Why the crappy IQ?

Discussion in 'Photography' started by A_Lee, Apr 12, 2010.

  1. A_Lee

    A_Lee Guest

    Recently, I've been noticing that my pictures are very clear, or crisp at a larger size. I know this is normal, as the larger a picture becomes, the more pixelated it appears to be, unless you take a couple steps back :)

    Below, I have attached a picture I took the other day, at medium size:


    [​IMG]

    Everything looks pretty good IMO, when the picture is sized like above.
    I also attached the exact same picture enlarged at the bottom of this post.

    Canon 40D, 5sec., f/22, ISO100, +1EV; I used the Sigma 10-20 @ 10.
    A used a tripod, a cable release, and [under custom functions] used mirror lock up, and turned on long exposure noise reduction.

    Notice that the cliff house in the left portion of the image is blurry. I did reduce the clarity of the water a little, using Adobe LightRoom 2. However looking at the rocks, and everything else, I am bothered by the lack of IQ ... the blurriness ... or am I being unreasonable?

    [​IMG]

    On a side note, does anyone have any thoughts on the 5DMkI (not the MkII), with regards to noise control, and IQ?
     
  2. Ibn

    Ibn Supporting Member

    What are you using to support the setup when shooting the long exposure? I'm seeing an overall lack of sharpness to the picture. I'm also noticing some CA on parts of the image as well, most noticeable in the lower right. Might want to clean your sensor sometime soon as well.

    5DMKI IQ and noise control is quite nice. Not the same as the MKII, but otherwise, very usable. The larger sensor helps. Make sure you take that into account if you decide to upgrade. You'll have to stop down 1 stop to get the same sharpness as now since the depth of field is shallower.
     
  3. A_Lee

    A_Lee Guest

    Yes, "over all" lack of sharpness -I don't know why I could not get those words out, but you hit the nail right on the head.
    I am using a Manfrotto tripod, with a Manfrotto ball head -I don't remember the models of everything off the top of my head, but I believe the legs are 190XDB; when I took the shot I didn't have any of the legs, or the center column extended at all.

    Funny you mention a sensor cleaning -I was thinking the EXACT same thing this morning. My camera is overdue for one. Do you think the lack of a cleaning might be the issue at large?
     
  4. zepplock

    zepplock Guest

    Try to do f/8, I think Sigma 10-20mm is sharpest there.
     
  5. Ibn

    Ibn Supporting Member

    The sensor cleaning won't help with the issue, since it's throughout the entire shot. If anything, it's an aesthetic mar on the shot, which can be cleaned in PS afterwards.

    The sensor might not be able to resolve what the lens is putting out there as well. I'm seeing that on my dated D2X as well (in comparison to D3 and D3X images).
     
  6. A_Lee

    A_Lee Guest

    Some folks on POTN are suggesting diffraction at f22 ... I don't know why I did not think of that :)
    Thanks Vlad, I'll give f8 a try next I have time to get out.

    Eric -I'd love the 5DMkII, but wow, it costs a ton, new or used. Not to say a 5DMkI is very cheap either though :D
     
  7. Ibn

    Ibn Supporting Member

    f/22, yes that will contribute to part of the issue. I usually stick to f/16 or so due to diffraction on the D2X.
     
  8. A_Lee

    A_Lee Guest

    Does diffraction come from the lens, or the camera body?
    Also, it sounded like diffraction is the main culprit according to some guys on POTN. But is there anything else, you think?
    I have to remember not to close down so far next time :)
     
  9. Ibn

    Ibn Supporting Member

    From the body itself, more specifically the sensor.

    There are some cases where the lens can cause that as well, but I don't think that's the case here (i.e. sensor outresolving the lens).
     
  10. A_Lee

    A_Lee Guest

    ahhh ,got it
     

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