Auto Vs Manual control

[joescrivens]

Personally i would'nt want to shoot a 100mm lens at such low shutter speeds so if i needed natural light i would have stuck the camera on a tripod and used AV, or used flash

how would you cope with a 500mm lens shooting birds outside on a sunny cloudy day with variable light with all different colored birds trying to catch them as they land on a perch before jumping onto a feeder ?

you're kind of avoiding the question there. The point is the best settings for that shot given the parameters I had - no flash, no tripod and a 100m lens is the one I got manually - how would you make the camera make that shot in Av?

 

[fastworldimages]

However, I still think it's better for beginners to shoot manual as it imparts a greater understanding of the relationship between shutter-speed and aperture settings (and ISO) than any of the auto modes.

I concur, i allways try to get my friends to do this, ok at first it doesnt give good results but just how long can one go on using P or full Auto modes for and say they really understand setting up their camera.

 

[joescrivens]

Click; check; need to shoot another; oops, there goes the opportunity over the horizon! What do you learn from that? Manual doesn't work all the time - nothing DOES work all the time.

but that doesn't happen with manual if you use it properly, to be honest if thats what is happening then I can't see how using exposure compensation would be any different.

my mind goes like this as an example

what lens do I have attached - 100mm
Is the subject moving - yes
Do I have IS - no
ok so shutter at a minimum of 100mm
How big is the subject, how much dof do i want - would give me a variable answer, lets say it was a portrait of one person - f4
How much light is there - not a lot
What ISO did I use last time I shot a scene like this - around 600

outcome - shutter 100, f4, ISO 800 (just in case)

bang, shot nailed

 

[trencheel303]

He thinks like me! And all of that in a second or two, while configuring the camera.

 

[Dogfish_magnet]

you're kind of avoiding the question there. The point is the best settings for that shot given the parameters I had - no flash, no tripod and a 100m lens is the one I got manually - how would you make the camera make that shot in Av?

Simply set the camera to AV then up the ISO until i had a shutter speed i was comfortable with.....simples

 

[joescrivens]

Simply set the camera to AV then up the ISO until i had a shutter speed i was comfortable with.....simples

then you would end up with an iso higher than the optimum for the scene. when i picked 1000 it gave me a shutter of 1/20 i had to get it up to 2000 before it gave a correct shutter. but on manual i chose 1000 and 1/50. in av the camera never got to the optimum settings

 

[dfawkes]

Personally I don't see the point in buying a DSLR and not going straight to manual, you learn so much so quickly

I never understand this view though it's one stated quite often: it pretty much amounts to "if you're not using a DSLR in manual, you're using it wrong".

Anyone that uses Manual and uses the meter in the camera to determine the exposure is doing absolutely the same as if it was in e.g. Av. With Manual, set two of the variables you want, then pick the other to put the needle where you want it.

In Av/Tv, set the two variables you want, put the needle where you want it and let the camera determine the other variable. Exact same outcome, different approaches.

If one was to use proper "Auto" all the time where the camera chooses all variables, and whether to use flash, etc then clearly there's a "why bother" argument. But with semi-auto modes such as Av/Tv you still have total creative control and therefore should be allowed to use an SLR.

And being semi-auto doesn't mean that you don't understand the relationship betwen aperture-shutter speed-ISO (though manual may help you learn it faster), just that rather than having to change both aperture and shutter speed from f/11 at 1/60 to f/5.6 at 1/250, I can change from f/11 to f/5.6 and the camera will change the shutter speed accordingly. It's lazier, but it doesn't indicate a lack of skill or understanding.

Edit: I meant to finish by saying - if it's not obvious by now - that both approaches are equally valid, and I'll pick the one that suits the current situation best - most of the time Av does that just fine.

