I learned on here it's best to keep ISO down
Tackling this one first, I started to composed a long and technical reply, explaining the level of digital processing and sensor signal amplification and distortion to get from what the sensor actually 'sees' to what is displayed on a screen.. but.... Short answer is that the 'notion' to keep ISO setting low, is a significantly a little legacy distortion from the days of film, when different films actually had different sensitivities, and higher ASA film, often, but not always, came with a consequent higher degree of 'grain', and it was advised to us as 'low' an ASA film as you could get away with. Hence translation to digital, 'use as low an ISO as you can'.. which isn't always that helpful.
In the Digtal-Domain, things work very differently and you have a camera, that has a sensor, that has a sensitivity, and unlike film, you cant change it! It is what it is!
When you change the ISO 'setting' you aren't changing the sensor sensitivity, only the amount of signal 'amplification' applied to the sensors out-put, before the in-camera electrickery starts to try and 'paint by numbers' from it.
The higher you set the ISO 'amplification' so the more processing error the electrickery may make, especially when deciding what 'thresholds' to use between values, which may lead to more 'noise'.. but that's not grain,and isn't all that dependent on the ISO setting, but also the contrast of the scene, and the paint-by-numbers processing that the camera does to make a data-file, or that the display device does from that data-file to make an image you look at.
CONSEQUENTLY, we often work back-to-front, in digital.
With film, first off, the range of ASA 'sensitivities' we could buy was often pretty restrictive. Often no more than 100, 200 or 400. I do recall buying film with an ASA as low as 25, or as high as 3200, but these were peculiarly rare. Now though, typical Digital SLR offers perhaps 100 ISO up to 3200 ISO maybe even more, on demand, at the touch of a button, and changeable frame by frame. Bit harder to swap films for each picture!!!
Anyway, with film, you picked a film with an ASA sort of appropriate to what you expected to shoot, then adjusted frame by frame exposure entirely on the aperture and shutter settings.
So, if you were taking landscapes, in fairly reasonable day-light, you chose 100ASA; If you were taking action shots of the school sports day, you probably picked 400ASA so you could use a faster shutter speed to avoid blur, etc etc.
You would pick your aperture and shutter-speed 'settings' to balance your exposure against that 'fixed' film speed.
NOW, in Digi-Domain, you have 'on demand' ISO seettings, over a much wider range than we ever had film ASA and you can change it shot by shot, if you wish.
So, rather than working as with film, and picking an ASA at the start and then trying to find aperture & Shutter-Speed settings to balance that to the exposure meter, and probably having to compromise something 'some-where', be that shutter speed to use a smaller aperture, or aperture to use a higher shutter-speed, or the over-all exposure to use anything 'close' to ideal....
In Dig-Domain, you can far more easily pick a shutter-speed far closer to 'ideal' to control motion blur for your subject; you can pick an aperture far close to 'ideal' to obtain the Depth-of-Field you want, and then balance the exposure setting entirely on the ISO setting to get the exposure, either to meter reading, or your own preference.
See how the 'keep the ISO down' advice is a little luddite?
You have, on a modern digital camera, usually an enormous range of possible ISO settings; My D3200, goes from ISO100, to ISO6400, plus a 'boosted' ISO 3200 equivalent! That's, a 7 stop 'range' of settings.
The lens, by comparison, has aperture settings from f3.5 up to f22... that is actually only 6 'stop' range of variability!
Possible shutter-speeds, is a bit wider. The D3200 offers up-to 1/4000th, and down-to I think 30s internally timed, but I can go pretty much as low as I want using 'bulb' and counting elephants, or borrowing the daughter's intervalometer to save my counting!
BUT, point is, shutter-sped effects motion blur; Aperture effects Depth-of-Field... these are important to the final image.. what does ISO influence?
Noise.... maybe..... remember, that is predominantly influenced by the image lighting and contrast to start with, and is only more 'likely' to become intrusive at higher ISO 'amplification' settings, AND if the original scene is lacking contrast to start with, and MORE... if you go looking for it via pixel peeping!
So, in the digital world, it makes far more sens to exploit the potential of on demand variable ISO, and pick the exact shutter-speed and aperture you think you need for your shot, then balence the exposure metering with the ISO setting,last, rather than tryng to work as with film, picking that first, then compromising the aperture and shutter to make that selected ISO settig 'work'.
Yup... it probably IS 'better' to use the lowest ISO you may, but, you now have three things you can vary, three settings to decide upon, frame by frame, and aperture and shutter still have much more practical influence on the final image, so if you don't have to compromise them, why do so, and IF you have to make a compromise why compromise those more than ISO?
In full auto the camera seems to close the aperture but up ISO into the 1000,s
See above... the camera's electrickery and 'smart-software' is't vexed by legacy 'lore'.
It is likely picking higher ISO settings than you would, because it is more concerned with the Depth of Focus, and hence the aperture setting, and potental Motion-Blur, hence the shutter speed, than it is than keeping the ISO setting down, probably mostly for its own sake, and questionable ideas about 'noise levels'.
hi all
I have been playing with my camera in manual just to learn
IF you are going to go manual..... and I do have an issue there, that every one goes manual exposure settings, because.. well, thats what the 'lore' suggests! And there's a nice easy to identify 'manual' mode on the exposure dial....
