Originally posted by pschlute You set the ISO and aperture but you don't let the camera set the exposure.
If using a ND Grad filter you need to meter for the area of your shot that will be filtered (spot metering a few areas is best) then meter for the unfiltered area. Do this before you put a filter in place. You use the unfiltered exposure reading to set your camera shutter speed, and use the difference in exposure readings to decide on what strength grad you need. Use Manual exposure mode to set this up. Focus the scene then turn off AF. Only then put the filter in position.
If using a ND filter like the Big stopper, you first take a reading without the filter. Then focus and turn off AF. Put the filter in place and use the "cheat-sheet" or the Lee phone app, or simply use your fingers to count 10 stops from the camera reading and take your shot.
The important thing is to not let the camera meter or AF to do anything once you have a filter in place.
Originally posted by TerryL Peter,
That is an excellent explanation, thank you. As far as choosing filters, should I get the Big Stopper, Little Stopper, and a few Grad ND soft edge filters? Also, do I get the mount for the Tamron 15-30? I really want to just start with a basic filters, and build from that. I'm trying to keep it under $1,000. Your help is really appreciated.
Terry
The interesting thing to note, in my experience, solid ND filter use and Grad ND filter use are two very different applications.
I use solid, or 2-4 stop ND filters, to blur motion, which in my case 99% of the time is water(falls). the Fotodiox sytem would be fine for that application and relatively inexpensive compared to the Lee or other square filter options.
The problem as I see it, instances in which I would use a grad ND are inherently variable, which is why a square filter system is a must. My horizon is never in the same place, which a fixed adapter ring grad ND filter would dictate.
As such, for my 24-70 i have some fixed ring 2-4 stop ND for motion blur AND a cokin z filter system for scene which require a grad ND. I could have gone strictly with the cokin system, but the square filters take alot more time and effort to set up that screw in filters. I have that luxury for sunset/sunrise, but not so much on waterfalls that often involve miles worth of hikes and several more destinations to shoot while factoring in travel time, food and waning light/weather. It's why i have basically two filter sets.
As far as shooting technique, I have to disagree with the concept of never touching the camera once exposure is obtained with grad ND. Especially in the case of sunrise/sunset, over the course of a shoot EV with change 4 or 5 stops at least over an hour, to and hour and a half. I am constantly adjusting shutter speed to keep my ETTR bias. I am also quite often bracketing for DoF and/or bracketing for motion blur. Some waves look better at 1/2 sec and some look better at 1, 2 or even 3 seconds. After 10+ years, I have some idea what looks better at what shutter speed, but not always, so I hedge my bets.
I am also occasionally fiddling with focal point and composition, because I only get one chance at THAT sunrise/sunset.
In summary, for the 2 hours I'm shooting a sunrise/sunset scene (I am ALWAYS on site and set up at least 1 hour prior), I'm a busy photog, between constantly reading my histogram and adjusting exposure to experimenting with different compositions. Perhaps I'm doing something wrong, but I have never been able to just set the camera on manual, lock in a shutter speed and aperture at 100 iso and constantly hit my remote shutter release for an extended period of time. MAYBE 5 mins at most....