 

[dfawkes]

then you would end up with an iso higher than the optimum for the scene. when i picked 1000 it gave me a shutter of 1/20 i had to get it up to 2000 before it gave a correct shutter. but on manual i chose 1000 and 1/50. in av the camera never got to the optimum settings

Don't quite get what you're saying here: ISO 1000 @ 1/20 and ISO 1000 @ 1/50 are a stop apart so in Manual you must have been exposing by a stop less. If that was the effect you wanted, then setting ISO 1000 and EC-1 would've given you a 1/50 shutter?

 

[Dogfish_magnet]

then you would end up with an iso higher than the optimum for the scene. when i picked 1000 it gave me a shutter of 1/20 i had to get it up to 2000 before it gave a correct shutter. but on manual i chose 1000 and 1/50. in av the camera never got to the optimum settings

No - the camera gave you the optimum settings to get a correctly exposed image, you have then decided to under expose the image to use the settings you want, if this was a image with lots of shadow detail you would have lost the detail in the shadows by under exposing, you would then use PP to bring back the shadow detail and also introduce loads of noise by doing so - so you may as well used the higher iso to start with.

 

[mrtoad]

auto is auto

manual is manual

there are quite a lot of viable intermediate usage there

P AV TV +/- exposure control

auto does funny things with iso and doesnt allow the flash to be controlled...built in flash as i have on my cameras

my personal settings are P with iso set and always looking to use +/- along with the spot metering readings i use to decide on exposure after doing some scan..maybe auto does this but i like to be 'in charge'....although the results teach me some lessons each time
mainly that there is no real accurate exposure for a shot to suit all purposes

 

[joescrivens]

No - the camera gave you the optimum settings to get a correctly exposed image, you have then decided to under expose the image to use the settings you want, if this was a image with lots of shadow detail you would have lost the detail in the shadows by under exposing, you would then use PP to bring back the shadow detail and also introduce loads of noise by doing so - so you may as well used the higher iso to start with.

you're kidding right? look at the three images and tell me which is the best of the three. 1 has too much noise, 2 is as exposed and sharp as 1 but with less noise, 3 is blurry and unusable

dont you see that in this exampl manual provided the best results?

 

[mrtoad]

the best results arent given by manual but the discrete settings on the camera
they can be aquired in any mode...almost

 

[Dogfish_magnet]

you're kidding right? look at the three images and tell me which is the best of the three. 1 has too much noise, 2 is as exposed and sharp as 1 but with less noise, 3 is blurry and unusable

dont you see that in this exampl manual provided the best results?

TBH - its a picture of a lens cap with horrendous CA in all the crops - they would all go in the bin, go try something with a wide dynamic range and shadow detail. the last one is the only one with the correct exposure.

 

[HoppyUK]

I never understand this view though it's one stated quite often: it pretty much amounts to "if you're not using a DSLR in manual, you're using it wrong".

<snip>

I agree.

There is a view amongst many newcomers that using manual, and trixy stuff like spot or incident light readings, somehow gives you a fundamentally better result.

It does not. Just different ways of doing the same thing, and for the most part dating back to film when we needed all the help we could get. That doesn't apply now.

I also don't think that manual is the place for newcomers at all. Too many post on here prove that, until you have at least a basic understanding of what's going on (and we all have to start somewhere) then manual can get you into all sorts of trouble.

P mode will always get you a result. Then check the Exif and see what the camera is doing. Only when you've got a good grasp of that is there any point in using manual, and even then it's more a matter of preference than anything else.

 

[dfawkes]

you're kidding right? look at the three images and tell me which is the best of the three. 1 has too much noise, 2 is as exposed and sharp as 1 but with less noise, 3 is blurry and unusable

dont you see that in this exampl manual provided the best results?

Manual only provided the best result because you've underexposed (relative to 3rd shot) to get a faster shutter speed. Av is trying to get an accurate exposure so picks a slower shutter speed. To get the equivalent in Av you would dial -1EC. Manual doesn't magically add more light

 

[joescrivens]

TBH - its a picture of a lens cap with horrendous CA in all the crops - they would all go in the bin, go try something with a wide dynamic range and shadow detail. the last one is the only one with the correct exposure.

