I have corrected the perspective distortion in the original, but I'm afraid the lady is still leaning back. Perhaps she also sets her tripod up in the same manner.

It is generally accepted that the 1/3rd to 2/3rds stands as a rule of thumb for most situations. However, the lenses computed for my 5" x 4" camera are said to be equal distances fore and aft from the focussed point. But then, my Sinar has so many options for selective focus. In the good old days, focus ranges were marked on the barrel of lenses, where one could quickly set the hyperfocal distance. Best example of this, was the Hasseblad lenses where the two extremes of focus range were shown by a pair of moving red markers.These moved wider and closer, as the aperture was selected.

I have had CHR error in the past. I seem to remember switching off remove the card, replace card, and if empty, re format. If card already has images on, perhaps try another card, and download problem card from card reader to computer. Then reformat the suspect card. The problem will disappear by trial and error efforts, but can be worrying when it first happens.Even just removing and replacing the card can yeild success result.

With that professional looking tag T.A.Photography, I'm surprised a professional would need to ask. You must have got your experience from somewhere.

I also had one of those, but in it's day,1960's, it was a useful lens. Suffered a little from distortion at either end of the zoom.

Following on from previous thread about the difference between my two mirror lenses, here just sample shots from both. The focus distance was 50ft, so had to use a 10mm extension ring with the Sigma. The cap refered to is donut shaped (Hole in centre). Shot in Raw + Jpeg, these are the Jpeg shots.
Hope the upload works

From f4 to f8...is TWO stops different. They are very similar as regards clarity. Have posted another reply also.

The Sigma is f4...The Nikon is f8. That is TWO stops different.. f4..f5.6..f8.. On the Sigma lens there is a front lens cover that has a removable centre circle, on a swivel stud fastenening. After focussing, the cap with centre opened can be re-placed and gives a comparative f5.6 aperture. Lenses compare with each other regards clarity, but the Nikon is easier to handle. Could not possibly hand-hold the Sigma. And as they both have tripod mounts, that is how I use them.The obvious benefit of the Sigma is the f4. aperture.

Wonderful posting. I wonder though, did you ever shoot a wedding on medium format roll film? I read that todays vogue is to shoot masses too many for the couples to comprehend and choose for their album.

My 500mm Reflex Nikkor C f.8 lens has focus markings from 13 ft. to 150ft. but focus movement goes a fair way beyond the infinity mark. My Sigma 500mm Mirror lens f.4 has focus markings from 50ft to 300 ft. Really only useful for distant subjects due to the very narrow DOF.

I have the younger brother of your Ball-head (just one locking lever). The extra knurlled base ring was made by an engineering friend. The top plate can be reversed to give the different thread size to accomodate camera.

Thanks .............Will try that next time I open Picasa.

I use Picasa as a 'Create a Gift CD' programme. But find it very annoying to have this other function running at the same time , loading all of my older images into the Picasa file/folders. Sometimes interupting what I am trying to do on the Gift CD work.I have searched the whole screen to find a way of stopping this other function running but no luck yet. Some time ago before I installed this Picasa programme I seem to remember the same problem was happening to others. One person stated that there was a tick box to stop this, but I haven't found it.

At a Nikon seminar, the technician recommended to leave settings as 'Normal' in camera, and do adjustments in post process.