In this post I will be showing samples from the Canon PowerShot S95 and the Canon EOS 550D (or Canon Digital Rebel T2i). This time the main goal is to see how different ISO settings – from low to high – affects the picture quality – mainly the noise levels but also colour saturation.
As always all of these samples are full size and have not been edited in any way – except changing the filenames! I have taken a series of pictures of the same motif with the two different cameras: Canon PowerShot S95 and Canon EOS 550D (with the kit lens EF-S 18-55 mm IS) – mostly as comparison – but they are interesting on their own as sample pictures from the 550D! I know it is VERY unfair comparison because of sensor size, price … etc but at least there is something that can be used as a sort of “gold” reference. A compact would have to work VERY hard to surpass any decent DSLR as the ISO goes up – and the light goes down! Give me sun (or rather low ISO) and the pictures are very good from all cameras!
NOTE! I forgot to reset the contrast and saturation on the 550D to factory setting – so the pictures can not be directly compared between these two cameras! I will redo this as soon as I have a chance! Sorry for this!
As I like to see how the cameras work under real world situations (and I am also quite lazy 😉 )I let the respective cameras handle most settings automatically – only intervening at special situations or at price winning photo opportunities!
Both cameras were set similarly: Programmed Automatic Setting (P), AWB, all other settings to normal. Note that the sharpening on 550D is normally set for “soft” from Canon – I did not change that!
I will of course put up the full-size samples – but I will also put up what I call “PhotomanCompareStrip” – where I have taken the same (what I think is) representative area of the picture for each of the different ISO values. This way you can very quickly see how higher ISOs affect the picture quality. I have saved the “PhotomanCompareStrip” as PNG-files so the picture quality in the crops will not be affected by one more destructive JPG-compression! Be sure to click them to see the crops in 100% size! Well, you will see below what it is – I hope you will find them convenient ! 🙂 For a more detailed look I do recommend the full size samples!
For the following I think it best to explain what I mean by “pixel-by-pixel” and “full screen”. Firstly “pixel-by-pixel” is when you size the viewing of the picture on the screen so that each pixel in the picture will be show as one pixel on the screen. This means that you can only see a (small) part of the picture but can scroll around to see other parts of the picture. Secondly “full screen” is when you scale (down) the picture so that you can see the full picture on the screen at once.
Canon S95 Samples – ISO 100 and 200
Both ISO 100 and 200 are quite good with the S95 – I think. No disturbing noise and hardly any loss of detail! definitely nothing that can disturb your eyes if you look att the picture full screen on any normal computer!
Canon S95 Samples – ISO 400 and 800
ISO 400 is still quite good – but with some minimal loss of detail that you only can see on a pixel-by-pixel view! At full screen viewing some loss of contrast creeps in. Again you can not see any flaws in sharpness if you look att the picture full screen! The same can not really be said about the noise – which if you look very carefully at evenly lit areas – the sky for example – can be seen or at least “felt” even at full screen – and definitely at pixel-by-pixel viewing! It is not very disturbing – if at all seen in full screen! ISO 400 is not att all bad and I would say that it is good enough for most purposes!
ISO 800 is still good enough – especially for full screen viewing. You can see differences between ISO 100 and ISO 800 but the later it is definitely still good enough to be used in most situations – even if big size printing will show some noise! Looking att ISO 800 on pixel-by-pixel shows that it is here that the image quality starts to be affected more clearly. Noise, sharpness and contrast are all affected.
Canon S95 Samples – ISO 2000 and 3200
ISO 2000 is really an amazing sensitivity – but you pay for it in noise, sharpness and contrast which all are affected. It is still quite alright to view full screen – but now you can quite easily see the noise in the sky and less detail and less contrast in the tree branches at the and of the street. Looking at it pixel-by-pixel you see a significant drop in image quality even compared to ISO 800! Most details have been lost and it has to be said that ISO 2000 should only be used if you really have to to get a picture! Still alright for big objects that fill a bigger part of the picture – but do not at all expect that razor sharpness! Compare it to the Canon EOS 550D picture below for ISO 1600 and you will realize that even if the S95 has a much developed new sensor it is no match for a bigger sensor – but the S95 sensor and processing certainly stands well up against other compact cameras. Compared to my previous “new sensor compact” Samsung WB2000 the S95 has more colour saturation as standard!
ISO 3200 is actually not much worse than ISO 2000 – so much of the same comments apply here! There is some more loss of detail but the big step seems to be between ISO 800 and 2000!
One thing to note: The ISO 3200 sample is slightly over exposed! The camera indicated this – as its aperture does not go any smaller the f 8.0 and the shutter time not any shorter than 1/1600 sec there was too much light for it to handle at such high ISO value.
PhotomanCompareStrip – Canon PowerShot S95
As I have given most comments on the full size samples I will here only observe that you can very easily see the first big drop in resolution when you step up to ISO 800. This is very good – as you normally will not have to go any higher than ISO 400 in outdoors daylight photography. Indoors, restaurant, candle light you might be more willing to accept a little more noise and softer pictures… You can also use the S95 flash – which I seem to love to hate – its annoying but good – if you accept the flat light from a built-in flash. Even if contrast and saturation is affected by the increase in sensitivity there is a very good general similarity between the pictures taken with different ISOs.
Canon EOS 550D Samples – ISO 100 and 200
As this review is of the Canon PowerShot S95 I will not comment the Canon EOS 550D samples.
Canon EOS 550D Samples – ISO 400 and 800
Canon EOS 550D Samples – ISO 1600 and 3200
PhotomanCompareStrip – Canon EOS 550D
A few general comments on the Canon EOS 550D samples. The image quality is amazing with perfectly acceptable results up to ISO 1600 – with very litte loss of detail or colour saturation and very well controlled noise. At ISO 3200 there is an increase in noise and a certain loss of detail but it is still quite enjoyable – especially full screen where you will see almost no loss in image quality. Looking at the picture pixel-by-pixel it looks softer than at lower ISOs and the noise is higher but still well controlled and not very disturbing – especially considering it is a 18 Mpix picture you are looking at!
More in part #2 of Canon S95 samples! 🙂