You're far to concerned with being right than discussing the point, the CA has nothing to do with AV or manual mode so I don't even know why you are bringing that up. For some reason you can't admit that in the instance I showed you using manual provided the best results.

With regard to the camera picking the best exposure for the 3rd shot, why didn't it pick that exposure for the first? It had total control over the shutter and the ISO yet it also underexposed the image, how do you explain that? My manual image I was just copying the exposure of what the camera had chosen in the 1st to show that I could get a better result at that exposure.

Here's another example then, I tried to add some light and shadow detail to make the shot a bit more complex, here are the results:

Av mode with aperture set to 4, camera chose a shutter speed of 1/125 and ISO 2000

100%

I knew for a fact I could get a slower shutter and reduce the ISO to save on noise so I went with shutter of 1/20 and ISO 320

100%

Is that a better result? I think so, it has the same level of exposure as what the camera picked and yet a lot less noise, it's also as sharp. Do you agree or disagree?

Lastly I let the camera pick the shutter for ISO 320 to see if it would pick the right shutter for me as I did and it picked a shutter of 1/10 and I got this

100%

so again, didn't I get the best result using manual?

 

[joescrivens]

Manual only provided the best result because you've underexposed (relative to 3rd shot) to get a faster shutter speed. Av is trying to get an accurate exposure so picks a slower shutter speed. To get the equivalent in Av you would dial -1EC. Manual doesn't magically add more light

absolutely, and this is kind of my point. The camera will always just go with the best exposure and that isn't always the right thing to do. The humans eye and brain is a lot more complex than a chip in a camera and so we know a little more about the scene, my brain could tell that in the instance I had, the correct exposure was going to give too slow a shutter speed or too much noise, none of the results with that combination of light and lenses was going to produce a perfect result but I can decide whats the best of a bad situation and get the better shot, the camera can't make that decision and I think that is where manual is a step above.

as an aside, why did the camera not get the right exposure on shot 1 when it had control of both iso and shutter?

 

[dfawkes]

The humans eye and brain is a lot more complex than a chip in a camera and so we know a little more about the scene, my brain could tell that in the instance I had, the correct exposure was going to give too slow a shutter speed or too much noise

Yep, spot on - a camera is never (with current technology ) going to know what the correct exposure is - in fact it's definition of correct is an average of 18% gray (or I've read that camera meters go off 12%?). And it's not going to take into account the various factors that you mention automatically - it's just picking a shutter speed based on what it thinks a correct exposure is, and the user needs to tell it, using EC, how far the correct exposure is from what it expects (put another way, how wrong the camera is ).

I totally take your point that if you use Av and shoot whatever the camera thinks is best, then Manual is "better" - but the equivalent tools are there in Av if you use them properly.

The point of this post was that Manual and Av are both a means to an end - you can achieve the same in both modes just in a different way, so one is not inherently better than the other. In Manual you separately dial in shutter and aperture. So you may set the aperture and then set the shutter so the needle appears where you want it on the meter. In Av, you set the aperture, you use EC to put the needle where you want it and the camera will pick the shutter that puts it there (i.e. exactly the same as you'd get in Manual).

So in your first example of shots 2 & 3, the meter in the first probably said -1EV and in the second 0EV - so using EC to get -1EV would get you the same shutter as shot 2. Of course, if you completely ignore the in camera meter the point is somewhat moot and Manual wins as Av is always going off the camera's meter and what it thinks is correct - but if you're using the meter then Av and Manual are equivalent in results and just different in terms of getting it.

as an aside, why did the camera not get the right exposure on shot 1 when it had control of both iso and shutter?

I wondered this also! Or rather, I wondered more about shot 3. Shot 2 is slightly (1/3 stop?) less exposed than the first, and the meter would have been saying the same thing in both cases - so I guess that they average to the 12/18% gray for a "correct exposure". If you'd switched to Av and ISO1000 for shot 1, then it would likely result in the 1/50 shutter you were looking for.

