cars motion blur

[tecboy]

I tried to shoot pictures with a bunch of cars going as motion blur while sharp image in the background. It was in a sunny day, so I get faster shutter speed. How can I get a very slow shutter speed like about 8 seconds with the right exposure? Tips anyone?

 

[mjhoward]

Use an ND filter

 

[tecboy]

Use an ND filter

Thanks for replying, I been looking up online, and I found three ND filter. One is 0.6, and another is 0.9. There is one cost twice of more.
What are the differences?
Neutral|58mm : Lens Filters - BestBuy

 

[mjhoward]

On a sunny day, you are going to need more than 0.9 to get blurred cars, you probably want something more like this:

B+W 58mm 3.0 ND MRC 110M Filter 66-1066181 B&H Photo Video

 

[fokker]

A CPL (polarizer) filter will also help out by cutting about 2 stops of light.

If it is not a very bright day (most likely evening or morning), you may be able to get away with just using the lowest possible ISO setting and stopping the lens right down to f/22 or whatever the minimum aperture is.

 

[tecboy]

A CPL (polarizer) filter will also help out by cutting about 2 stops of light.

If it is not a very bright day (most likely evening or morning), you may be able to get away with just using the lowest possible ISO setting and stopping the lens right down to f/22 or whatever the minimum aperture is.

I tried higher f-stop and ISO 100 and still get faster shutter speed. The image is like frozen in times. I will try evening or morning with CPL.

 

[michaeljamesphoto]

I would strongly discourage shopping at Best Buy. I'm amazed they even have Tiffen, last time I passed through they had "Rocketfish" filters, made me shudder

 

[tecboy]

It is funny that many low cost lens filters says "High Quality Glass."

 

[molested_cow]

First of all, 8 seconds is quite unrealistic for the kind of shot you are looking for. You won't even be able to get a still image of the car itself. Even if the camera is mounted on the car, there will still be vibrations. I think a fraction of a second is adequate.

Like others said, an ND filter will work. I have ND 8 filter (3 stop reduction) for waterfall shots. On sunny day condition, I find that it will barely give me what I want. It would be like F13 @ 1/30 @ ISO100 or something, which I find is not slow enough for nice silky-looking waterfall.

So, I will recommend experimenting with settings to see what suits you.
For example, on a typical sunny day, you will shoot with say 3-stop less to simulate ND8 to see how the background blurs. It will be over exposed, but what you need to know is if the blur effect is good enough for you. You can then try 4-stops less to simulate ND16 and such. Also, take note of the room of ISO and aperture settings you are willing to work with. For example, if I am taking landscape shot, I will want to shoot at F8-11 and ISO200-400. For something like a moving car, perhaps F4-8 at ISO400-800. The resulting ideal ND filter type will be different then.