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Photography - what do these all mean?
fat controller
Posts: 13,757 Forum Member
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I am trying to get a better understanding of photography, and the terms relating to it (mainly so that I don't look thick when Mrs C gets her new camera next week). Please be gentle, because I really am not 'getting it' at all.
First question - ISO numbers. Now, back in the days of yore when cameras took films, I seem to recall that these numbers related to the speed of the film, as in how quickly it would react to the light coming in through the shutter?? As digital cameras don't have any film, what does the ISO number mean?
1/160 sec or 1/320 sec etc - is this the shutter speed (as in the length of time that the shutter is open for)?
f/5.6, f/11 or f/8 etc - what does this mean?
28mm, 62mm, 84mm - I'm guessing that this is the aperture setting? Does this basically mean the size of the hole in the shutter when it opens?
Thanks in advance
First question - ISO numbers. Now, back in the days of yore when cameras took films, I seem to recall that these numbers related to the speed of the film, as in how quickly it would react to the light coming in through the shutter?? As digital cameras don't have any film, what does the ISO number mean?
1/160 sec or 1/320 sec etc - is this the shutter speed (as in the length of time that the shutter is open for)?
f/5.6, f/11 or f/8 etc - what does this mean?
28mm, 62mm, 84mm - I'm guessing that this is the aperture setting? Does this basically mean the size of the hole in the shutter when it opens?
Thanks in advance
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28mm etc are the focal length of the lens. The shorter the focal length the more "wide angle" the view; as the length increases the lens becomes more of a portrait lens, then a telephoto (brings objects nearer). If the camera has a zoom lens it will be have a variable focal length so you can use the same lens to take landscapes, portraits and make faraway objects look closer and larger.
f5.6 etc are the aperture settings. The lower the number the more light the lens lets in. Conversely, the lower the number the less depth of field. In other words, things are in focus over a shorter range, so a nearby object will be in focus but a faraway one will be blurred (or vice versa). If you want a sharp picture you may prefer to use a higher aperture setting but less light will mean you need a lower shutter speed.
So then 1/125 etc are the shutter speeds. The shorter the time, the less light is allowed in so in bright light you might want to use a shorter exposure and in poor light you need a longer one. But don't forget that the longer the shutter is open, the more noticeable camera shake will be. I think anything under 1/125 is risky if you want to eliminate camera shake, particularly using a zoom lens.
The ISO is an indication of how sensitive the "film" is to light so in a digital camera it determines how much light is needed to take a good picture. Because there are two factors affecting the amount of light - the shutter speed and the aperture - for every ISO there will be a number of speed and aperture combinations. Being able to vary the ISO means you can select the combination of shutter speed and aperture that works for the picture you want to take: higher ISO for bad light or to avoid camera shake, maybe; lower ISO to allow more control over aperture in good light.
Hope that makes some sense!
ISO is the films sensitivity to light.
The numbers 1/60secs etc are the shutter speed so 1/4 means the shutter lets in light for 4 seconds, thats how you get this effect [url] http://www.danheller.com/images/UnitedStates/Illinois/Chicago/Nite/light-streaks-1-big.jpg[/url]
explains--->http://www.homephotog.com/tutorials/shutter-speed.shtml
The mm numbers are lens focal lengths, the higher the number, the longer zoomed in effect the lens gives, the lower the number the wider, more content you can get in your shot, fisheye being the extreme at around 8mm, resulting in distorted curved perspective like this
>http://www.google.co.uk/imgres?imgurl=http://www.photographytips.com.au/images/fisheye-lenses-photos31.jpg&imgrefurl=http://www.photographytips.com.au/fisheye-lenses-expand-your-photo-skills/&usg=__kXlb-wyN456ZGYjHybKYObmMjjQ=&h=806&w=860&sz=139&hl=en&start=0&zoom=1&tbnid=1uJoK2kddH2iqM:&tbnh=120&tbnw=127&prev=/images%3Fq%3Dfishe%2Beye%2Blens%26um%3D1%26hl%3Den%26safe%3Doff%26sa%3DN%26biw%3D1366%26bih%3D559%26tbs%3Disch:1&um=1&itbs=1&iact=hc&vpx=546&vpy=232&dur=1882&hovh=217&hovw=232&tx=119&ty=101&ei=2CUaTaWeD4LOhAfqsdi3Dg&oei=2CUaTaWeD4LOhAfqsdi3Dg&esq=1&page=1&ndsp=24&ved=1t:429,r:11,s:0
There's alot more to it, so check out youtube.
I read something in one of the reviews for the camera about a bulb setting or bulb feature for extended shutter openings of up to four minutes (I assume to allow for arty-farty images taken at night with all the solid lines from cars passing and stuff) - does that mean it needs some kind of flash bulb plugged into it, or is it just the name for a setting on the camera?
I think "bulb" refers to the setting on older film cameras marked "B" which effectively kept the shutter open as long as you wanted. You wouldn't use a flash bulb to photograph passing cars etc, but you would need a tripod to prevent the camera moving whilst the shutter was open.
Thanks for the links
Once Mrs C gets her new camera, I am going to nick her old one to teach myself a bit more.
Must admit I never even considered checking youtube.
