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1

Lenses / Focusing Problem with 600mm f/4.0L IS II with 1.4X Extender

« on: February 11, 2013, 09:31:57 PM »

To all,

I've been having a difficult time getting sharp images with the Canon EF 600mm f/4.0L IS II USM and the Canon 1.4x EF Extender II.  Basically, I shoot from my Toyota Tacoma with the lens/camera combination resting on a BLUBB (bean bag).  I turn the vehicle off while taking images.  I've tried where the focusing ring is on the bean bag and not on the bean bag.  Will the movement of the focus ring during AF impact the overall image quality?  That is, is the focus ring turned off during AF?  I've tried placing my hand over the tripod foot, over the hood and under the hood for added stability.  While looking through the view finder I find the had over the hood appears to work best.  I see very little if any movement during this phase.  I took around 600 images of the eagle, and saved only 17 marginally sharp images.  This is a terrible hit to miss ratio.  I have attached several images to show the common out of focus images.  What's really interesting is the strange catch light pattern in the eagle.

I've tried every AF combination and AF pattern available on the Canon 1Dx to no avail.

It is possible that the problem lies with me (i.e. poor technique); however, I've read several articles relating to  proper super-telephoto techniques and try following them as best I can.  If anybody lives near Pendleton, Oregon and is an expert at proper super-telephoto techniques, I would enjoy your company for an afternoon along the Foothills of the Blue Mountains.

Thanks,

Wade

2

Landscape / Geminids over Pendleton, Oregon

« on: December 16, 2012, 07:05:32 PM »

To all,

Mother Nature finally cooperated with the timing of an astronomical event.  It was mostly clear for the first half of the two nights of the Geminid meteor shower. I rented a Carl Zeiss Distagon T* 15mm f/2.8 which, by the way, turns out to be one of the most awesome wide-angle lenses I've ever worked with.  You would not believe how well this lens is corrected, even in the corners.  I stopped it down slightly to f/3.5.  You can see some minor aberrations in the extreme corners; otherwise, it is very well corrected. The Carl Zeiss lens really puts the Canon 14mm f/2.8L lens to shame.

I extracted 31 meteors from thirty 25 second exposures.  Although the meteors occurred throughout the evening of December 13, the true radiant was derived from the underlying background image. It was definitely an excellent meteor shower. It was pretty chilly at 24 degrees with a 15-20 mph wind. There is fog and low clouds in the valley below obscuring most of the cities.

Thanks for looking,

Wade