Shutter Speeds

hello yet another problem im having trouble understanding the shutter speeds i understand what it does etc but not understanding why everyone and everywhere it says 'a shutter speed of 1/180' etc but on camera when i change shutter speed it just goes from 1 to 4000

4000 actually means 1/4000 of a second. 1 will mean 1 second. for 1/180 you're looking for a readout of 180.

It's also the fixed speed that some cameras use for flash (X mode on mine, I don't know about your model though)

Did your camera not come with a manual?

AH thankyou nass yes came with manual not very good though alot of jargon at the moment

Don't worry about it Emma, it's full of jargon. Just ask

Thankyou nass so if my studying is right a high shutter speed should be combined with a small aperture which in turn increases DOF which is good for macro and reversing it would be good for landscapes and best way to get control is using TAV mode

Small aperture (e.g., f/16) big depth of field, slow shutter speed (relatively)

Big aperture (e.g., f/1.4) shallow depth of field, fast shutter speed.

Choice of aperture depends on (a) how much DOF you want (do you want just the subject in focus and everything else blurry? Or everything sharp) and (b) whether the shutter speed is of importance or not (i.e., if hand-holding you'll need a faster shutter speed than if on a tripod, if photographing moving objects you'll probably want a faster shutter speed that photographing something static).

I, personally, use Av mode. I change the aperture to get the DoF I want whilst keeping half an eye on the shutter speed to make sure it isn't too slow. If I was photographing something moving where DoF is less of an issue than shutter speed (e.g., an air show) I would use Tv mode. I have never used TAv.

The only wrinkle in this scenario with digital is that it is possible to change ISO between shots too. So, if you wanted a good DoF but the shutter speed seemed to low to hand hold, you could up the ISO to get the settings you want.

I hope this helps!

K.

One thing at a time Emma

Say there's "X" amount of light falling on your subject. All else being equal, with just shutter speed and f stop variables, as you move UP in f stops (ie f8 to f 22), you'll need to move down in shutter speed to let the same amount of light in. Moving UP in f stops is called making the aperture smaller.

With smaller aperture you get more depth of field (DoF). The smaller the aperture (ie higher the f number), the more the DoF you get. Wide DoF is good for many things. Landscapes usually have a wide depth of field because you're usually taking a picture of a scene which has nearby bits and far away bits, and you want both in focus. You can be creative and just have some of that in focus but that's just a creative choice.

Macro is a right pig. DoF is unbelievably narrow in macro, a fraction of a mm for some of the stuff I've shot. For example see this broccoli shot. So you want as wide a DoF as possible, ergo as high a f stop that you can manage using your light sources.

I must admit I don't use modes that much. I use manual stuff. TAV, looking at the book, means you have 3 variables, ISO, aperture and shutter speed. And by the looks of the manual it adjusts the ISO based on your chosen settings.

So for round figures sake, imagine you're using ISO 100. Say the camera thinks you need 1/100 and f8, but you override this and absolutely insist you need f22 (for greater DoF) but the same shutter speed, then the camera will compensate by setting your ISO to 800 for you. Because ISO 800 is a 3 stop difference from ISO 100 (8 times more sensitive), to compensate for F22 which is a 3 stop difference from f8 the other way (1/8 as much light)

This is probably remarkably unclear and confusing... there are books on this subject that will explain it much better than me

Bottom line - macro, use as low an aperture as possible. DoF is the bane of your life

The best way of getting a feel for this is to pick up a film camera with an optical dof preview, and a lens with an aperture ring. Turn the aperture ring with the dof preview lever turned. You will see that the viewfinder image gets more in focus as the aperture gets smaller. It also gets a lot darker, therefore needing a longer exposure time.

why dont my aperture go down any more the F/4:

Probably cos that's the lenses max aperture - if its a zoom it may have a variable max aperture. This might be 3.5 at the wide end and 4.5 zoomed in. Or it could be a constant f4 lens. What does it say on the lens!

To take this one step further Emma:
Load up your P30 with a fast film (my choice was Fuji 400 ASA for many years) and work on adjusting the Aperture to get the Depth of Focus that you want. Do you want the background sharp, or artistically out of focus? Let the body work out what shutter speed to use. 400ASA will let you have a fair range of shutter speeds in the hand-held range. Then if you need a slower speed 'cos the sun has come out - you can hang a filter on the front. Start with the 50mm or the 135mm lenses - but not both until you have a handle on the technique.
This is the same sort of thing that Kris is advocating above.
Geoff