Bad bokeh or what?....

[griffljg]

On Sunday, I attended the second Open Day at the Wagners Wellcamp Airport (aka Brisbane West Airport), just west of Toowoomba. As I expected to take photos of aircraft and model aircraft on the wing, I took my Olympus OM-D E-M1 together with the Zuiko 70-300mm 1:4-5.6 lens working through a MMF-3 adaptor (for its effective 140-600mm reach) and the Zuiko 12-40mm 1:2.8 PRO lens.

As expected, the 12-40 worked flawlessly, but I did notice a rather unpleasant bokeh on the 70-300, which I had not noticed previously, when using it on an Olympus E-3:



I am wondering whether it is the bokeh, or whether my image stability settings of S-IS AUTO may have had anything to do with it.

Has anybody else noticed this? - It wasn't a heat haze.

[ameerat42]

Looks like heat haze to me.
Wasn't it a rather tepid day there? Plenty of hot air rising from the tarmac?

[griffljg]

That's what I expected, except that I didn't notice that much of a heat haze. Let me see if I can find another photo which illustrates it better.....

- - - Updated - - -

Here's one:



Notice that the distortion is fairly constant from top to bottom and from left to right in the out of focus section, which is not typical of a heat haze.

[I @ M]

griff, you have great shots of the models.

The background does really look like heat haze combined with depth of field out of focus. I am wondering if you didn't see the haze in your efforts to capture the subject?

I really think that it is a combination of haze and jpeg artefacts when the image is compressed as your camera and lens combination are proven achievers from many images out there in the ether.

Either way, I reckon the models will stand out with the background ignored by most plane owners who aren't into photography.

[griffljg]

Thanks Andrew, but I am not totally convinced. I remember being amazed at how little heat haze there was. But I suppose it could have been as you suggest:- Very shallow depth of field together with a bit of heat haze.

Next time I go and attempt to photograph aircraft, I think that I'll take my Canon EOS 6D gear along as well and do a bit of a comparison.

- - - Updated - - -

It wasn't all bad, from my point of view. Here are some of a model performing aerobatics:

[jjphoto]

looks like heat haze to me.

[ricktas]

As well has heat haze. Remember these model aircraft burn a fairly intense fuel and pump heat, fumes etc out of their mufflers at an amazing rate. I used to be right into model aircraft flying. I reckon it is a combination of general heat, combined with fumes. I think it actually adds to your photos here and works well. If you are still concerned about the lens, go give it a try on a milder day, with a different subject matter, with similar distance from subject to out of focus background and check the resultant photos. I reckon the lens is just fine.

[arthurking83]

I reckon it's a combination of a lot of things.

Heat haze, jpg compression, sharpening, lens rendering(of OOF areas) .. etc.

I don't know if the cameras image stabilization has anything to do with it(most likely not tho).
It's commonly assumed with many stabilized lenses that they can affect bokeh rendering with IS turned on.
But the lens type, design and manufacturer vary so much in this current theory that there is actually no consensus on the topic.

On the images posted tho, I (personally) wouldn't be concerned with the effect. As already said it just looks like heat haze more than anything else, which adds a bit of a back story to the images.

[griffljg]

Thanks Arthur,

One thing that I can immediately discount is jpg compression. - I always take my photos in raw as I KNOW that I will want to post process them. - I can't stand slanting horizons and shadows with absolutely no detail (unless it is intentional)! More recently, I have been using Capture One Pro 8 more than LightRoom. This set were processed in Capture One Pro. While viewing the raw image in Capture One, the bokeh looked the same as the images I have posted on this site.

Olympus stabilises their camera bodies and not the lenses. That is why I was wondering why the bokeh looked different to how I remember it being under similar conditions when using my Olympus E-3.

But I agree with you. - It is probably caused by a number of contributing factors. And it is now starting to grow on me.

[ameerat42]

[whisper]It IS turbulence caused by heat haze.[/whisper]

You say you don't remember it, but that's how the camera records it. The only contributing factors are:
-you didn't notice it
-you take some convincing that it is
-it was enhanced by the compressed view of the 300mm lens (as compared to the wide view by eye)
-what you describe as its pattern above is exactly how it appears
-it is not apparent in the last two pics because of different conditions.

(Nice shots of the planes, BTW.)
Am.
...
(Some time later...)
I found these illustrations:
http://www.google.com.au/imgres?imgu...rt=127&ndsp=46
and
http://www.google.com.au/imgres?imgu...art=77&ndsp=50