Shot 3 baffled me more though - you're zoomed in less so the crop's changed to let in more of the relatively brighter table. So relative to the first two shots, I would have expected it to meter brighter and therefore suggest a shorter shutter speed than shot 1 (if the ISOs had been the same). Regardless, the meter in both M and Av would be saying the same thing for shot 3 and -1EC would still have matched the M settings.

 

[joescrivens]

Yep, spot on - a camera is never (with current technology ) going to know what the correct exposure is - in fact it's definition of correct is an average of 18% gray (or I've read that camera meters go off 12%?). And it's not going to take into account the various factors that you mention automatically - it's just picking a shutter speed based on what it thinks a correct exposure is, and the user needs to tell it, using EC, how far the correct exposure is from what it expects (put another way, how wrong the camera is ).

absolutely, and if you are doing EC then you are practically using manual anyway, as pointed out already using full manual or using AV but selecting your ISO and using EC do change the shutter is the same thing as just putting it in manual and changing the shutter yourself.

 

[Marc]

absolutely, and if you are doing EC then you are practically using manual anyway, as pointed out already using full manual or using AV but selecting your ISO and using EC do change the shutter is the same thing as just putting it in manual and changing the shutter yourself.

But the point of using aperture priority is that, in constantly changing light, you don't have to keep changing shutter speeds. If you dial in some EC, chances are that it will still expose correctly as the light changes.

At the end of the day, you are using the same light meter whether you shoot in manual or aperture priority so you will get the same aperture/shutter speed combination whichever way you do it so neither one is better than the other.

 

[Janice]

The thing is.. do the AV users KNOW why their shot will come out overexposed BEFORE they take it because of the content of the picture? If not then they willl have to take shots and keep adjusting on the second shot... losing time.

I think its all about the knowledge. If you dont know why or how your camera is behaving then you will have to fiddle about after the event taking other shots with different settings.

That way, and what is making it do that in this particular instance, it can be recitified beforehand. Learning manual is a brilliant way of understanding this behaviour.

Once learnt by all means use AV if you like, but it seems pointless whizzing settings about in AV just cos it comes out too bright, if you dont know what made it do so.

I made myself learn manual and the zone system and expected to then go back to AV but have not used anything but manual and spot metering for the past few years.

 

[trencheel303]

Joe, those photographs you posted all look very soft to me, in fact I'd say slightly out of focus rather than soft.

 

[joescrivens]

But the point of using aperture priority is that, in constantly changing light, you don't have to keep changing shutter speeds. If you dial in some EC, chances are that it will still expose correctly as the light changes.

At the end of the day, you are using the same light meter whether you shoot in manual or aperture priority so you will get the same aperture/shutter speed combination whichever way you do it so neither one is better than the other.

i can see that being useful for sure when you put it that way.

Take my first two examples above though, if you used AV mode to take that shot, you look at the histogram, you look at the back of your camera and it seems like you've got the right exposure, but if you don't have a good knowledge of the features of the camera you wouldn't necessarily know that an ISO of 3200 was going to create noisey images and that you could get better results yourself.

I guess what I;m saying is that Av mode doesn't necessarily create the best results for someone who doesn't have a good knowledge of the camera. The same is true of manual, but people are suggesting that manual isn't a good starting point for a newbie - I have to disagree, it gives the steepest learning curve and actually after using it and perfecting it you probably can then use Av mode correctly and get more out of it.

I might even use it myself now with this EC stuff, now that I have a good understanding of manual.

 

[joescrivens]

Joe, those photographs you posted all look very soft to me, in fact I'd say slightly out of focus rather than soft.

thanks for that, thats really useful to our discussion on Av vs manual ...:shrug:

 

[Marc]

The thing is.. do the AV users KNOW why their shot will come out overexposed BEFORE they take it because of the content of the picture? If not then they willl have to take shots and keep adjusting on the second shot... losing time.

