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I have a book and i have the internet and yet i still need help???
Okay very beginner questions. I have read a ton of stuff, but I cant seem to get the whole picture (no pun intended) on fstops, iso, shutter speed(i understand shutter speed, but cant really use it to my advantage I dont think)....

I take a picture with a setting, then I retake the picture with the iso changed, and lets say it is darker, then I change fstop, and it is also darker..??? Maybe not darker, but you know what I mean..i cant seem to figure out what all teh fine adjustments do to my pictures??!!.

I know that somehow they all kind of relate to each other in a way but what exactly will a f5.6 do that a f24 wont... ISO 200 or ISO 1600??? What exactly do they do or are they supposed to do..

If any of this makes sense, feel free to give your .02$..

I also like picture comparisons if ppl know where I can see some that would be so helpful..

Thanks..

Comments (9)

Very simply:.

Fstop is how big the hole is in your lens. How much light is getting in. The lower the Fstop the more light. F5.6 will let in much more light than F24. But it won't be as controlled..

Think of it like pouring paint in a bucket. You can do it without a funnel and you will get the paint in much quicker - but it will probably splash up on the sides. A funnel will take longer but will be much more controlled..

With FStops - lower will make some things out of focus (on purpose). Like when you take a portrait - the person is in focus but the background is blurry..

When you take a landscape, you want everything in focus - so you will use a "funnel" - a larger FStop. It will take longer for the light to reach the sensor, but everything will be in focus..

ISO is the sensativity of the camera. The lower the ISO the less sensative the the camera is to light. When you are shooting in dark situations, you want the camera to be more sensative so that the shutter doesn't have to stay open any longer than necessary. But on bright sunny days, you can have a lower ISO, because the light is bright enough to expose the sensor without any problem..

You have to think of the three aspects as a triangle. If you change the shutter speed, then you need to adjust either ISO or FStop to retain the correct exposure. This is true for all three aspects, ISO, FStop and Shutter..

Hope this helps...

Comment #1

Heyfredyourhat wrote:.

Okay very beginner questions. I have read a ton of stuff, but I cantseem to get the whole picture (no pun intended) on fstops, iso,shutter speed(i understand shutter speed, but cant really use it tomy advantage I dont think)....

Imagine that taking your photograph is like filling a glass of water from the tap - you have to get enough light onto the sensor or film plane to expose the image there. When you take a photograph, the iris blades in the lens open up into a hole to let light through to hit the sensor..

The aperture is the size of that hole, the shutter speed is how long it stays open for. So like filling a glass with water, the harder you run the tap, the quicker the glass is filled. So the bigger the hole in the lens aperture, the less time it has to stay open to let the same amount of light through. So to expose an image there are many permutations of aperture and shutter speed that will all expose an image correctly. Which combination is right for the shot will depend other creative factors. If you double the area of the hole (i.e.

So there is a direct correlation between the two. 1/100 @ f2.8 is the same exposure as 1/50 @ f4 and 1/25 @ f5.6..

ISO is the third element in your exposure triangle. This is the sensitivity of the sensor to the light hitting it - if you increase it, you need less time or aperture for the same exposure..

I take a picture with a setting, then I retake the picture with theiso changed, and lets say it is darker, then I change fstop, and itis also darker..??? Maybe not darker, but you know what I mean..icant seem to figure out what all teh fine adjustments do to mypictures??!!.

If you're in some sort of auto mode and change elements, the camera will change the remaining elements to compensate so that the image is still correctly exposed. If you adjust ISO, aperture or shutter speed and take a series of shots with a variety of settings, exposure-wise they should all be just the same. Other factors will change like depth of field and potential noise in the image etc., but they should all be equally dark or light..

I know that somehow they all kind of relate to each other in a waybut what exactly will a f5.6 do that a f24 wont... ISO 200 or ISO1600??? What exactly do they do or are they supposed to do..

