Silly beginner Qs again
Posted 09/02/2010 - 10:10 - Helpful Comment
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There are no silly questions, so ask away!
There is no need to have the lens wide open all the time - this would result in very little depth of field and less sharpness. Wide open is of limited use but might be required for some portraits or in very low light.
Medium apertures (f5.6 - f will give optimum quality and frankly most of my general shots are taken at f8. I only change this if I need either more DOF or a different shutter speed. Just make sure the shutter speed is fast enough to avoid shake.
Small apertures (f11 - f22 and beyond) will maximise DOF and are of use when very close (macro photography) or when everything needs to be in focus (landscapes maybe) but the smallest apertures are reserved for ovvassions that need them. Difrraction limits sharpness from f22 onwards.
That's a summary, but I'd suggest using f8 mostly unless the effect you want demands another f stop.
There is no need to have the lens wide open all the time - this would result in very little depth of field and less sharpness. Wide open is of limited use but might be required for some portraits or in very low light.
Medium apertures (f5.6 - f will give optimum quality and frankly most of my general shots are taken at f8. I only change this if I need either more DOF or a different shutter speed. Just make sure the shutter speed is fast enough to avoid shake.
Small apertures (f11 - f22 and beyond) will maximise DOF and are of use when very close (macro photography) or when everything needs to be in focus (landscapes maybe) but the smallest apertures are reserved for ovvassions that need them. Difrraction limits sharpness from f22 onwards.
That's a summary, but I'd suggest using f8 mostly unless the effect you want demands another f stop.
Best regards, John
Posted 09/02/2010 - 10:17
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OK - thanks - that's making good sense - that's the sort of answer I was hoping to get .
I love this K-x and I'm getting some great pics from it , and I'm surprising myself at times as to just how I'm improving.
I love this K-x and I'm getting some great pics from it , and I'm surprising myself at times as to just how I'm improving.
let the education continue
proud owner of a couple of cameras and a few bits and bobs
proud owner of a couple of cameras and a few bits and bobs
Posted 09/02/2010 - 10:51
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You need to ask yourself - do you want the subject isolated, with an out of focus foreground and background? (Wide aperture). Or do you want the whole view in focus? (Small aperture)
Or is there very low light, which would create camera shake (less than 1/15 hand held) or require too high an ISO?
Or is there very low light, which would create camera shake (less than 1/15 hand held) or require too high an ISO?
Posted 09/02/2010 - 11:37
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technoidiot wrote:
How do you decide when not to have your aperture wide open ?
EDIT: I missed the word "not" in the above. So please treat my following answer as an answer to the opposite question!...How do you decide when not to have your aperture wide open ?
When you want to minimise depth-of-field, or when you need to gather as much light as possible to have a fast enough shutter speed, or a low enough ISO, for your liking, to freeze motion (be it the subject's or camera shake).
Remember it's not just about the relationship between aperture and shutter speed, but the sensitivity (ISO) as well. The three things go together. Fortunately, you have a camera that performs exceptionally well at high ISO, so you don't have to worry about it as much as some of us!
You'll tend to use the lens wide open, or nearly so, more often with longer focal lengths (eg. 200mm) in overcast conditions, for example.
~Pete
Posted 09/02/2010 - 11:51
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We ain't touched on ISO yet - so with due deference I'll leave your answer alone for a while
I've enough to contend with thinking about shutter speed and aperture yet - that's still not coming without effort as yet
I've enough to contend with thinking about shutter speed and aperture yet - that's still not coming without effort as yet
let the education continue
proud owner of a couple of cameras and a few bits and bobs
proud owner of a couple of cameras and a few bits and bobs
Posted 09/02/2010 - 11:57
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Ok, no problem, just leave it on Auto ISO for now.
I think you're doing so well that the name "technoidiot" is inappropriate!
I think you're doing so well that the name "technoidiot" is inappropriate!
~Pete
Posted 09/02/2010 - 12:19
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I think the main problem for beginners with new and relatively high-tech DSLR cameras with numerous buttons for this, that, and whatever is the temptation to play with all these features without first grasping the basics. Well done for taking the trouble to learn.
To expose an image correctly, that is, to allow the correct amount of light to reach the sensor such that whites are not over-exposed and blacks are not under-exposed, there are only three variables that you can control.
Aperture - the size of the hole through which light enters the camera.
Shutter speed - the amount of time that light is allowed to enter the camera.
ISO - Equates to the speed at which the sensor collects the light allowed in by the other two variables.
When you can master these settings you'll have cracked 90% of the problems encountered with exposure. A light meter helps. The meter in your camera measures only reflected light, a hand-held meter is more useful as it can measure incident light.
Next comes the creative bit, the remaining 10% which will probably take you the rest of your photographic career to explore. A creative photographer learns how to use these 3 variables in combination to capture an image. Wider aperture gives shallower depth of field, shutter speed selection will determine whether you have any motion blur in images of moving subjects etc. etc.
