Max Stop for ND Filter & AF still works

[human1969]

Hello,

I got a 10stop ND and i know the AF doesnt work once you put it on.

For typical daylight/overcast condition,
what is the maximum # of Stop for ND filter, and the camera AF still have enough light to work ?
Using D90/D7100 if it matters.

Looking to get a bigger Kenko/Hoya ProND64/100/200/500.
(not considering the variable ND, there isnt one that is both good + affordable) :bsmilie:


Thanks

 

[edutilos-]

Just use MF and save yourself the grief.

 

[catchlights]

Yes, since you are shooting on tripod, why not to try manual focusing using live view?

that is what I do anyway.

 

[edutilos-]

It will also be more accurate than AF anyways.

 

[catchlights]

It will also be more accurate than AF anyways.

that's right, you are focusing on the sensor itself, how "out" can it be? lol

 

[Octarine]

Strangely, my AF still worked with Tamron 17-50 and Hoya ND400. Also, it is not only the amount of light but also the maximum aperture of the lens that determines whether AF still can work or not. If you must use AF, then use single AF point, focus and switch the lens to Manual. The screw in / slot in the ND filter. Works well for lenses with internal focusing.

 

[mardellion]

it also depends on the condition of the available light. screw a 10 stops during midday and you will LIKELY be possible to focus (at least on my 5D III). at night, don't need filters. but i tried a 3 stops during night too. exposure simulation helped to AF.

all in all, i reply on MF. Focus, switch to MF, then screw the filter in. Or MF, then screw the filter in.

 

[nitewalk]

Also, the camera can probably zoom in live view and that would help you to focus more accurately.

 

[human1969]

Hello Guys...

I'm using B+W ND110.
For manual focus, do you mean pre-focus then mount the filter, or after mount the filter then use MF ?

If i will to mount the filter first, the viewfinder is too dark to even compose the shoot.
I have not try LiveView though...didnt think of that.


Anyway, since i have to get another one (had the 72mm, intend to get a 82mm for other lense),
I was thinking to get a 6 or 7 stop ND that can AF.
Will make the workflow so much easier.
Currently, i will pre-frame + pre-AF, then mount the filter (sometime in awkward position), before shooting.


Really appreciate if any bro can advise better workflow.


Thanks

 

[catchlights]

Manual focusing using live view before mounting the filter.
If the shot is important, than take your time to make sure everything is alright before release the shutter.

 

[brapodam]

Manual focusing using live view before mounting the filter.
If the shot is important, than take your time to make sure everything is alright before release the shutter.

AF in live view is very accurate though. Anyway, back to the question. Since TS has said himself that it's too dark to frame the shot once the ND filter is on, just focus and frame first then shoot?

I personally use back button AF, so half press shutter doesn't activate AF. This means I don't have to play around with the AF/MF switch. I AF and frame in live view, exit live view and screw on the filter, then shoot.

 

[catchlights]

AF will still work after mounting the ND filter if the ambient is bright enough, live view will still work also.
the key is slowing down, since photographer already set up a tripod, what is the rush for? take the time to go thru the whole view finder.

 

[rhino123]

Like what other had mentioned. Do a pre-focus before mounting the filter, after pre-focus (be it AF or manual) always change your focus to manual focus so that the focus don't run when you half click again. Then mount your filter. Of course you do have to watch out for your shutter speed... if the lighting was already not that incredible, your shutter speed might go over 30 sec which was the limit of your camera (for Canon anyway, not too sure about Nikon). I normally would do 'bulb' I find that easier for me that way.

 

[Kit]

I just do whatever necessary first, then mount the filter.

 

[xjosephtbr]

If wanna shoot wide open thru the view finder on super sunny days like fro portraits. Apparently 3 stops works for me. Tried w 6 stops n ull cant see ****.

 

[swifty]

Think it will depend on the light EV level reaching the AF sensors and obvious an ND filter reduces that but it depends on how much light there was to start off with.
So its not a case of how many stop ND filter you place in front of the lens, if the resultant light level is less than -2EV which is the minimum range on the D7100 then AF no longer works.

Of course, there's still the issue of framing. Even if you could get AF to work, your finder might be too dark to frame accurately so most ppl probably do what you already do. Pre-frame and focus, filter on, take shot.

 

[human1969]

Hello Guys,

Yes, forget to mention after Pre-frame + AF, i switch body to MF then shoot.

When you AF in LiveView, does the body use the Max Lense Aperture by default,
(which is what i understand for normal AF) ?

I did came across some article that did state LiveView do give better AF accuracy,
as they are not subject to any potential Lense AF Calibration.

Did some calculation myself,
if you want a 10-30s exposure, cant run away from at least a 9 or 10 stop (or more) ND.

Regards

 

[SkyStrike]

Hello Guys,

Yes, forget to mention after Pre-frame + AF, i switch body to MF then shoot.

When you AF in LiveView, does the body use the Max Lense Aperture by default,
(which is what i understand for normal AF) ?

I did came across some article that did state LiveView do give better AF accuracy,
as they are not subject to any potential Lense AF Calibration.

Did some calculation myself,
if you want a 10-30s exposure, cant run away from at least a 9 or 10 stop (or more) ND.

Regards

IIRC, in Canon systems, unless you are in Manual mode, other semi auto modes will display in live view with the widest possible aperture, unless the DOF preview is pressed down.

For Canon (not sure about other brands), I think the Live View uses Contrast detection which has better AF accuracy. But nothing beats live view + 10x magnification + manual focus.

If it's bright enough for the AF to kick in, it shouldn't be hard to perform Manual Focusing.

What I usually do, Pre-frame > AF > Switch to MF > 10x Magnification > Re-adjust > Put on filters.

 

[ElCarnicero]

Hi i think this depends on camera because i shoot with ND with different brands and some work some not. Some show me live view like I have no ND