How can I have a 3-4 sec exposure in the daytime (raining)?

Treymac

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Hey guys.
I have a project for my photo class. I have to photograph 'time'. The instructor is looking for a conceptual photo, not so much a technical one.

My idea is to go into the city and photograph people walking the streets in the business district, in business suits. I want to do this as a long exposure to not focus on one person, but multiple people passing through. But I also want to do this in the daytime.

It is going to be done in the rain, most likely since that's what's been forecasted for the week. I also have a Cokin ND4 filter, as well as a Cokin graduated Neutral grey G1 filter. The max aperture on my camera is F/16. Shooting at iso100.

Is this going to be possible?
 
Vancouver, B.C. in October, in the rain with an ND4 and perhaps a graduated neutral density filter?? Man, you're all set!:;)

Use a tripod. Work on the shady side of the street. Stop the lens down to f/16 and set the camera on a tripod or other good,solid firm support. You ought to be able to get some neat shots of people's FEET as blurred images on the sidewalk, and their torso kind of a bit blurrier. If you go out on a bright day, you might have to wait a bit, until the evening hours, or shoot early in the morning.

If there is bright sky at the top of the frame, it might pay to use the graduated ND filter to tone that down a it. Sometimes on a city street, people will be afraid to walk in front of a camera when it is set up on a tripod, so you can also use the self-timer and trip the shutter, then appear to be reading a newspaper or looking upwards like a tourist.

If you have a need for extra credit, and you have a black plastic camera body cap, you could draw an X through the middle of it, then get a pair of pliers and a red-hot sewing needle and poke a hole through the body cap right in the center of the X,and make a pinhole lens. That'd be around f/256 or so most likely, so figure out the exposure based on 16-22-32-64-128-256 (5 stops longer time-wise than a correct exposure at f/16--and perhaps at an elevated ISO setting too, like 400 or even 800).
 
Depending on the conditions and the city the ND4 may on the borderline not be strong enough. But then with a 4 second exposure time in the rain you're more likely to record a fog like event anyway. It's easy enough to check. Go into the city sometime and record the lighting.

I could take a quick guesstimate:
- Start with sunny 16 rule. 1/ISO @ f/16 gives you a 1/100th shutter speed
- Consider the rain, if it's like cloud then you're looking at a 1-2 stop drop, in a storm probably 2-3 stops. So taking the middle option of 2 stops puts you at 1/25th
- There's a few buildings in the way too that may also reduce 1 or 2 stops of light. Let's be optimistic and choose 2: 1/6th
- Finally you have a ND4 so take another 4 stops off. That gives you close to 4 seconds :)

It's just a very rough estimate though, but it can give you an idea of how to quickly come to some guesses yourself.
 
with 4 seconds you may or may not even be able to tell its a person in the exposure.

you could add a flash to freeze motion in an instant, and then have the blur continue before and after them. just handhold a flash and target it at a specific subject in the frame as they pass through
 
I just did some experimentation, and 3 seconds is way to long to see anybody walk by. The shutter is so long, they just pass right through and you wouldn't even know they were in the shot.

Any idea of what kind of shutter speed I would need to see people? I'm thinking it might be as fast as less than a second, by with that fast a shutter speed, people wouldn't be as blurred as I want. I guess it's going to take a lot of fine tuning. I want to do this in film, so I guess I'm going to have to figure it out with my digital camera first.
 
I wish my canon dslr's had iso 25 and 50. ND filters are good for this sort of thing, but the good ones are expensive, and cheap ones just degrade the image quality, but a bad image is better than no image.

If you want to capture the motion of a bunch fo people walkign together, and photoshop is allowed, you could tak ea bunch of slow shutter pics with the camera on a tripod, slow enough to capture some blur. then later go into photoshop and mask the images together.
 
If you're looking for people, but blurred, try 1/10-1/2 second, in that range to start with. You can probably go a bit longer too but yeah 3-4 seconds will just get you unrecognizeable blurry objects.

Do you have a speedlight by chance? You could use rear curtain flash, this would give you blurry subjects but the flash would freeze them at the end of the exposure which would create a cool effect. You could try it with onboard flash but I really doubt it would have enough power for what you need to do.
 
treymac did you read my note about the flash?

Hey Rondal. Ya, I was thinking about it, and it makes sense. But my idea of 3-4 seconds is way off. The amount of time it takes a person to travel from one side of the frame to the other will be very short, maybe a second. So I'll have to trigger the flash at about half a second after the shutter. But the timing also changes according to proximity to me. Although if they are too far, and it takes 3-4 seconds to cross the frame, I won't see ghosting, since the shutter will be open for so long, the ghosting will pretty much disappear, and the only time the person will show up in the frame is when the flash hits them, in the middle of the frame.

So my goal to get all this straight it to practice fully tomorrow with my digital camera and get things worked out, then on wednesday I'm going to take the actual shots on film.

Also, would using a circular polarizer filter be enough to cut out light? If it does cut out enogh light, I think i'd like to use that instead to get an interesting look.
 
Do you have a speedlight by chance? You could use rear curtain flash, this would give you blurry subjects but the flash would freeze them at the end of the exposure which would create a cool effect. You could try it with onboard flash but I really doubt it would have enough power for what you need to do.

I do have an external flash to mount in the hot shoe, it's a Vivitar 730AFC. I don't have a rear curtain flash, although I could probably borrow one from the class. Is your idea to shoot the external flash at the curtain?

I don't know how receptive people would be to having a whole flash set up go off on them when they walk by though.
 

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