Viewing 40 posts - 1 through 40 (of 81 total)
  • Lens and sharpness question (camera content)
  • molgrips
    Free Member

    I know I could post this on a photography forum but I really CBA with new forums.. 🙂

    So I noticed yesterday that I am getting far sharper images shooting in strong continental mid-day sunlight than I do indoors or in low light, even when taking ISO noise into account.

    So do things really work better in stronger light even when the exposure works out the same? Or is it the case that even above the traditional rule of thumb camera shake threshold of 1/60 or whatever, shorter exposures still result in sharper pics?

    Or perhaps the high contrast means that the JPGs can be processed better (only eyeballed the JPGs so far).

    flyingmonkeycorps
    Full Member

    Are you shooting at different apertures? Most lenses tend to be a bit sharper in the middle of the f range, I find – my f1.8 Nikon is sharper at f8 than it is at f1.8…

    marsdenman
    Free Member

    Lenses generally perform at their best around f8-f11 – that’s presuming you’re using an SLR.
    If you’re also using the SLR on ‘auto’ the the camera will likely be working at those sorts of apertures as you say you’re shooing in bright sunlight.
    Also – bright sunlight = high contrast which also ‘lens’ an air of sharpness to a picture.
    Indoors / low light typically means less contrast = shots can look ‘softer’ but that is not to say they are not as sharp as photo’s taken in bright sun…

    molgrips
    Free Member

    Not a lot of difference between wide open and middle by all accounts on this particular lens. The difference though is dramatic.

    GrahamS
    Full Member

    Have you looked at your lens on DxOMark – that should give you an idea of where it is sharpest.

    Also high contrast can often make images look sharp, as can having “true” black.

    molgrips
    Free Member

    DxO just told me all my kit is rubbish…

    stumpy01
    Full Member

    What sort of shutter speeds are we talking about indoors??

    I would have thought that for the same settings apart from shutter speed, the image would be just as sharp indoors as it is outdoors – assuming you’re not wobbling the camera about.

    Have you tried sticking it on a tripod indoors, if you really want to investigate it?

    5thElefant
    Free Member

    Contrast and sharpness look pretty much the same. I suspect you’re just seeing contrast.

    marsdenman
    Free Member

    Not a lot of difference between wide open and middle by all accounts on this particular lens

    If it’s a top spec lens that could well be the case and even some ‘kit’ (as in, supplied with the camera, as a kit) lenses can be quite good but they are the exception.
    As a couple of us have mentioned above – it sounds like it’s the quality of light that giving you that look of ‘extra’ (for want of a better word) sharpness…

    GrahamS
    Full Member

    DxO just told me all my kit is rubbish…

    That’ll be the problem then 🙂

    molgrips
    Free Member

    1/30 indoors, IS body.

    I’d be trying this with a tripod, but I am in two minds about buying one 🙂

    As a couple of us have mentioned above – it sounds like it’s the quality of light that giving you that look of ‘extra’ (for want of a better word) sharpness…

    Nods.. that’s kind of what I had been thinking actually. Some other sort of effect rather than actual optics. Just zoomed in on a sunny image (admittedly a high contrast subject) and was blown away by the sharpness.

    Also, come to think of it – I have previously checked out the reviews of my camera on DP review and cannot approach the quality of their studio test image when mucking about with mine. However they are using a tripod and presumably a well lit studio…

    5thElefant
    Free Member

    DXO scales are logarithmic. So I wouldn’t worry too much about your kit not being the best.

    molgrips
    Free Member

    So I wouldn’t worry too much about your kit not being the best.

    Nah, that was tongue in cheek really 😉 My strategy is to buy the cheapest stuff that is good enough then get out and use it. I’d rather have four or five different low end lenses than one really expensive standard zoom.

    b17
    Free Member

    +1 most of what you’re seeing is contrast

    BigJohn
    Full Member

    A shorter exposure reduces blur, a smaller aperture increases depth of field so more of the picture is in focus.

    And sunshine makes us happy.

    bigyinn
    Free Member

    At a guess the camera is able to use smaller apertures in daylight, thus the depth of field is being increased as a result.
    Lower light will mean the camera will select larger apertures, thus reducing the depth of field.

    glenh
    Free Member

    Smaller aperture = sharper image, unless you have some sort of amazing lens.

    This is because it’s difficult/impossible to avoid spatial and chromatic abberations towards the edge of a lens (they are still present in the centre of the lens but to a smaller extent).

    The same effect can be seen with your own eyesight – brighter light = smaller pupil = better focus, because your cornea and lens are only spherical near the centre (this effect is most noticeable if you have a small -ive prescription: stuff is much clearer without correction in bright conditions).

    bigyinn
    Free Member

    I cant believe it took 15 replies before the answer was given. I thought you would have known about DOF in photography Mr Grips!

    5thElefant
    Free Member

    Smaller aperture = sharper image, unless you have some sort of amazing lens.

