How can we decide which shutter speed to be used

[kranthi54321]

Hi all,

Hope everyone is enjoying the day!!!

I have a small query or doubt that while taking a shot, How should we have to decide that which is the perfect shutter speed to be used while taking a shot.

Looking forward for your information.

Thanks in Advance.

Regards,
Kranthi

[Sahil]

It depends upon the light available and movement of the subject. Remember, if the slow shutter speed is used the camera has to be kept on a stationery object, preferably a Tripod .

[carregwen]

With the exception of moving subjects where you want to capture movement by some blurring, you should try to get a fast shutter speed as this will avoid camera shake and subject movement. Using a tripod is a really good idea, but it's not always possible and can hinder creative angles.

To get a fast shutter speed you may need to compromise on ISO (which can lead to more noise), and aperture (which can change the depth of field). Most photographers seem to set AV mode as the main priority, and then try to improve shutter speed by increasing the ISO and/or introducing more light to the subject. With practice you will get a better feel for what is right, but you do need to understand the relationship between shutter speed, aperture and ISO. A 'good' exposure (irrespective of the light conditions) will always require a certain exposure level. How you get that exposure for that shot depends on the balance between ISO, shutter speed, and aperture.

[Shadowman]

Also, longer lenses require shorter shutter speeds or you will get blurry photos.

[GiantTristan]

A good rule of thumb for hand held exposures is that you should use shutter speeds no slower than the reciprocal of the focal length of your lens. For a 100 mm lens the shutters speed should be no less than 1/100 seconds. Obviously you have to take into account the crop factor of your camera. For a crop factor of 1.5 you would want to keep the shutter speed above 1/160 seconds.

[Geoff F]

While Tristan's recommendations are a good starting point, you can usually get away with a little bit less if you have an image stabilised lens, although exactly how much can be variable.

But when it comes to photographing moving subjects things start to get more complicated.

I suppose as a starting point perhaps a walking person needs at least 1/250 with double that for a gently running subject. A slow gliding bird would require 1/500 to 1/1000 and at least 1/1500 for a bird with flapping wings.

And, of course, if you are moving that motion has to be added to the calculations. From a boat I generally reckon that photographing anything requires at least 1/500 on a calm day. So photographing a gliding bird from a gently moving boat would require around 1/1000 minimum.

It is really all a matter of experience though; but if in doubt I prefer to allow a little bit extra for safety.

[William W]

Hi all, I have a small query or doubt that while taking a shot, How should we have to decide that which is the perfect shutter speed to be used while taking a shot.

This is NOT “a small query”.

The decision is based upon several factors.

Two of the main considerations is to give (or not give) the outcomes of:

> 1. SUBJECT MOVEMENT
> 2. Camera Motion (SHAKE)

But the decision of what to the “perfect” shutter speed to use in any situation is also dependent upon the other two ELEMENTS of EXPOSURE – Aperture and Sensitivity (ISO).

And most importantly, the range from which you have to choose all three components of exposure is dependent the EV (AMOUNT of Light) you have available to you.

***

The Aperture and Sensitivity you have available to you are largely dependent upon the Lens you are using and also the Camera you have – a kit zoom might only have F/4 as the fastest aperture available – a consumer DSLR might only have ISO1600 to work with . . . a Professional DSLR and a fast Professional Prime lens might have ISO12800 and F/1.4 – so the Pro kit gives a combined 6 stops MORE latitude in selecting a shutter speed in low light, for example.

So in low light, just as one example, a kit lens and a consumer camera might NOT ever be able to provide that “perfect” shutter speed. (example coming later) [*1].

***

Getting back to how to choose – then in regard to both Subject Movement and Camera Shake, there are limits – and one has to know what those limits are.

For example for Subject Movement the limits are (in simple terms) determined by the speed of the Subject, the Direction of the Subject relative to the Camera and the Distance of the subject from the camera:

As a simple example – you photograph someone WALKING SLOWLY TOWARDS you, but they are about 10 ft away and you have a normal lens – so you get a full length shot – you will need about 1/250s to make the arms seem as though they are frozen. BUT if you take the same camera and lens and look up and photograph a jet fighter plane travelling ACROSS the camera at Mach1 you could use 1/60s and the plane might appear stationary, simply because it is so far away . . .

So it is not as simple as Fast Subject = Fast Shutter Speed.

But in general . . .

> The closer the subject is to the camera - the faster the shutter speed required to (appear to) freeze subject
> The longer the FL of the lens used - the faster the shutter speed required to (appear to) freeze subject
> The faster the subject is moving - the faster the shutter speed required to (appear to) freeze subject
> The more the subject is moving ACROSS the camera - the faster the shutter speed required to (appear to) freeze subject
> The greater the enlargement of the final print - the faster the shutter speed required to (appear to) freeze subject

On the matter of camera shake, and shooting hand held (leaving aside IS or VR or other Image Stabilization):

> The closer the subject is to the camera - the faster the shutter speed required to (appear to) arrest camera shake
> The longer the FL of the lens - the faster the shutter speed required to (appear to) arrest camera shake
> The larger the enlargement of the final print - the faster the shutter speed required to (appear to) arrest camera shake
> The more incapable the shooting technique (breathing, stance, bracing) - the faster the shutter speed required to (appear to) arrest camera shake

The Kodak Professional Photo Guide, has three pages devoted to Limits for Tv and Subject Movement, Subject Speed and Subject Direction and Camera Format [*2]

***

So that addresses “Perfect” Tv (Shutter Speed) to avoid movements – but what if you want movement – like the flowing water fall or to make the sense of speed ? ? ? Then you might purposefully choose a longer shutter speed to enhance the image (5D 200mm: F/4 @ 1/15s @ ISO800 Tripod, Mirror up, remote release):



***

Note that the above shot was NOT panned - that was purposeful - the Subject Blur is meant to convey the aspect of the speed . . .

