Long exposure question

[KmH]

What does LZW stand for?



View attachment 31634

Lempel?Ziv?Welch - Wikipedia, the free encyclopedia

 

[rambler]

Quick video lesson on Long Exposures with 10ND Filter

 

[Vautrin]

being able to focus with an ND filter on depends on a) how dark is your ND filter and b) how good is your camera

with my d700 I sometimes put a 4 or 8 stop nd filter on. this lets met shoot a daylight scene as if it's dark out, so I can go wide open and use some flash.

d700 has no problem focusing. HOWEVER i've had complaints from models that the focusing light will go on super bright (since the camera thinks it's dark out)

 

[CanonFodder]

That vid was awesome. Gotta get me a ND filter now.
Jeremy

 

[Jad]

I used a Canon 5D11 and when doing long exposures I personally like to use about -10 to -13 ND filter reduction. This can be done with one filter or a stacked combination. Beware of vignetting with wide angles lenses when stacking filters. The -13 reduction will give you about a 3 to 4 minute range for a long exposure during bright mid day conditions. I use the bulb mode because the exposure is over 30s. I first set my focus point,f-stop, in manual mode and then switch to Bulb mode. Then I put on my filter. With my Canon I can set the AF button on the back of the camera to set my focus and eliminate the shutter bottom focus activation. I used mirror lock up, switch off the lens anti-vibration mode, use a shutter release cable. With my Canon I can set it to an ISO 50 as well which helps lengthen the exposure time. You will find that the exposure times stay fairly constant from exposure to exposure in you are always photographing in a bright sunny conditions. A good thing to remember is the difference between a 5 minute exposure and a 10 minute is only one f-stop of light. So if your exposure is off by a minute or two it will still yield a fairly good exposure. One other thing I like to do is set my LCD screen to view in Black and White. This can be done under picture style and as "LONG AS YOU SET YOUR CAMERA TO RECORD IN RAW". Your RAW image will be in color while you can view the image in B&W at the time of exposure. Here is an exposure chart that will help you. Start on the left side. Let say you want a -10 reduction. Take a meter reading without your filter. Let's say that reading was 1/8 sec. Now use your chart. Find the -10 on the left and go across to where you see number under the column 1/8s. The correct exposure for a -10 stop reduction is 2 min. Click on the chart above to expand it. You can view my blog to see a few long exposures images . Two Lane Highway