Focus Issue

[mattdueck]

Hey,

I am just going over a couple shots from this weekend and noticed that the left side of the photos seem to be blurred while the rightside is sharp just from the camera. Shot at f8 and would like to know whats going on. I shot a DC-3 just minutes before this one and its sharp from one side to the other, could it be my tele lenses because the DC-3 was taken using my wide angle.

Here is a example for all to see.
http://i1109.photobucket.com/albums/h430/mattdueck/DSC_0029edit.jpg

Matt (Dueck Images)

PS the DC-3 Turbo will be on Flickr this afternoon. If any want to see how well its been kept and used as the workhorse to get people and supplies in and out of the Antarctica.

[gonzalu]

Matt,

A couple of things to look for:

--Heat Shimmer. Were you near a car, wall, sidewalk, tarmac, whatever when you took the shot? And I mean whatever is even remotely possible... For example, one habit I have that I HAVE to kill is to use my car as a support for my lens... that is just a NO NO. The car reflects heat, heat kills images...

--APU exhaust of any sort ANYWHERE NEAR the plane or you or in between you and the plane?

--Previous departure or arrival NEAR the plane?

--Did you have Vibration Reduction or Image Stabilization turned on? Try turning it off. VR Smear is what we call it in Nikon land... it happens more on HIGH SHUTTER SPEEDS than on lower shutter speeds

--Were you panning?

--What lens? Could the elements be out of alignment?

--Does it happen regardless of panning or steady?

--Autofocus mode. SINGLE or CONTINUOUS?

--Was there a full moon and were you standing on your head? Were you wearing your Black Sabbath T-Shirt or the one with an Angel painted on it? :tongue:

Take a look at those things ... I also have had issues with high shutter speeds on my D2Xs that I do not experience at lower shutter speeds... they can be considered OOF on only part of the image.

Cary Liao also recently had smearing/focus issues on part of the frame on one of his cameras and I forget now what his findings ultimately were.

[Zee71]

Matt,

This is what I would do just to isolate the problem. I would take some indoor and outdoor shots with a variety of settings. Evaulate the images for sharpness, chromatic aberration, etc. to make sure it's not a lens issue. If the lens appears to be fine, then it's most likely you have encounter heat shimmer, heat haze, whatever (as Manny stated), etc.. I've shot some photo's and noticed some of my images had more or less the same issues as you. The cause was some sort of exhaust vent on a building off in the distance that I couldn't see with the naked eye. Things like this will make your image useless. Heat off your car is another killer that will render your images useless, even with your engine off your car will still emit heat.

If the problem is with the lens, I would recommend sending it in for a realignment, cleaning, etc.

[steve1840]

I see you guys mentioning your vehicles emmiting heat alot lately and it effecting the quality of images. The last time I came down it was cold and windy when I got to Panera so I would sit in my truck and watch for the planes on approach. I would open the door and hop out as the planes would get close and snap off my shots while standing right outside my door. This in turn had me kind of shooting with the lens pointed over the hood at times. Would I have been better off walking away from teh truck and taking my pictures? Im asking this because I was thinking that next time I come (since it will be warmer...hopefully), I was going to bring one of those canvas folding chairs and set it in the bed of my truck and shoot from there. Would that probably be a bad idea?

[gonzalu]

Steve, I think the BEST bet when you're compressing so much air especially at or near 400mm, the cleaner the path between you and the plane, the better. This is why The Mounds is likely to be the BEST location because you're elevated and away from most natural heat sources other than the planes themselves. Turbulence Separation helps dissipate the engine exhaust from the last aircraft, but on not so windy days, there may still be some in the air...

I started to use my binocs for spotting heat and it works quite well. You need at least 15x to really see the effect well but at 10x it shows. If at Panera, just point to the top of the Wendy's and see how much heat shimmer is there... it goes way up from the building, right to the flight path angle of view between you and the plane. Indeed all my shots from that general vicinity usually show problems ... you can really see this heat shimmer. Also if you want to test your car, place the binos front element on the hood or roof of your car and look through it at the distance and see if you see the shimmer...

From the bed of your truck should be not as bad, but I would stand and not shoot across the roof of the cab...

[steve1840]

That makes alot of sense. When I was shoting last time in the Panera parking lot I was against the fence (well snow pile) behind McDonald's and was shooting by starting over McDonald's and panning as the planes went by. I probably got some heat shimmer rising up from McDonald's also in that case. As far as shooting from the truck bed, next time I plan on backing up to where ever I shoot from so that I'm pointed away from the truck and it wont come into play. As far as sitting, I would really only use the chair and sit while waiting for the next flight to approach. The more I think about it, I may not want to even shoot from teh bed of the truck since I wouldn't really have a solid base (trucks suspension and movement) to stand on like I would if I were on the ground.