    Not true on 4/3 cameras. Difraction softness sets in early and the lenses are optimised for sharpness wide open.

    dpreview has a nice interactive MTF graph showing this – Olympus 14-42mm here…

    At 14mm centre sharpness drops as you stop down, although edge sharpness increases. But… by f5.6 it’s all over and it gets softer throughout as you stop down.

    Generally stopping down on 4/3 lenses doesn’t make the image sharper. Quite the opposite. 😯

    I cant believe it took 15 replies before the answer was given. I thought you would have known about DOF in photography Mr Grips!

    Not very relevant with 4/3. DOF is far from razor thin.

    bigyinn
    Free Member

    There was no mention of 4/3 until your post 5thElefant.
    We’re not mind readers!

    5thElefant
    Free Member

    I blame molgrips 😆

    grum
    Free Member

    I blame binners.

    b17
    Free Member

    and DOF isn’t the same as sharpness… (or perceived sharpness)

    perfectly possible to have incredible sharpness with mm DOFs (i.e. macro)

    5thElefant
    Free Member

    and DOF isn’t the same as sharpness… (or perceived sharpness)

    True, but it hides misfocus and hides field curvature. So it can certainly make an image look sharper.

    Talking of misfocus, it could easily be this. You’ll get better focus lock on well lit scenes.

    GrahamS
    Full Member

    For once this thread really is useless without pics… 😀

    vinnyeh
    Full Member

    Molgrips, it’d be a lot more helpful if you could post the images. Without pics, and the exif, it’s shooting in the dark to a degree.

    I generally blame the perception of lack of sharpness on reduced contrast. ymmv.

    glenh
    Free Member

    5thElefant – Member
    Smaller aperture = sharper image, unless you have some sort of amazing lens.

    Not true on 4/3 cameras. Difraction softness sets in early and the lenses are optimised for sharpness wide open.

    Do you know why they do this? Is it because 4/3 sensors aren’t as fast as aps-c/ff?
    Seems like a bit of a compromise to me, since manufacturing/optics practicalities means a lens that is optimised for a wider aperture will surely never be as sharp as lens that’s optimised for the centre?

    molgrips
    Free Member

    I cant believe it took 15 replies before the answer was given. I thought you would have known about DOF in photography Mr Grips!

    DoF not an issue here. Zooming in at the focus point. However it’s possible that the lens does not focus as accurately in low light…?

    EDIT just noticed 5e’s last sentence.

    molgrips
    Free Member

    Sorry..! I will post pics later 🙂

    Do you know why they do this? Is it because 4/3 sensors aren’t as fast as aps-c/ff?

    4/3 are as fast, it’s just the noise that increases.

    There are technical reasons for this afaik, 4/3 is more than just a smaller sensor. Well, it has wider implications beyond the most talked about. The lenses have particular characteristics that follow on from the fact that the sensor is smaller and the flange distance is less. That’s what they mean when they talk about ‘designed specifically for digital’. However I can’t bring the details to mind to repost here :

    glenh
    Free Member

    4/3 are as fast, it’s just the noise that increases.

    Surely that means the pixels are not as inherently ‘fast’. They require more gain to get the same response, hence the extra noise.

    molgrips
    Free Member

    No.. they are the same as on other cameras, but they are smaller and closer together which means they interfere with each other more.

    At least, that’s what I’d read.

    zokes
    Free Member

    Smaller pixels = fewer photons captured = less signal = more noise.

    If the same pixel density in my 5DII was in your 4/3, it would be about 3 MP!

    molgrips
    Free Member

    Don’t diss the 4/3! 😉

    5thElefant
    Free Member

    Do you know why they do this? Is it because 4/3 sensors aren’t as fast as aps-c/ff?
    Seems like a bit of a compromise to me, since manufacturing/optics practicalities means a lens that is optimised for a wider aperture will surely never be as sharp as lens that’s optimised for the centre?

    It’s because of diffusion. They’ve packed so many receptors into such a tiny space you hit physical limits if you stop down beyond (something like) f5.6.

    zokes
    Free Member

    Don’t diss the 4/3!

    I’m not:

    Bigger pixels = bigger sensor = bigger camera = never have a camera with you when you want one

    Hence why I quite fancy an EP 1/2/whatever it is now. The main reason I’ve not got one yet is my fear that I’ll never take the 5D anywhere again once I’ve got one.

    molgrips
    Free Member

    Yar.. you probably read me waffling on here about a pancake for my camera vs an e-pl1. Simpler to have one camera I think…

    5thElefant
    Free Member

    Bodies cost the same as lenses. Having more than one body to do different jobs makes just as much sense as having more than one lens. 🙂

    molgrips
    Free Member

    Except not in this case, when size is the issue. Having a body to be very small is pointless if you are going to fit large lenses 🙂

    I could flog all my 4/3 kit and get PEN kit instead.. hmm..

    b17
    Free Member

    if you’re going to flog it all, get Nikon or Canon instead, then (deep down) you’ll know you’re not compromising on image quality in the name of size…

    molgrips
    Free Member

    Small size is one of my main criteria though. And low cost 🙂

    If I were to buy again I’d very seriously consider PEN or Pentax. Bear in mind my camera was £329.

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