I think its all about the knowledge. If you dont know why or how your camera is behaving then you will have to fiddle about after the event taking other shots with different settings.

That way, and what is making it do that in this particular instance, it can be recitified beforehand. Learning manual is a brilliant way of understanding this behaviour.

Once learnt by all means use AV if you like, but it seems pointless whizzing settings about in AV just cos it comes out too bright, if you dont know what made it do so.

I made myself learn manual and the zone system and expected to then go back to AV but have not used anything but manual and spot metering for the past few years.

Yes, I understand that using Manual is a good way of learning but my point is that when you use manual, you are still using the camera's light meter so, when you set up your shot, you set it so that the pointer is in the middle and take your shot. You then check your shot on the screen and adjust the shutter/aperture to suit and retake. In aperture priority you do exactly the same. If lighting is constant, I'll use manual, if it's changing I'll use aperture priority with EC if necessary.

I can see the shutter speed the camera is selecting in the viewfinder so I can still see what is happening with regards to the relationship between shutter speed and aperture.

 

[Marc]

i can see that being useful for sure when you put it that way.

Take my first two examples above though, if you used AV mode to take that shot, you look at the histogram, you look at the back of your camera and it seems like you've got the right exposure, but if you don't have a good knowledge of the features of the camera you wouldn't necessarily know that an ISO of 3200 was going to create noisey images and that you could get better results yourself.

I guess what I;m saying is that Av mode doesn't necessarily create the best results for someone who doesn't have a good knowledge of the camera. The same is true of manual, but people are suggesting that manual isn't a good starting point for a newbie - I have to disagree, it gives the steepest learning curve and actually after using it and perfecting it you probably can then use Av mode correctly and get more out of it.

I might even use it myself now with this EC stuff, now that I have a good understanding of manual.

I think the confusing issue here Joe is that you seemed to be using auto ISO with aperture priority, something I would never do.

 

[joescrivens]

I think the confusing issue here Joe is that you seemed to be using auto ISO with aperture priority, something I would never do.

well, actually I used both auto and fixed as it seemed there were different people using one or the other, neither gave me the right results, but with some EC I could have got what I needed

 

[joescrivens]

Yes, I understand that using Manual is a good way of learning but my point is that when you use manual, you are still using the camera's light meter so, when you set up your shot, you set it so that the pointer is in the middle and take your shot. You then check your shot on the screen and adjust the shutter/aperture to suit and retake. In aperture priority you do exactly the same. If lighting is constant, I'll use manual, if it's changing I'll use aperture priority with EC if necessary.

I can see the shutter speed the camera is selecting in the viewfinder so I can still see what is happening with regards to the relationship between shutter speed and aperture.

what about those of us who don't use the light meter at all when using manual though? I know I often just go with the settings I've used before that I know will work without even looking at the light meter

 

[Janice]

when you set up your shot, you set it so that the pointer is in the middle and take your shot. You then check your shot on the screen and adjust the shutter/aperture to suit and retake. In aperture priority you do exactly the same.

Ah that's where you are wrong.. I hardly EVER have my pointer in the middle. If you have the pointer in the middle for 80% of your shots you shouldnt be using manual.

I spot meter from a zone i know the tone of and set that on the meter as +1, -1, -2 or whatever. That way 95% of my shots come out perfectly exposed first time without the need for a second shot.

Thats just what i was saying about AV needing trial and error and other shots if people dont know what their camera is about to do before they take it.

If you learn that then you minimise loads of time and card space with properly exposed first time shots.

 

[Dogfish_magnet]

But the point of using aperture priority is that, in constantly changing light, you don't have to keep changing shutter speeds. If you dial in some EC, chances are that it will still expose correctly as the light changes.

At the end of the day, you are using the same light meter whether you shoot in manual or aperture priority so you will get the same aperture/shutter speed combination whichever way you do it so neither one is better than the other.

- thats what i sould have said right at the start !

 

[dfawkes]

I think the confusing issue here Joe is that you seemed to be using auto ISO with aperture priority, something I would never do.

