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  1. #41
    Join Date
    Feb 2006
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    Angry What appears to be Chromatic Aberration issues

    I am looking at the various images I am producing with BOTH lenses (60/2 & 90/2.8) and I guess I am a little "weirded out" by the chromatic aberration I see from the 60/2. I suppose (notice how sure I am about this) what has me concerned is that TAMRON touted the improvement of this 60/2 by adding two SD elements to reduce chromatic aberration from the lens ... and to me, it seems worse.

    Simply look at the image, below, and at the horizontal lines of the shaded area.

    The 90/2.8 left no color attributes of this type in its shot, and, again, the 90/2.8 image looks "sharper" and of higher contrast.


    Yes, BOTH images were shot at an aperture of f/2.8, the 60/2 in APS-C capture mode and the 90/2.8 in Full Frame (normal) ... the labels just identify which image is from which lens. All things considered, I would have expected a much crisper image from the 60/2 and NO CA chromatic aberration issue with the parallels.
    Last edited by DonSchap; 05-27-2011 at 05:20 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  2. #42
    Join Date
    Nov 2008
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    Monmouthshire, UK
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    Don, I'm not sure that this should be a total surprise. Photozone.de said this about the 60mm Tammie...
    "The amount of lateral CAs (color shadows at harsh contrast transitions) is higher than one would expect from a prime lens. With values around 0.8 pixels at the image borders throughout most of the aperture range they are no show stopper, though. In addition, CAs can easily be removed in post processing"

    Even so, although the 90mm is better, it's not that much better in CAs. Resolution wise there is not a lot of tested difference between the two but as we know there can be differences between lenses and even a very small mis focus can cause CAs as well as the loss in sharpness.

  3. #43
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    Unhappy Making sure...

    Peter ... I took a lot of time to get the focus dead on, with Micro-Adjust. The 90mm took no time at all. These images simply tell you that the 60mm is not the 90mm. Their performance is vastly different, and if you want the better shot, the old lens is the way to go. If you want focus speed and convenience, and arre willing to accept compromise in you IQ, the 60mm is the one. I have both ... I have a choice.

    Still, I am troubled to see that nothing has significantly changed with the 60mm that I received back ... and I am wondering what camera body they are throwing it on to get the adjustment checked?
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  4. #44
    Join Date
    Dec 2006
    Location
    God's Country - Australia
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    10,424
    A few comments. Try the 60mm on the a700 just to rule out any strange software thing going on when you use apsc mode on the a900. the faster the glass the more chance there is for CA in and of itself and alsocfor that CA to detiriorate the sharpness of the images when ahot wide open.

    That image you showed is certianly not consistent with the results i have seen from the 60mm, nor is it consitent with photozones review. It looks OOF to me.
    D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75
    flickr

  5. #45
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    a700 example

    On the α700, the 60mm f/2 MACRO is back-focusing about 10mm (1 cm) off, with a subject distance of about 16-inches. Now, with some distance, that may not be considerable, but with a MACRO, that just stinks. Unlike the infamous battery test, you cannot allow for such slop.

    Original frame, α700 (spot focus on the "28")
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    Same shot, α850, "+/-0" Micro-Adjust, APS-C Capture
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    If you draw two diagonals from corner to corner in the framed images, you will see the center of focus is on the "28", not the "35." That is BACK-FOCUSING of a lens and it makes the difference between the "keepers" and the "crappers."

    I do agree, if you have a lens that is O-O-F, then you will cast CAs. That is precisely WHY it has to be precise when it focuses. If anything, it is the telltale sign that something is askew and needs to be fixed. If you manually focus, your eye makes the choice of whether something is "in focus" or not... and you manually correct for it with the lens' focusing ring, but AF requires the lens be exactly aligned to give proper focus. I have had too many examples in the past of this problem ... and for the most part, I have had it adequately corrected for the lenses. That is, until now. As a customer, I would like this lens to work as it should ... not, as I have to correct it.
    Last edited by DonSchap; 05-29-2011 at 08:10 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  6. #46
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    Dec 2006
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    God's Country - Australia
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    images arent from a tripod so are at different distances and angles. hard to tell much from that. to my eyes, the a700 image looks sharper, better resolved and has far less CA. which confims alot of what ive been told about aps-c crop modes in FF cameras. its not quite up to the standard of a dedicated aps-c sensor. especially considering the a700 is quite dated now.
    D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75
    flickr

  7. #47
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    Nov 2008
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    Monmouthshire, UK
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    As I've said many times... aww, why bother! See post#8.

    I don't know anyone, using a macro at macro distances, who doesn't rely on manual focus.

  8. #48
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    Dec 2006
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    God's Country - Australia
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    peter, i rarely use manual focus for macro, i detest MF with a passion so i try and avoid it at all costs.
    this shot with the 105VR is not too far off MFD using AF and its dead on.


    Untitled by .Chris.K, on Flickr

    and this is with the 60G macro. again, using AF and they are bang on.


    Untitled by .Chris.K, on Flickr


    Untitled by .Chris.K, on Flickr

    i have owned the tamron 90mm and loved it but dreaded the success rate. same with the sigma 150/2.8. they just dont focus accuracy or fast enough for my liking. you just need great glass. it makes all the difference
    D800e l V3 l AW1 l 16-35 l 35 l 50 l 85 l 105 l EM1 l 7.5 l 12-40 l 14 l 17 l 25 l 45 l 60 l 75
    flickr

  9. #49
    Join Date
    Nov 2008
    Location
    Monmouthshire, UK
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    Why do you hate MF?
    Anyway, choosing to use MF with Macro has nothing to do with great glass.
    It's a personal choice and you have every right to go your own way but I'm pretty sure I'm right in what I said.

    Are you sure those images are close to 1:1 BTW?

  10. #50
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    Feb 2006
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    Des Plaines, IL
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    Inability to get it right...

    Focus alignment on a PRIME lens should not be that hard to correct. CAs are incidental ... the focus will solve a lot of it. It is clear to me that the focus is the same on both images -> problematic.

    I guess I will resign myself to spending another $20 in shipping, as back it goes, for alignment. I don't know who they have doing this, NOW, but I AM NOT IMPRESSED.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

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