To Blur and Freeze

khushi2004 · Apr 10, 2004

Hi,
I want to take some shots to get blur picture and freeze the moving subject in sunny day. Okay i hv basic knowledge like to blur i need lower shutter speed like 1/15, 1/8.
and to freeze the picture i have to use higher shutter speed like 1/1000, 1/2000.
But in this both case i not sure what will be my correct aperture. And one more thing i hv aperture priority camera and i am setting my shutter speed by changing my film speed.

For example: i am taking my picture at f11 @ 1/500 this is my correct exposure now i want to blur the picture if i reduce my shutter speed to lower one it doesn't affect my picture.

I don;t want to get my picture overexposed while trying to take blur picture.
regards!

khushi2004 · Apr 10, 2004

Hi guys is there any useful link based on my question!

ksmattfish · Apr 10, 2004

What kind of camera are you using? And does it also have shutter priority mode?

You probably shouldn't be adjusting film speed to get the camera to change settings, as that will over or under expose.

If you have a starting point, such as f/11 @ 1/500th, that you know is the correct exposure, then as you adjust one setting (either shutter or apeture), you adjust the other in the opposite direction to maintain the same exposure.

If f/11 @ 1/500th is correct exposure, then all of the following give the same exposure, although obviously different aspects of the image will be changed (DOF, blur/freeze, etc...)

f/2.8 @ 1/8000th
f/4 @ 1/4000th
f/5.6 @ 1/2000th
f/8 @ 1/1000th
f/11 @ 1/500th
f/16 @ 1/250th
f/22 @ 1/125th

As one setting is adjusted to allow more light, the other must be adjusted to reduce light in order to maintain the saem exposure as you started out with.

Check out the FAQ post at the top of this forum.

Goofup · Apr 10, 2004

An even simpler way to look at it:
1) don't adjust the film speed to achieve a result unless you absolutely have to.

2) Using aperture priority is fine- all you have to do is adjust the aperture and the camera will find the correct shutter speed for you automatically! (Basically, the more open the lens, the faster the shutter speed and vice versa.)

e_ · Apr 10, 2004

Hi guys!

Great to see everything's cranking along @ TPF

I had some down time and was just passing through - thought to throw in my tuppence worth for this question

Ksmattfish explains it well but the shutter speeds (even with the aperture closed down) remain problematic

Several suggestions:

* Use a slower film

* Use a filter

* Experiment with lowering the ISO setting on camera; modern negative film should be able to handle up to 3 stops (without any change to development times¹) and still give an acceptable result

* To achieve blur with a 'faster' shutter speed - position yourself so that moving object travels at right angles to/across the face of your lens

Failing that (and having noted your wish to shoot on a sunny day) it may be necessary to wait for less light

Have fun!

è_

EDIT: (¹)

photobug · Apr 10, 2004

Hey stranger! How goes the world of photojournalism?

e_ · Apr 10, 2004

Jim!

... it's nice to be remembered, my friend. Thank you

Life is good - and work is busy

Just taking an Easter break / some gentle R 'n R

Cheers!

è_

khushi2004 · Apr 11, 2004

My camera is aperture priority i can not set my shutter speed only aperture.
Okay i tried to take some shots (running person) to get blur picture, i took some shots at f11 @1/500 (ASA 400) for correct reading and i want to test to get blur picture by reducing shutter speed to 1/8. But if i do it by film speed setting like:

I trying to reduce my shutter speed by changing film speed to get 1/8
f11@1/500 (ASA 400 what i using)
f11@1/250 (ASA 200)
f11@1/125 (ASA 100)
f11@1/60 (ASA 50)
f11@1/30 (ASA 25)

But i don; t have film speed setting below than 25 so as one expert have given me some clue that changing aperture we can make same exposure like f11@1/500 will be same as f22@1/125.
If i change my exposure setting to f22@1/125 i can reach upto 1/8 so is it correct method to do.
And what sort of things i hv to take care while making picture blur.

khushi2004 · Apr 11, 2004

so i f i take picture
AT
so if i change my aperture to f22 i can get 1/15 by reducing film speed to ASA 25.
But it will definitly harm my picture, coz i don;t hv shutter priority!

ksmattfish · Apr 11, 2004

We can help you better if you could tell us the brand/style of camera you are using. Is it film? Digital? Etc....

Big Mike · Apr 12, 2004

If you take a photo with 400 ISO film, with the camera set for 25 iso...your photos will be 4 stops over exposed. Rather than just change the camera setting, change the film. Even if you use ISO 100 film, shooting at 25 will be closer to getting the right exposure.

You could use a filter or two to cut the light and get a proper exposure at slower shutter speeds.

Maybe you are trying to get shots where the moving subject has motion blur but actually appears sharp. This is done by using slow shutter speeds and a flash. The slow shutter give the blur and the flash freezes the action. Now the catch is that your camera/flash has to have the "2nd curtain sync" option. Otherwise the flash will fire at the start of the long exposure and you will get a sharp subject with motion blur in front rather than behind.

khushi2004 · Apr 16, 2004

I hv aperture priority camera Canon AV1
and using film 400 ISO .

JPPLAY · Apr 16, 2004

What is your subject. If you want to blur the subject you must know how fast it is going. I would say use a 1/90 or 1/125 for a blur shot.

ksmattfish · Apr 16, 2004

khushi2004 said:
I want to take some shots to get blur picture and freeze the moving subject in sunny day.

I hv aperture priority camera Canon AV1
and using film 400 ISO .

Different subjects will blur at different shutter speeds. I think the general rule is that a person sitting relatively still or just moving about normally will freeze at 1/125th; obviously a speeding car will blur at 1/125th.

On a sunny day the approximate correct exposure for ISO 400 film is 1/400th @ f/16. Since your camera doesn't have a 1/400th speed it'll probably go to 1/250th @ f/16. Even if you close down the lens all the way to f/22, you are still stuck with a shutter speed of 1/125th, which will freeze most of the subjects I shoot.

So what can you do to get a slower shutter speed so that stuff blurs?

You could use a filter on your lens.

Neutral density filters block light without altering color or tone (cheaper filters probably alter it a bit). You can get them in several densities, and even stack them (although stacking filters has it's issues).

Polarizing filters block about 2 stops of light. That would drop your speed to 1/30th @ f/22 ISO 400 on a sunny day. See the thread in the "How To" forum for more info on polarizing filters.

Contrast Filters (BW only) block some light. I think the red #25s block about 2.5 stops, the yellow drops almost a stop?

You could use slower film:

Approx correct exposure for different ISO on a sunny day:
ISO 400 1/125th @ f/22
ISO 200 1/60th @ f/22
ISO 100 1/30th @ f/22
ISO 50 1/15th @ f/22
ISO 25 1/8th @ f/22

You could use combinations of the above.
ISO 50 film with a polarizing filter on it on a sunny day = 1/4th @ f/22