In days of old, 'manual' meant manual EVERYTHING! As said, we had to start by picking a suitable ASA film in the shop! Then we had to maually meter our scene, probably with a separate hand held meter, and then manually make aperture and shutter-speed settings, before 'manually' focusing the lens.... even more 'manually' composing our shot... and ask any wedding-snapper... when it comes to 'taking control', far more is outside of the camera, where posing wedding guests has been described as an excersize in herding cats! Or any studio photographer, where the spend more time arranging lights, or back-drops.
When it comes to the 'idea' of going manual to 'take control' its some-what short-sighted to limit that not just to what controls are on the camera, but even more, just those that effect 'exposure'!!!
I have noted although I am checking my light meter and balancing things up my images are slightly dark.
When you say 'light-meter' I assume the hi/lo level indicator either in the view-finder or on the back-screen.
Another legacy anomaly, trying to work in the legacy way of old film, I suspect.
In my old Olympus OM film camera, that has a wonderfully sophisticated metering system for a film camera of it's era, BUT... inbuilt niggle, is that an inbuilt light meter will ONLY take a meter reading of the 'reflected' light 'Through-The-Lens' or TTL.
If the 'scene' its seeing light from, is predominantly dark, say a black-cat in a coal-hole, it wont get that much light TTL, so it will try and 'up' the suggested exposure to make it brighter.
If, on the other hand, the 'scene' its seeing light from is predominantly light, say a white rabbit on a ski-slope; it will get a lot more light TTL, so it will try and 'down' the exposure to make it darker.
Ultimately, the cameras pretty 'dumb' TTL metering will try and assess the whole scene 'on average' and make a black-cat in a coal hole, just as 'grey' as it would try and make a white rabbit on a ski-slope.
The camera, for all its smart electrickery, hasn't got a clue what its looking at! Its making a best guess.
Now, I have a hand-held meter. Lovely little device, it will take either an 'incident' reading from the light falling on a scene.. or it will take a 'reflected' reading from the light reflected off the subject towards the camera.
If I take an 'incident' reading, then will get an 'average' exposure suggestion, but not dependent on how light or dark my subject may be. So my black-cat in a coal-hole, should come out darker, my white rabbit on a ski-slope should come out brighter, BUT, possibly too dark or too bright.
So I may take a couple of reflected readings off my subjects, and I can 'compare' those to an incident reading, and make my OWN average exposure value, and NOT take the meter reading as 'gospel'
Back to that Olympus OM; part of its fancy metering system is that it contains a 'spot-meter'. It cant take incident readings, only TTL reflected ones, but, the 'spot' function means that I can look at a very small portion of the scene, say a nice mid-grey paving stone, and get a 'pseudo' incdent reading. I can also take 'spot' readings of 'just' high-lights or 'just' shadows, and again, do my own sums to decide what basic exposure value to use for my settings... and fancy function of the OM4, it even has a little 'memory',I think can take four or six spot readings and its electrickery will 'average' them for me....
Now, in Digital; the camera contains a sensor. Mine claims a 24Million 'pixel' one. The sensor doesn't actually have 24 million separate receptors, I don't think, BUT... it's a digital camera, remember, its not making anything I can look at that is even close to resembling a 'picture'. It's recording numbers! (something else, probably with a screen, has to 'paint-by-numbers' to turn that data-file nto something I can look at, pictorially)
So,essentially it's not 'strictly' a camera, its a fancy light meter! It records the brightness of 24million 'spots' across my scene!
Ooooh! My sophistcated OM4 could only remember four or six of them! This little gigimo can remember MILLIONS! More, do as many 'sums' on them numbers as it likes, and with more computer power than it took to put a man on the moon, do them almost instantly!
SO.. the various 'metering modes' in a digtal camera are incredibly sophisticated. Where I could only take four or six spot readings, maybe one obviouse high-lght, one obvious shadow, maybe a couple of mid-tones, and the electrics would average them for me.... the electric-pictur-maker, may get incredibly cleaver about the business, and can take millions of 'spot' meter readings, and can then decide what the 'range' of exposure is and try and find a mid-point to get all that in, but more, can evaluate the rest of the scene, to decide how much is in between those high and low points, and come up with an 'average' exposure value, that will possibly let high-lights 'blow' or shadows 'merge' depending on how much of the scene is either, to get most detail in the mid-tones it measures most of.
Still has a couple of inbuilt problems, though. First is that it's looking at the scene 'through the lens', an still has no idea what its looking at; whether thats a white-rabbit on a ski-slope or a black-cat on a coal-hole, or weather they are in bright or dim light to start with... next it's trying to come up with just ONE exposure value... ONE good average that covers all.
A complicated 'evaluative' exposure system, can probably make a damn good job of a 'best guess' an awful lot of the time.... but, it's still flawed, trying to come up with just one exposure value, when it hasn't gt a clue what its looking at.
