Topic: What is this caused by? (Read 2989 times)

EricWHiss · « **on:** June 10, 2008, 04:37:39 pm »

Hi,
I've seen some odd looking flare in some of my image from today and thought I'd post a sample. This was shot with the camera pointed up into the leaves from under the Linden tree. It appears I am seeing an image of the leaf shutter in the circular bokeh/flare. Look top left for a light circle with 5 triangular blades. Is this caused by a reflection of a column of light bouncing off the sensor and illuminating the shutter blades? Does this mean the timing is off on the lens shutter? Or something else or just normal

Camera was rollei 6008 with p20 back and lens was 180mm f/2.8 either wide open or close to it. I had the lens hood fitted.

Thanks,
Eric

Graham Mitchell · « **Reply #1 on:** June 10, 2008, 04:44:41 pm »

Think about it - if the leaf shutter were closed, the light wouldn't be getting to the sensor

Those flares spots look like they came from leaves on the tree.

EricWHiss · « **Reply #2 on:** June 10, 2008, 04:49:41 pm »

Added another image where I think its more obviously the shutter and not the leaves - this time its on the right side between the two leaves. It appears from this the shutter is either in the process of opening or closing.

Dustbak · « **Reply #3 on:** June 10, 2008, 04:58:38 pm »

There were issues with the truewide that it would show the shutter blades at certain shutter speeds. These were typically in the 1/30th range faster and slower was no problem.

Maybe this is a similar issue?

EricWHiss · « **Reply #4 on:** June 10, 2008, 05:15:33 pm »

Quote

You must have used a fast shutter speed (1/500sec.). The time it takes to open and close these very large blades is relatively long compared to the total time of exposure. If this weren't such a big aperture lens it would be no problem. In the future you will probably see it happen now and then with the 180mm f2.8, depending on the brightness of the blurry spots and the shutter speed used. Yes, it's normal.
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Hi EPd,

Thanks for your reply and yes you are right I was using a fast shutter - can't say exactly as its not recorded in the EXIF but it may have been 1/500. Your explanation makes perfect sense - is that also why there is no PQS version of the 110mm f/2 and 180mm f/2.8?

Regards,
Eric

Graham Mitchell · « **Reply #5 on:** June 10, 2008, 05:29:52 pm »

Ok, the second image make it clearer. Yes, must be partial shadow cast by blades.

Author Topic: What is this caused by? (Read 2989 times)