The f number is your aperture - the smaller the number, the bigger the hole - the easiest way to remember this is to keep in mind the correct way to express it which is as a fraction f1/4 or f1/16 - as you can see, 1/4 is a bigger number than 1/16. The bigger it is (small number) the more light that can get through it - so these are best for low light situations. The downside is that the lens tends not to be it's sharpest here and you have a shallow depth of field. Most lenses are sweetest in the mid-range apertures they're capable of. For compacts that usually something like f5 or f5.6 and for DSLR lenses more like f8 or f11. I can't think there can be many situations were f22 would be recommended.

The only time that might be useful is for DSLR lenses with macro work where DOF is miniscule..

ISO - I would recommend that you always use the lowest one that will let you get the shot within your comfort zones on the other elements. If the light available suggests a shutter speed of 1/30 at 100ISO and you know that you can't keep still that slow, increase the ISO until you get a shutter speed that you can hold still. So taking it to 200 ISO would need 1/60, 400ISO would need 1/125, 800ISO = 1/250 etc..

The correlation between the three elements is measured in units called stops (there are half and third stops between them too) and the factor of change is halving and doubling. If you increase one element by a stop, you need to halve one of the others for the same resulting exposure - or both of them by a half stop each. So every adjustment of either factor requires or indicates an equal adjustment in one of the others..

So many photos, so little time.http://www.peekaboo.me.uk - general portfolio & tutorialshttp://www.boo-photos.co.uk - live music portfoliohttp://imageevent.com/boophotos/ - most recent images.

Please do not amend and re-post my images unless specifically requested or given permission to do so...

Comment #2

That's a wide open question with lots of answers. I know you said you have done a lot of studying but you may try one more book. I believe it is called Understanding Exposure and a lot of people swear by it. I wish I could remember if that is the exact title or the author but maybe someone else will remember it and pass on the info..

Basics:.

F stop = how much light the lens can pass, effects DOF also. A relationship of the aperture and focal length..

Shutter speed = how long the shutter is open, again how much light is let in. Effect the ability to stop action or create blur for effect..

ISO = standard for sensitivity of the media. Can be changed in DSLR's by increasing gain of amplifier. Too much amplification can lead to noise..

Like I said real basic answers.Doug.

Http://douginoviedo.smugmug.com/..

Comment #3

Hmm it makes sense now..

So for all you pros out there or not even pros but just regular camera ppl, can you see your pose and know what to set the camera at to get the perfect shot. Or is it alot of multiple shots with fine adjusments......

Comment #4

From Bill Huber of the Olympus Talk Forum.Click on thumbnails for larger view.http://www.pbase.com/otfchallenge/the_basicsJoe B..

Best wishes.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

Anything's possible if you don't know what you're talking about...

Comment #5

Heyfredyourhat wrote:.

So for all you pros out there or not even pros but just regularcamera ppl, can you see your pose and know what to set the camera atto get the perfect shot. Or is it alot of multiple shots with fineadjusments.....

Depending on the scene you're presented with and the ideas you have for taking it, basic settings will automatically present themselves and give you a starting point. From there, you would touch the shutter button to see what exposure the camera presented you with, possibly make some adjustments, then take the shot and review. I would rarely need to take multiple shots to get it right. Your first choice would be what mode to put the camera in and what metering mode would be best for that scene..

For example, if I were taking a live music shot - something I do a lot of - I'm starting off with very little light - so I'd already be at 1600ISO and the widest aperture the lens would allow - to get the maximum amount of light in - so I'd set the camera in Aperture Priority mode to set the aperture as a non-variable. And spot metering as the scene will have dark surroundings and brightness directly on the performer..

I'd then touch the shutter button with the lens on the performers face and see what shutter speed it gave me, if that was within my comfort zone for the focal length, I'd lock focus on his face, frame, wait my moment and then take the shot. Shots like this are a one shot deal and I don't have the luxury of multiple attempts. Constantly review and if your shots aren't coming out how you want, then you need to change something. This with my 20D DSLR a couple of days ago, 1/60 F2.8 1600ISO 28mm:.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

With a landscape shot, you're going to have more light and your criteria is sufficient DOF and not over-exposing the sky. So I'd start at 200ISO (my personal preference for maximum dynamic range) and f8 or f11 for DOF and average metering. I'd compose and frame, pre-focus where I chose and again look at the shutter speed etc. making any necessary adjustments. For landscapes focus is perhaps more critical, so I'd usually pre-focus where I calculated would be a good place, put the lens into manual focus, check with the focus confirmation dot that I'd got the DOF I needed, then frame and take the shot..