That 'smart' programming, though does pack a lot of smart, and will do a pretty darn good job of makng a best guess, most of the time....
But 'Go-Manual'... you turn OFF all that smart programmng!
In manual-mode, you are telling the computer-brain that YOU will decide on the best settings... not the computer.
Now, the electrickery 'defaults' and all that smart programming and evaluative maths, stops working. The exposure indicator in the view-finder or on the back-screen, will be displaying the result of a MUCH simplified 'for guidance only' metering 'average'... probably a very simple 'center weighted average' almost completely disregarding the high-light and shadow readings has taken, to give you a 'quick and simple' exposure indication for you to decide how to tweek one way or another based on what you can see, that the camera doesn't have a clue about.
Hence, it's not surprising that you get a discernible 'difference' in exposure from what the camera in an auto-mode 'calculates' is probably a pretty close best guess, to what you get exactly following the 'for guidance only' indication in the view-finder, and NOT making any adjustment from that, as the camera would, or expects you to.
And its another irony of the "Go manual" lore, that at best, following the 'for indication only' meter reading the camera offers you and making settings to balance that metering, you are often NOT taking the control you presume, you are just mimicking, likely badly, what the camera would try and do automatically for you, much more quickly and with a lot less 'faff'.
I have a number of cameras that have no inbuilt meter. I have to assess the light levels by eye or hand held meter, and then translate those assessments to camera settings. Good fun, and very involved, but also rather tedious.
I also have a few cameras that are more or less 'automatic' as far as exposure control. Simplest is my old Sigma M42 SLR. This has is a full 'manual' camera, it has a swing needle metering display in the view-finder, that gives me a 'center-weighted-average' meter reading TTL for the whole scene, but the 'coupling' only goes as far as changing the needle center for 'hi/lo' as I change the shutter-speed or aperture, which I have to set manually. The OM's are a little more automated, those, the camera sets the shutter-speed to balance what set on the aperture.
On the Sigma, I may be a 'slave to the meter' and ai to always expose when the needle middle. But dont have to. On the Olympus, they try and make me a slave-to-the-needle, setting the shutter speed, to cetre the needle... though can over-ride that usng exposur compensation, or switching to full-manual... which can be more involved and more interestng ad more fun...
BUT... I didn't buy an all singing all dancing electric picture maker with more computing power than a NASA moon-shot project... to chuck that all out the window, and use it like that swing-needle-Sigma! May as well use the Sigma ad be a bit more involved in the job, and not have to spend £1000 to do it!
Which is where this notion that you 'need' to go manual, and then limit yourself to merely going manual as far as exposure control, to 'take control' of that incy little bit, and nothing else, can start to bite you in the bum!
Idea that 'The Pro's Shoot Manual' is something I dont agree with. A pro is so 'cos they get paid! Not necessarily because they are any good! and when you get paid.. time s money! Folk dont pay for pro's to 'faff', they pay them to take photo's! I haven't met many genuine 'pros' who exclusively shoot manual, they use as much automatic easement as they can, to save 'faff' and make money! Thats their job! Going 'manual' as a exercise in displaying camera dexterity, seems to me more something of the amateur arena where there's little or no commercial incentive... but still.
Go manual 'To Learn'.... err... yeah.
I used to teach folk to ride motorbikes... curiously, and it still keeps cropping up, the idea of grabbing a little 125 'cos you don't have to have lessons, and 'teaching yourself' still crops up.... sure you can do it.. but going it alone, like that, no one tells you what to do, what works... you have to work it out for yourself, from your mistakes.. which on a motorbike tends to mean crashing... that can some-what damp any saving fro not buying a lesson... as well as hurt!
In photography, grabbing a camera and trying to 'teach yourself' doesn't have (quite!) the same risk as gabbing a motorbike, and teaching yourself, BUT, you still only learn from your mistakes, and while they may not hurt so much, working out what you did wrong can be a lot more involved.
If you want to 'learn' don't try and do it by trial and error, go get lessons! Learn to do it 'right' right at the start.
And IF you want to learn... look at the big picture... which IS the picture. Messing with 'settings' s but a tiny part of that, and so much more s outside the camera than can ever be in it...
So IF you wat to lear anything, look at the whole field of what you could learn, and go tackle the thing most lkely to make most difference...
Exposure Metering is but one tiny bit of the entirety, and whilst knowing what aperture and shutter speed can do for you, is helpful, understanding metering and where and when, you probably DON'T have to argue with the cameras exposure metering is just as important, and ultimately, unless you are a complete masochist or pedant, going manual (exposure!) settings, is NOT something that is in any-way mandatory, and oft not even that beneficial... IF you understand what the auto-modes are trying to do for you, and how to exploit that small 'easement' to let you concentrate on stuff that IS far more likely to help you get better photo's, like composition, like finding photogenic scenes to start with, like taking control outside the camera, etc etc etc.
Ie, there's some reason for what you have found by trial and error, but in terms of your actual objectives you could be heading down a bit f a blind alley.