When panning, the "perfect" Tv has to be selected to adequately freeze the subject - but be slow enough to still blur the background [INSERT] (I don't have an example easy at hand - maybe later

***

Also there are cases where the "perfect" shutter speed to convey speed and power of the Subject, might be an extremely fast Shutter speed and also a really sharp capture of the action, at its most powerful point of motion (and usually combined with a very shallow DoF)

"Training at Sunset" 20D 200mm F5.6 @ 1/2000s @ ISO400 Av Priority Hand Held:



***

On the matter of the relationship between Av (Aperture) and Tv – it might be that the “perfect” Tv is simply a function of the Av you choose – what I mean is if you want a shallow DoF (Depth of Field) portrait then the PRIMARY consideration is the Av. So you might decide that you need about F/5.6 for the DoF you want, and you also want to use then LOWEST ISO you have because you want the least noise, because you want a really large print – so let’s assume you meter the face of the subject and get: F/8 @ 1/100s @ ISO400 . . .

Now that translates to F/5.6 @ 1/200s @ ISO400 . . . and F/5.6 is what we want but we also want the LOWEST ISO possible, so we choose F/5.6 @ 1/25s @ ISO50 . . . BUT that Shutter Speed makes loud alarm bells in my head . . . because 1/25s is beyond my "safe limit" for Handheld when using a 50mm lens for a Tight Head Portrait – so I chose F/5 @ 1/50s @ ISO100, because 1/50s was safe and therefore the “perfect” choice in this shooting scenario.

But in this example, it was the F/5.6 Av I required for the DoF and then the necessity of getting the LOWEST ISO which were the driving factor of the choice of that 1/50s Shutter Speed

(Finally I used F/5, becasue I wanted 1/3 stop over exposed on the lit side of her face)



***

Footnotes:

[*1] On the matter of never being able to get to the “perfect” shutter speed – I was happily shooting this swimming meet at around F/4.5 @ 1/1250s @ ISO1600 using my 70 to 200F2.8L and then a circuit breaker tripped and the floodlights went off . . . I needed a shot of the Swimmer in Lane 6 Starting at a Backstroke Start. Now I know that 1/800s is close to the absolute limit for a Backstroke Start - my 70 to 200 F/2.8L was useless in this situation – as with the camera I was using I could only increase my ISO to ISO3200.

So I ditched the 70 to 200 and used my 85mm and crept as close as I could under and near one of the Judges. Tech: F/1.8 @ 1/800s @ ISO3200: the 70 to 200 F/2.8L was useless in this situation as I needed to hold 1/800s as the “perfect” shutter speed – if I had not had a faster lens, I could never have made the shot.



***

Similarly . . . This was shot early morning New Years’ Day about 0100hrs:



I had finished shooting a Corporate New Years Function (inside) and had taken a stroll to get some air. I had my 5D the 135L was on it. I also had a refreshing Scotch and Ice in my other hand – fringe benefits of a job well done and completed.

I saw this guy playing with his kids and the sparklers and I liked the shot . . . So I fiddled a bit one handed and took a spot meter reading on his face – but I had to move fast because I did not want to loose the moment it was very dark not very much street light reflection or moon ambient at all - the meter reading off his skin was something like F/2 @ 1/30s @ ISO3200.

I though “crap” – I knew I could NOT pull 1/30s one handed with a 135mm lens, (Camera Shake) I did not even want to try 1/60s or even 1/80s – so I flicked to 1/125s braced my right elbow in to my chest waited for the moment and pulled off three shots, continuous mode - this is the middle one.

I processed the RAW image via Photoshop 3 and used the Sharpening before JPEG conversion and also the Luminance Noise reduction. In RAW I also pulled the “exposure up” +2.7.

I was amazed at what I could get out of this HIGH ISO shot that was about 2½ to 3 stops underexposed on skin tone – I know that noise is atrocious at underexposed High ISO.

I worked the Blacks and the Curves in post production – I think that the background helped a lot and allowed me to darken the body/shirt of the man more than if he were front lit.

I am happy to accept there was luck in this one – but still, I think it is a good example of both the 5D and the 135L at an absolute limit – maybe the Photographer was at the limit too – as when I pulled these three shots I certainly was not confident that any one of them was safe in the bank . . . and I was quite lucid at the time as I had only sipped a little of that Scotch – but I choose the “perfect” Tv for the shot . . . and just hoped from there on in.

Shooting in Continuous Mode, in bursts of three gives some leverage – the middle one is usually the cleanest. If you try this method, you might like to stay above 1/100s – below 1/100s the vibration from the mirror slap, can bash you around a bit and cause some Shake induced Blur - this exact Tv limit depends upon the camera being used.

***

[*2] On the matter of Camera Format -

Camera Format does need to be taken into account apropos the Tv to arrest Subject Motion - but for most purposes we can treat an APS-C or DX or 4/thirds Digital SLR the same as a 135 format Film SLR or a Canon 5D or Nikon 700D. . . I just mention this minor technical addition for the "purity" of my contribution.


WW

Crikey! That question got me going - I now need another Scotch