At the risk of derailing the thread, why is that fabs? Given it only works in Av, Tv, P and A (in Manual it reverts to 400) then I see it as the one time you would use it?

I normally rock around with Auto-ISO on in Av, but I'm keeping an eye on the shutter and the ISO and if one of them strays somewhere I don't like (1" shutter, 3200 ISO) then I'll stop and adjust. But generally I'm happy with letting auto-ISO float around 100-400 to get me a reaosonable shutter. I wish you could put a custom ISO upper limit and shutter lower limit for Auto-ISO so that I didn't have to stop and e.g. change the ISO back to 400 if it strays above that. But maybe I'm just lazy!

 

[Marc]

what about those of us who don't use the light meter at all when using manual though? I know I often just go with the settings I've used before that I know will work without even looking at the light meter

Ah that's where you are wrong.. I hardly EVER have my pointer in the middle. If you have the pointer in the middle for 80% of your shots you shouldnt be using manual.

I spot meter from a zone i know the tone of and set that on the meter as +1, -1, -2 or whatever. That way 95% of my shots come out perfectly exposed first time without the need for a second shot.

Thats just what i was saying about AV needing trial and error and other shots if people dont know what their camera is about to do before they take it.

If you learn that then you minimise loads of time and card space with properly exposed first time shots.

There's a lot of ifs there though. I'm talking about general use where you are starting from scratch and need to take your initial reading from the camera's light meter. Most people can't look at a scene and say for definite that they need fx.x and 1/xxx shutter speed and to underexpose by x stops. You can guess from experience but there are plenty of variables so you are not always guaranteed to get the perfect exposure.

 

[Marc]

At the risk of derailing the thread, why is that fabs? Given it only works in Av, Tv, P and A (in Manual it reverts to 400) then I see it as the one time you would use it?

I normally rock around with Auto-ISO on in Av, but I'm keeping an eye on the shutter and the ISO and if one of them strays somewhere I don't like (1" shutter, 3200 ISO) then I'll stop and adjust. But generally I'm happy with letting auto-ISO float around 100-400 to get me a reaosonable shutter. I wish you could put a custom ISO upper limit and shutter lower limit for Auto-ISO so that I didn't have to stop and e.g. change the ISO back to 400 if it strays above that. But maybe I'm just lazy!

I usew aperure priority purely to automate the shutter speed in changing light, I would rather control the iso myself.

Oh and my camera won't use auto iso in manual.

 

[dfawkes]

Fair enough!

 

[joescrivens]

well I think the moral of the story is to use whatever gives you the best results, and everyone is different, if Av is getting you the best results then thats what you should choose, if like me Av doesn't give you want you want and manual gets you a better photo then use manual.

 

[HoppyUK]

well I think the moral of the story is to use whatever gives you the best results, and everyone is different, if Av is getting you the best results then thats what you should choose, if like me Av doesn't give you want you want and manual gets you a better photo then use manual.

After 115 posts...

 

[Tom Harper]

Does anyone ever use exposure braketing to make sure they get the shot or do you just rely on RAW processing to make fine adjustments to the exposure if needed?

 

[joescrivens]

After 115 posts...

it's good to explore these things!

 

[Arkady]

...If you have the pointer in the middle for 80% of your shots you shouldnt be using manual.

I spot meter from a zone i know the tone of and set that on the meter as +1, -1, -2 or whatever. That way 95% of my shots come out perfectly exposed first time without the need for a second shot.

...

If you learn that then you minimise loads of time and card space with properly exposed first time shots.

Pretty much as I do...must come with practice and experience, I guess...

 

[Marc]

I spot meter from a zone i know the tone of and set that on the meter as +1, -1, -2 or whatever. That way 95% of my shots come out perfectly exposed first time without the need for a second shot.

Actually that's the one bit I don't understand. What do you mean by a zone you know the tone of and how do you know whether to set +1, -1 or whatever?