OK, I'll do this in bits
You're right about film, ISO 50 would be slow, high resolution film, 400 would be high sensitivity, more grainy. The electronic sensor has a fixed light sensitivity but the calculated exposure would be worked out as if it was adjustable. The upshot is that you can simulate fast film for low-light or short exposure situations but doing so degrades the signal-to-noise of the image as less light falls on each pixel during the exposure.
Yes - short times for stopping moving subjects, longer times for low light or to allow small apertures to get bigger depth-of-field.
This is the aperture, the bigger the number under the "f", the smaller the aperture allowing less light in but increases the focus depth. Larger apertures can be used to isolate the subject from the background.
This is the focal length of the lens - small number is wide angle, large number telephoto. For a digital camera, 40mm is about "standard", equivalent to normal sight.
This - it dates back to old fashioned flash bulbs when you opened the shutter then triggered the flash. And you're right about it's use!
You really do need to read up in more depth than can be put into a post like this as all the factors like shutter speed and aperture are interlinked and you have to make compromises.
Don't shoot into the sun, try and keep heads in the frame and take lots of pics and be brutal when deleting the crap ones. Dont use the camera zoom too much (as you will loose quality) and you can crop the picture better if you have a choice of what you want in the composition.
If you got a decent canon slr then it's still automatic-everything so don't worry about iso's etc unless you want arty-farty effects, or you think you know better than the on-board computer that reads the light settings, and works out the auto focus by shining an infra-red beam and calcultining to the cm how far they are.
If you do want arty farty effects, then look at post photography software like adobe lightroom. There is nothing you can't do with that, even starting from a crappy snap which was set to the wrong iso and fstop. Good luck, and tell Mrc C to enjoy it and snap plenty.
Oh! and spare memory cards are a good idea and a supply of rechargeable batteries are a must.
I see - had never heard of the setting before, but then the cameras I used to play with were bog standard point and shoot jobs. We've got a good tripod, although to date it has seldom been used.
I will have the old one (Panasonic DMC-FZ50) to play with and to learn with, which has a lot of the manual settings available on it for me to try.
varialectio - thanks for the explanations
That's a fully automatic camera. Just set it to auto and click away. There is nothing your wife can set that the camera hasn't already worked out. In the old days of manual photography, you had to set everything, and you needed light meters, and a good eye for focus and you had to load the appropriate fugi film iso 100 to 400 (and slide film if you wanted any higher). That's all changed now. You have about 12MP that's enough to do most anything.
When your wife trades up again look at the canon 550D best piece of kit out there, (for the money) for not much more than the Lumix and the EOS 550D has 18MP. It's pictures are amazing and comparable with pro cameras costing thousands. Canon make the best top end cameras, Nikon are second and the rest play catchup.
If the only way you are going to get the pic is using iso 800 - 1600 then get the pic. Noise can be fixed in Adobe Lightroom, but Lightroom can't invent the picture.
Most pros, set to auto, let the on board computer do it's job, hold the camera firmly to avoid shake, and click plenty.
Learning by heart how to get to the cameras functions and menus quickly will be the best investment of time, next is pushing the delete button while previewing the pic in the on-board lcd screen and deleting when pic is obviously crap, or she will have thousands of pics to download and go though cluttering up her memory card, or worst still her hard drive.
Have a read of Bryan Peterson's Understanding Exposure!
It really is a helpful book and should help make things clearer
http://camerasim.com/camera-simulator.html
http://www.photonhead.com/simcam/shutteraperture.php
I think you'll like the 1st one.;)
The on board computer will give you an average shot. To be creative, use the creative(manual) modes.
it is an excellent piece of kit, but megapixel counts are marketing bullshit and have little relevance to picture quality.
Having an SLR and only shooting in automatic is like owning a Ferrari and only using it to pop down to the shops. However good the camera is, it can't mind read what you want to show in the shot.
I beg your pardon?!?
Nikon actually has better high ISO performance across most of they range (compared to eq. canons.)!
And don't give the op bad info inferring more MP is better....
^this!!!!
Also, if you want to learna little about photography buy Brian Peterson's 'understanding exposure' book.
Actually, there are three factors affecting the amount of light.
Shutter speed, aperture, and available light.
Cracking links - both bookmarked! Thank you
She will, I am sure, but I am an independent little sod and to be honest I think it frustrates her a bit trying to explain it to me as she takes to it like a duck to water.
We looked at the Canon 550D (it was the only other camera on the shortlist at the end up), but the Panasonic won based on the fact that it seemed to be such a good all-rounder, and the fact that our FZ50 has been such a reliable beast (and it has been truly hammered).
Higher ISO settings (400+) can also result in a very noisy picture on a digital camera (especially small compacts)
There is a crude intercative web page showing the effect of ISO settings on a couple of cameras
http://www.dpreview.com/reviews/q42010highendcompactgroup/page15.asp
the www.dpreview.com site may have an indepth review of the camera you are buying (or one similar from the same manufacturer)
Many of terms used with a digital camera are derived from a 35mm film camera.
I've recently bought an SLR and went to various shops for advice before settling on a purchase, and all of them, without exception, said Nikon was the best brand.
just lol.
I reckon there was a Nikon promotion when you asked the shops trying to sell you cameras which brand is best. e.g.Take a look at any sports event to see what brand lenses dominate the photo pit for sports photography.
http://www.newstalk.ie/wp-content/files/2009/11/sportsphotos.jpg