Why is this blurry?

UmmmHowsThatUmmmHowsThat Registered Users Posts: 93 Big grins
edited June 4, 2014 in Technique
Hey everyone,

I shot at the Greenwich Concours yesterday and a bunch of my images (thankfully not the majority) have this blurry glow to them. You can notice it most around the wheels.

MaseratiBlur_zps0f0dc2f3.jpg

The specs on this shot are:

Nikon D610.
70-200 F2.8
200mm
F3.2
1/1000

It doesn't look like camera shake. I had a polarizer stacked on the UV filter. I can almost rule that out though because not all images look like this.

Any suggestions or input would be great, thanks. I can also provide a few more pictures if needed.

-Bryan
-Bryan

Comments

  • ziggy53ziggy53 Super Moderators Posts: 23,763 moderator
    edited June 2, 2014
    You are getting specular highlights (large glints) on the shiny areas. The direct sunlight and high reflectance of the shiny areas contribute to the phenomenon. Some of the areas are greatly over-exposed, and devoid of any detail, leading to the "fuzziness".

    Under these conditions of direct sunlight and shiny surfaces and from this vantage, there is little you can do about it.

    I suggest changing your vantage in the future. Sometimes, using a polarizing filter can help, although I don't think that it would in this case.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • UmmmHowsThatUmmmHowsThat Registered Users Posts: 93 Big grins
    edited June 2, 2014
    Thanks for your response, ziggy. I did have a polarizer on, but I bet I didn't bother turning it because there weren't reflective surfaces that I thought would benefit from it.

    Do you thinking stopping it down would have helped? Or maybe underexposing it?

    Thanks!
    -Bryan

  • pathfinderpathfinder Super Moderators Posts: 14,694 moderator
    edited June 2, 2014
    Hi Bryan, Welcome to dgrin

    Why did you stack a UV filter beneath your polarizing filter? Was UV light a consideration in this image?

    Why did you choose f3.2 - did you want/need the shallow field it would capture? Your lens is certainly sharper down 2 or 3 stops to a smaller aperture. A 200mm lens at f3.2 at about 10 - 15 feet from the focal plane has a depth of field of between 0.1 to 0.2 feet or about 1 to 2 inches. From DOF master.

    Why a shutter speed of 1/1000th for a stationary car? Could you not have shot this at 1/250th at f6.3 and gotten more depth of field, and still not had that much camera movement at 200mm with an IS/VR lens? Handheld or tripod shot?

    I use multiple filters at times - like a CPL and an 8 or 10 ND, but I know of no reason to use a UV filter these days. With respect, I submit that a UV filter will degrade your image ever so slightly.

    Under exposing will have no effect of specular reflections of sunlight, unless you want to under expose 8 to 10 stops or more...

    Has this image been sharpened in Photoshop? I think High Pass filter sharpening will help it a bit.

    Just some thoughts of mine about the sharpness of your image. As the image is only ~ 1000 pixels wide it is hard to really evaluate sharpness as critically as I might prefer. But yes, the red curve behind the driver's headrest does not seem razor sharp on my monitor, and I see the image "glow" softly too.


    If you were shooting at f3.2 to blur out the background as is frequently done at car shows, I don't think the background is blurry enough to succeed here. My opinion, only, of course. I prefer to do my background blurring for car shots in Photoshop after the fact, where I have more precise control of the outcome. It is more work, but it sometimes is more successful at isolating the beautiful car you want to viewer to see.

    Precisely where was your single AF focal point for this image? There is certainly more than a couple inches between the front and rear wheels in this image relative to your focal plane I suspect as well.

    This discussion really is about shooting technique, not photofinishing, image editing, and hence I will move it to the Technique forum.
    Pathfinder - www.pathfinder.smugmug.com

    Moderator of the Technique Forum and Finishing School on Dgrin
  • ziggy53ziggy53 Super Moderators Posts: 23,763 moderator
    edited June 3, 2014
    Pathfinder, as usual thumb.gif, raises some good points.

    Specular highlights can cause additional lens flare with filters and stacked filters, possibly leading to an exaggerated effect in the image.

    Definitely test to see how much impact that combination of filters might cause, versus no filters.
    ziggy53
    Moderator of the Cameras and Accessories forums
  • UmmmHowsThatUmmmHowsThat Registered Users Posts: 93 Big grins
    edited June 4, 2014
    Hi Pathfinder,

    Thank you for the welcome. I've been here for a while, but don't really post much. I appreciate the in-depth reply.

    The UV filter is always on my lens for protection.

    I shot at F3.2 for that shallow DOF. I prefer to capture it naturally if possible, rather than create it afterwards in either PS or some other program. I kept the point of focus at the center dot for some reason. I will definitely look into the focal plane measurements, too, so I can be accurate in choosing the correct F-stop to capture the entire car in focus.

    I shot at 1/1000 of a second because it was F3.2. Although it still is a bit overexposed.

    I have not sharpened it in PS, but I will give that a go and see how it works out.

    Thank you for your input. I will look more into the focal plane and things along that line.

    -Bryan
    -Bryan

  • perronefordperroneford Registered Users Posts: 550 Major grins
    edited June 4, 2014
    Based on the detail of the car behind this red one, and the sharpness of the grass BEHIND this car, I'd say you missed the focal point. At least on this shot.
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