Four Different Exposure Times: Geneva Dam

Nothing earth-shattering, but in a morning sunrise I stood by the Fox River and shot four pictures with the Time Priority mode engaged.  The top photos is with, as I recall, 1/3 second exposure, the second down is about 1/10 second, third down 1/40 exposure, and bottom photo is 1/250 exposure.

Findings: faster exposure = darker image and more static water.  Slower exposure, more light and silky water.

I plan to get a darkening filter, which will allow silky water effect in sunlight (i.e. prevent overexposure).

What is interesting to me is, in time control mode, the camera controls the other camera settings automatically (white balance, aperture size, etc) and it still cannot overcome the extremes of time lag.  It compensates best it can, and that's it (thus bleached out top photos).  What I am still learning, though, is that if a photographer is seeking a certain type of photo--a certain photo quality or effect--they will need to control all the settings.

The camera does well on automatic, but not perfectly. It's particularly poor on auto setting if there is high contrast in the photo subject--a window behind the subject, a sunburst through the clouds, a white and black checkered background, and such.  Plenty to learn.


White Ford Falcon said...

Interesting test. As you know, the minimum aperature on a lens (large f number) is only able to compensate for so much shutter speed. Apparently at that slow shutter speed, the smallest aperature is still too large to avoid over exposure.

What I have done in the past is to force the ISO to the lowest number (100 or less) and use aperature priority mode.. set the aperature as small as possible. That will be the slowest shutter speed you can use without overexposing... at least until you get the neutral density filter (note: a circular polarizer darkens some too, but not enough in most cases). With the filter on, when you use this same method, your shutter speed will be much slower... just be sure to buy a dark enough filter or you will be disappointed with the minor change in max shutter speed.

Coolkayaker1 said...

I see. I still have issues with understanding ISO. As you stated in the past, film ISO was only good for about 800. Now, Canon 7D goes to 6400! Grainy? Yes. So, I really don;t understand enough about the ISO as a compensation for the more concrete concepts of aperture and speed. ISO is still an ambigous cloud to me. What I will need to do--and our cameras are both capable of this--is to manually set ISO, speed, aperture in fully manual setting (I think a downside of fully manual, if I am not mistaken, is that I literally will have to set everything--white balance, ISO, the works). But anyhow, I can keep everything the same, no compensation, on a tripod in a fairly fixed light setting (midday) and see what comes of tweaking each individual setting with both a moving and nonmoving subject. Much to learn. Looking forward to your photos on your website.

Coolkayaker1 said...

I used mpix for an 11x14 of the railroad bridge photo a few blogposts ago and it came out great. I will hang in my exam room. Cathy syas the subject matter and black and white is depressing and should be titled, "Cancer".


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