jearlwebb

Hello everyone. I am a slow learner student of Photography and want to know if the "sweet spot" changes when you add a filter to the lens. For example, one of my lenses it is said the SS is at F8, if I add a filter (ND2) does that automatically change my setting a stop or two? Or, should I manually change the Aperture to F6? Appreciate any help or suggestions.

jackpi Loc: Southwest Ohio

Assume you have a proper exposure (corresponding to a specific combination of shutter speed, aperture, and ISO) of the subject before you add a filter.
When you add a two-stop ND filter: If you are in Aperture priority mode the shutter speed will automatically decrease by two stops to get the proper exposure;
if you are in Shutter priority, the aperture will open up automatically by two stops to get the proper exposure; and if you are in Manual mode, you will need to increase the exposure time by two stops, or increase the ISO by two stops, or open the aperture by two stops, or make some two stop combination of the exposure time, ISO, and aperture to get the proper exposure.

If your camera has and is set to auto-ISO, you can set both the aperture and shutter speed when in Manual mode, and the camera will automatically adjust the ISO to maintain the proper exposure.

CHG_CANON Loc: the Windy City

Using your ND example, no - neither type of filter (ND / CP) impacts the attributes of the lens. Rather, the ND reduces the amount of light reaching the sensor by two stops in the same manner as sunglasses reduces the amount of light reaching your eyes.

LoneRangeFinder Loc: Left field

Exactly. The "sweet spot" is specific to the aperture of the lens.

mcveed Loc: Kelowna, British Columbia (between trips)

The filter factor will require either a change to a larger aperture, a change to slower shutter speed or a rise in the ISO to maintain proper exposure. If you opt for a change to a larger aperture you may move closer or further away from your sweet spot. But the sweet spot will not change.

mcveed Loc: Kelowna, British Columbia (between trips)

The sweet spot IS the aperture at which your lens is the sharpest.

LoneRangeFinder Loc: Left field

I know-- just wasn't as clear as you. I should have said: each lens has a specific sweet spot determined by aperture. That sweet spot is not changed by other factors such as ND filters....

G Brown Loc: Sunny Bognor Regis West Sussex UK

You got that bit right......
well read. :-)

camerapapi Loc: Miami, Fl.

Those filters do not change the "sweet spot." If you know that sweet spot compensate the exposure for the filter and you retain the same aperture. Obviously, use a tripod.
If the shutter speed will fit the subject is another story.

romanticf16 Loc: Commerce Twp, MI

The "sweet spot" refers to optimum sharpness of the lens. When you add a ND2 and have to open up 2 f stops to compensate for it you are no longer at the "sweet spot". Your other alternative is to slow the shutter speed by 2 stops or increase the ISO by two stops, leaving the aperture at the sweet spot.

jearlwebb

Thank you everyone for your help and input!