises a neutral density strength between 2-8 stops. I could not focus using Live View at the max setting. I was, however, able to focus at the point just before max. So, as Neuro said, using Live View with a 10X ND filter is not possible. However, it looks like it would be possible somewhere between 6-8 stops.

[ddt0725]

Thanks guys for the info! I think I might go with the Genus ND Fader Filter (2-8 stops) this month and then get the 10-stop B+W ND filter in the spring when I

[Sean Setters]

UPDATE: B&H sent me an email stating that the manufacturer is unable to give them an expected delivery date for the 58mm Genus ND Fader filter. So, I had them change the order to the 77mm one instead. On the one hand, I won't be able to use the filter with my 85mm f/1.8 or 50mm f/1.4 lenses. On the other hand, I will be able to use it with my 70-200mm f/2.8 L IS, 17-55mm f/2.8 IS, and 10-22mm f/3.5-4.5. Honestly, I will never use the ND on the 10-22. However, I look forward to using the Genus 77mm Fader ND filter on my other two zoom lenses.