Simple Question About Long Exposers

[fischerphotos]

How, if you can, do you take a long exposer photo (1/5 -5 sec.) in the middle of a sunny day. Like if you wanted to

take a photo of a waterfall. Is there a way to take a photo like that in the day time? Why does it get way over

exposed?

[btmuir]

Neutral Density Filters

[nick_davis]

You need to shoot through multiple neutral density filters to achieve speeds that low for sun-lit scenes. They are filters that are a neutral gray color that cut down the amount of light that is able to reach the film or cmos sensor in your camera. You can get them in various stops, usually from 1 to 4, but 5 second exposures during the daytime would require about 8 or 9 stops of ND (neutral density) so you would need to stack multiple filters.

[lex_jenkins]

Colton, take a look at the various charts on Fred Parker's "Ultimate Exposure Computer" site:

 

http://www.fredparker.com/ultexp1.htm

 

It's a lot to digest, but it'll help you understand the relationships between scene illumination, EV (exposure value), ISO (whether film speed or digital equivalent) and exposure settings.

[dlakelan]

In the absence of ND filters, you might try shooting 4 normal exposure photos, and then compositing them in post processing. The moving water will be different in each photo and should average together to form some kind of motion blur, whereas the still portions will simply overlap. I haven't done it, but in theory it could work.

[fischerphotos]

Thanks guys. And also, in theory, could you just darken it on the computer or not? I'm guessing you wouldn't get good enough details.

[guendanadxi]

Yes, in theory, but if its waaaaay overexposed, you will be losing detail in the areas with the more extreme highlights...

[Ian Rance]

I know it is just a typo, but the title of this thread made me chuckle - first laugh of the day. ;-)

[Ed_Ingold]

The statement <i>"Why does it get way overexposed"</i> is an admission that the author doesn't know much about light, exposure and the reciprocity of shutter speeds and apertures. This is compounded by the statement <i>"...could you just darken it on the computer...?"</i>

<p>

Exposure is a function of the amount of light reaching the film/sensor, controlled by the aperture, and the shutter speed. Reciprocity is the relationship between the two. When you double the amount of light (open up one f/stop) and cut the shutter speed in half, the total amount of light reaching the film remains the same.

<p>

There are limits to the corrections you can apply "on the computer." Digital sensors and slide films reach their limit with about 2 stops of overexposure. Negative film is a little more tolerant with about 4 stops of tolerance. Once you reach this limit there is no more detail to be revealed. You can darken these areas using the computer, but you don't get anything worth while in the process.

<p>

The shutter speed in bright sunlight is going to be about equal to the ISO speed when the aperture is at f/16. This is called the <i>Sunny Sixteen</i> rule. Most small cameras don't go much below f/22, so at ISO 100 your shutter speed can't go below about 1/50. The only way to get longer exposures is to reduce the light using neutral density filters. You would need a 4-stop reduction in light to get 1/4 second or so at f/22 in this example. As it happens, 1/4 second is long enough to blur a waterfall pleasantly - the main reason for seeking longer exposures.

<p>

There may still be too much difference between the waterfall and dark foliage surrounding it. In that case, you can combine multiple, bracketed exposures to create an image with enough dynamic range to have detail in both areas.

<p>

Read "The Camera" and "The Negative" by Ansel Adams for a good narrative on the basic aspects of photograph and technique.

[fischerphotos]

Thanks guys. I've never really used long exposers (spelled wrong) untill fourth of july. I took firework photos but i didn't post them because i thought they wern't thant good. I've wanted to take one of a flowing stream (not many of those in south Texas) so I was just curious. Do yall recomend I use ND filters or just shoot later in the day?

[phule]

Using ND filters would require you to purchase something.

 

Shooting at a different time requires you to purchase nothing.

 

If you're on vacation, sometimes you're not going to be at a location during ideal light, hence one use of ND filters. But if you're shooting around home, you could have 2 days worth of practice shooting in better light under your belt before FedEx or UPS even arrives...

[photo_dark]

I noticed from your profile that you are probably quite young (which is awesome!), but you could probably benefit from some reading as edward pointed out. in order to branch out from point-and-shoot photography into the realm of creating photographs, you will need to have a solid understanding of the basics.... shutter speed, aperture, ISO, white balance etc... Once you understand these, you will have the answer to your question.

 

Post processing should be leaned on to enhance a great photograph, not relied on to correct poorly shot images in the first place.

 

On another note, how does someone your age aquire an $8,000 Canon 600mm lens (and then proceed to mount it on a rebel xti no less ;)

[fischerphotos]

Well David I got the rebel XTi for Christmas last year and got the lens from my dad's multi millionare boss. He is into photography so what he wants...... he gets. He has 3 5D bodies and I know for sure a 100-400mm lens. He had the 600mm but says he is always either too close or too far away from the animal. He knew I wanted a lens to play with on my camera. So, now I have a 600mm lens!

[jpo3136b]

I wrote a response to a similar question posted by Brad Funk in this thread: http://www.photo.net/nature-photography-

forum/00Qge5

 

That one, I think, outlined some of my views. There is also an example in that thread in which one of the other posters wrote in there

about neutral density filters, as someone suggested above. The example features pictures and some exposure information.

 

I believe that exposure times have a lot to do with time of day, volume of moving water, and weather, in addition to the

other basic camera factors. Overall, I recommend at least one exposure taken with a shutter speed of 1/2"; it's a good

speed, all-around for waterfalls because it is slow enough to blur, but fast enough to trap some shadows in most

situations. Actual determinations of your times will have to be made on-site, of course; but, if I could only choose one,

that would probably be it.

 

I have many pictures of water in my photo.net portfolio. They are not great photos; but, you can review them. In them,

you will see a great many examples of a wide variety of water volumes photographed as a waterfall. Good luck. J.

[jpo3136b]

Trying the thread link again: http://www.photo.net/nature-photography-forum/00Qge5

[photo_dark]

Well, that certainly worked out well for you. Seems you have some nice deer photos and other wildlife shots with it too. You are off to a great start, keep following your dream. The Xti is certainly a great camera to start with too.