Using filters to slow down shutter speed

DadaKopf

I like using my 50mm EF f1.8 on my 400D as a telephoto with a very shallow depth of field for some discreet street photography.

Problem is, in daylight, even at 100ISO the photos can often be exposed.

Is it possible in those circumstances to use a neutral density filter (or something) to reduce the exposure by a few stops to prevent overexposure (and fix up in RAW editor later)?

Anouilh

I don't know enough about the science of filters to be of much help with this. However, this might be useful.

http://www.geocities.com/cokinfiltersystem/gray_nd.htm

Are you not using "manual" setting, which allows you to control aperture?

http://www.mir.com.my/rb/photography/fototech/apershutter/aperture.htm

Ghost Train

can't think how else you would do it, if the shutter speed isn't fast enough and you want the apature at f1.8

DaireQuinlan

DadaKopf wrote: »

I like using my 50mm EF f1.8 on my 400D as a telephoto with a very shallow depth of field for some discreet street photography.

Problem is, in daylight, even at 100ISO the photos can often be exposed.

Is it possible in those circumstances to use a neutral density filter (or something) to reduce the exposure by a few stops to prevent overexposure (and fix up in RAW editor later)?

Whats the max exposure speed of the 400D ? Just a rough calculation off the top of my head, on a sunny day in Ireland you could ordinarily shoot at 1/100 at F/11 at asa 100. At F/2 this would translate to about 1/3200 or so. Does the 400D go up to 1/4000 ? Maybe you just need to take more care metering than you are at the moment. Camera meters aren't infallible, there are some cases (strong backlight, dark subjects etc etc) where the meter might be fooled and under or over-expose.

CabanSail

A ND Filter would help you reduce the shutter speeds.

They come as ND2, ND4, ND8 etc. The number is the divisor for the light.

ie.
ND2 will reduce the light by 1/2 ... so 1 Stop
ND4 will reduce the light to 1/4 ... so 2 Stops
ND8 will reduce the light to 1/8 ... so 3 Stops
etc.

Anouilh

DaireQuinlan wrote: »

Whats the max exposure speed of the 400D ?

http://www.imaging-resource.com/PRODS/XTI/XTIA.HTM

Shutter 30 - 1/4000

Anouilh

DadaKopf wrote: »

I like using my 50mm EF f1.8 on my 400D as a telephoto with a very shallow depth of field for some discreet street photography.

The advantages of your technique are not obvious to me. It would be great if you had a moment to post some of your work to the "Combing the Streets" thread. Is it that using shallow depth of field makes one particular subject stand out from the crowd?

melekalikimaka

Anouilh wrote: »

Is it that using shallow depth of field makes one particular subject stand out from the crowd?

exactly

DadaKopf

I should have said: If I am shooting at 100ISO at f1.8.

Thanks CabanSail, that answers the question.

TheDriver

I was out taking some shots of a cove in daylight one day messing and horsed on 2 cpls and an nd8 and an nd4 and i managed to get the camera to agree with a 10 second exposure time and in fairness, apart from vignetting, it turned out an ok shot, mad smokey sea

Mycroft H

Neutral Density filters are your friends.

An ND filters are also useful on cameras with a slower shutter sync speed, eg >1/100 seconds. This will allow you to use fill flash in bright conditions.

They were about 12 euro in Gunns a while ago