Keep practising, you'll get there.
To expose an image correctly, that is, to allow the correct amount of light to reach the sensor such that whites are not over-exposed and blacks are not under-exposed, there are only three variables that you can control.
Aperture - the size of the hole through which light enters the camera.
Shutter speed - the amount of time that light is allowed to enter the camera.
ISO - Equates to the speed at which the sensor collects the light allowed in by the other two variables.
When you can master these settings you'll have cracked 90% of the problems encountered with exposure. A light meter helps. The meter in your camera measures only reflected light, a hand-held meter is more useful as it can measure incident light.
Next comes the creative bit, the remaining 10% which will probably take you the rest of your photographic career to explore. A creative photographer learns how to use these 3 variables in combination to capture an image. Wider aperture gives shallower depth of field, shutter speed selection will determine whether you have any motion blur in images of moving subjects etc. etc.
Keep practising, you'll get there.
Peter E Smith - flickr Photostream
Posted 09/02/2010 - 12:22
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I appreciate the question has been answered already, but hopefully it helps to have it put in a few different ways...
However, you may need the lens wide open, or near wide open, to get a fast enough shutter speed (or to a avoid grainy image) to freeze motion when the light is dimmer than ideal. You'll need to do this more often with longer focal lengths to avoid camera shake.
technoidiot wrote:
How do you decide when not to have your aperture wide open ?
Stop down when you want more depth-of-field, or more quality from your lens, or when the light is so strong that you have to.How do you decide when not to have your aperture wide open ?
However, you may need the lens wide open, or near wide open, to get a fast enough shutter speed (or to a avoid grainy image) to freeze motion when the light is dimmer than ideal. You'll need to do this more often with longer focal lengths to avoid camera shake.
~Pete
Posted 09/02/2010 - 13:10
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technoidiot wrote:
How do you decide when not to have your aperture wide open ?
When I was first starting out (I almost put when I was learning, but of course I'm still doing that! I hope!) I formulated this question slightly differently. My formulation wasHow do you decide when not to have your aperture wide open ?
[quote="Mini Mongoose"] How do you decide when not to have your aperture on f/8?[/quote]Lenses differ of course, but most lenses are at their best in terms of overall image quality at or near f/8. To this day, f/8, aperture priority remains my default "walking around" setting. I only change from this if I have an artistic or practical reason to do so.
Someone above said leave it on Auto ISO for now, I would disagree with this slightly. If you want to ignore ISO until your ready to understand it (a wise decision!) I would set the camera on one fixed ISO and leave it there. I suggest setting ISO 400 for now, as this will give you versitility in your subjects without having to worry about changing ISO until you're ready. If you're already fixed on one ISO and leaving it there, don't change it, I just suggested 400 in case you are on Auto and don't know where to put it.
The reason I say this is that you are currently struggling (as we all did once!) with aperture and shutter speed. You want to keep everything else static while you learn the relationship between aperture and shutter. If you're on Auto ISO the camera will fiddle with the ISO for you, which could lead to some confusing results.
you don't have to be mad to post here
but it does help
but it does help
Posted 09/02/2010 - 13:19
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I'm tending to use Av or Tv only at present - so the camera deals with ISO for me - and frankly I'm happy at present to leave it like that
let the education continue
proud owner of a couple of cameras and a few bits and bobs
proud owner of a couple of cameras and a few bits and bobs
Posted 09/02/2010 - 13:26
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You can set the ISO manually for use with Av if you wish, though I suggest leaving ISO on Auto for now if you shoot in a variety of conditions.
~Pete
Posted 09/02/2010 - 14:34
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whatever you feel comfortable with is fine, just be aware that with the camera on auto ISO opening up the lens by one stop wont necessarily boost the shutter speed by a corresponding stop and vice versa.
I think the relationship between Aperture and Shutter is easier to see with a constant ISO.
That said if I recall correctly the auto ISO biases quite heavily towards the low settings anyway, so for the most part it shouldn't be an issue.
I think the relationship between Aperture and Shutter is easier to see with a constant ISO.
That said if I recall correctly the auto ISO biases quite heavily towards the low settings anyway, so for the most part it shouldn't be an issue.
you don't have to be mad to post here
but it does help
but it does help
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4141 posts
16 years
Glasgow
I'm happy enough now stating to make decisions rather than leaving the camera to do it for me
BUT
How do you decide when not to have your aperture wide open ? I realise the relationship between aperture and shutter speed but just how do you decide which fstop you should be using ? I'm sure this is something that comes with experience but I'd like to make that decision NOW - looking at my recent pics they are all with the aperture as wide open as I can get it and I'm sure that I should be starting to shut it down a bit
proud owner of a couple of cameras and a few bits and bobs