1/800 F8.0 200ISO 12mm:.

Image control:Zoom outZoom 100%Zoom inExpand AllOpen in new window.

So you see how the scene will automatically present a starting point depending initially on how much light you have, but also the DOF you require, the focal length and whether you're hand-holding or have a tripod etc. etc..

So many photos, so little time.http://www.peekaboo.me.uk - general portfolio & tutorialshttp://www.boo-photos.co.uk - live music portfoliohttp://imageevent.com/boophotos/ - most recent images.

Please do not amend and re-post my images unless specifically requested or given permission to do so...

Comment #6

Having a triangle but only adjusting two out of three elements can be difficult. It may help your understanding to remember that, until digital, there were only really two variables - aperture and shutter speed - change one and you (or the camera) would need to change the other..

With film you were stuck with the same ISO speed for the entire 36 shot roll. Most people would use a low film speed unless they had to go higher. Just adopt the same approach with digital. Stick the camera on ISO 100 and adjust aperture and shutter. If you cannot get the result you want up the ISO..

You already have one example of when high ISO is necessary - in low available light. A different example might be a sports shot in poor daylight. To freeze the action you need a high shutter speed - say 1/1000 but you might find your lens has bottomed out on aperture at say f/5.6 and your shutter speed is still only 1/250th. So up the ISO from 100 to 400. That will give you 1/1000th..

Generally you should keep the ISO as low as possible to avoid a grainy image..

It is best to take control of one parameter using either shutter or aperture priority mode leaving the camera to make consequential adjustments to the other..

But you should always take account of both before pressing the shutter. - An example - You are taking a photo of some rapids. You have the camera set on f/8 to give you enough depth of field so that eveything you want is in focus but that gives you a shutter speed of say 1/150th. At that speed you will begin to freeze the action of the water movement. You will get a better picture at say 1/30th (provided you are on a tripod that is!). So if you up the aperture to f/16 you know that the shutter speed wil reduce to around 1/30th and the white water will look blurred to give the impression you might want.



Hope that helps.

Chris Elliott.

*Nikon* D Eighty + Fifty - Other equipment in Profile.

Http://PlacidoD.Zenfolio.com/..

Comment #7

I believe in simple answers. The simplest I could think of is that you can't read? .

Heyfredyourhat wrote:.

Okay very beginner questions. I have read a ton of stuff, but I cantseem to get the whole picture (no pun intended) on fstops, iso,shutter speed(i understand shutter speed, but cant really use it tomy advantage I dont think)....

I take a picture with a setting, then I retake the picture with theiso changed, and lets say it is darker, then I change fstop, and itis also darker..??? Maybe not darker, but you know what I mean..icant seem to figure out what all teh fine adjustments do to mypictures??!!.

Digital is free. Play more...read less?.

I know that somehow they all kind of relate to each other in a waybut what exactly will a f5.6 do that a f24 wont... ISO 200 or ISO1600??? What exactly do they do or are they supposed to do..

You can and should choose a sensitivity setting before you start. Just guestimate the available light and pick an appropriate ISO setting. Experience will get you really close. If, after choosing a sensitivity, your other two settings are not quite right (aperture too wide = low DOF or exposure time too slow = motion blur) then iterate and choose a different ISO sensitivity..

The other two are more difficult. You need to learn not what their PRIMARY effect is (ie, what they contribute to proper exposure), but rather what SECONDARY effects they have. Exposure speed's secondary effect is controlling motion blur. Aperture's secondary effects are controlling DOF and lens abberations..

Charlie DavisNikon 5700 & Sony R1HomePage: http://www.1derful.infoBridge Blog: http://www.here-ugo.com/BridgeBlog/..

Comment #8

Try Bryan Peterson's "understanding exposure". He explains the relationship between iso (film speed), shutter speed, and aperture very well..

Mike..

Comment #9

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