This clip is of Bob Grimstead practicing his display for the 2008 Red Bull Air Race on the Swan River in Perth Western Australia.

Be warned, it is quite a long clip of the entire sequence so is a big download

I put a 1084mm f10.5 MTO mirror telephoto on a Letus Extreme 35mm adaptor attached to a Sony PMW-EX1 camera. Way overkill and well inside the f5.6 boundary for artifacts. You will observe at the end of the clip that I finally managed to break the Sony grip on CMOS rolling shutter artifacts.

A typical CMOS rolling shutter artifact occurs but only becomes apparent when almost the entire frame is covered by the propellor disk.

Sony definitely seem to have some trick going. When there is a smaller area of rapid movement within the frame there do not seem to be any artifacts.

The camera seems to be also happier when shutter is selected off. You may also observe some horizontal frame shears on rapid movements during the follows. Sometimes these appear to be generated by the encoder during export to the windows media file.



With the 1084mm lens, the image becomes a five degrees field-of-view. It is real handful when managing a dynamic subject, something close in equivalance to 600mm with a 2/3" video camera. Another harmonised sighting camera is needed to aquire the aircraft and re-aquire if it is lost from the frame.

The resolution is a bit soft wit this lens.

I have always thought this was typical of the MTO which is quite old. However, I recently discovered that the Nikon mount I have on it appears to have had material skimmed off the face for some reason and backfocus for a Peleng Fisheye was off by 0.2mm when using it.

So I will shim it forward on the MTO and see if this improves things another day.

I substituted this mount on the Peleng because I did not have the correct size grubscrews for the Peleng's own Nikon mount which was otherwise identical in appearance.

For the flying enthusiasts, if you look carefully at the aircraft, you can observe the movements of the control surfaces and even stick movements by the pilot in one of the hammerheads.

The vision suggests that the aircraft is closer to the ground than it really is.

Since the last clip was posted, the propellor on the aircraft has been replaced with a quieter version with slightly coarser pitch. The performance of the aircraft has not been adversely affected but the noise is way down.

FOOTNOTE:


Still images of the rig used for the ground-to-air imaging can be found here :-

http://exposureroom.com/members/DARANGULAFILM.aspx/assets/0f993f3acfe84243a3f9cd2678f8ecfe/
http://exposureroom.com/members/DARANGULAFILM.aspx/assets/7d60e770eb224d6c8705a55bd42cece6/