PI Photography

Exercises in Extreme Focal Lengths
Minolta X-20 and Bushnell 10x32 Monoscope



    Okay, this is the first experiment I tried where I was paying some attention to each shot.

    These were taken with my carry camera - the Minolta X-20. It is a 2 megapixel camera with a 3x zoom ( in 35mm equiv - 37mm to 111mm ).

    Each of the photos shown are only reduced in size for display, unless noted on the individual image description. These would normally be larger than most any monitor you are likely to find. The full frame is 1600 x1200 pixels - and these are reduced in size to 400 x 300 ( 25% - or 1/16th the image area of the full image )

mb1.jpg

1
    This first shot is taken at the full wide angle setting - 1x = 37mm equiv here.
    You can also see my finger at the very top of the frame. This camera has the lens at the very upper left corner of the body - so you have to be very careful holding it. The camera is small and that does make holding it a bit more difficult for some.


mb2.jpg

2
    This photo was taken at the full zoom setting for this model - 3x = 111mm equiv here.
    Not quite clear at this distance, I am not using any support of any kind here. Camera only.
    Holding it steady is a bit of a task. You could use a small table top tripod as a handle.

mb3.jpg

3
    This is taken with the Bushnell 10x30 in place. Focal length equiv of 1110mm ! ( 10 x 111mm, or 30x ).
    You must first focus the monoscope, then move the camera into position as best you can - notice the darkening of the corners in the image - I did not have it as centered as I would like. I will try using this combination again. I am in the middle of making a 'mount' for this setup to work together ( bottlecap and plastic for now ).

    Remember, this exact image in its' original size - is larger than your screen.

mb4.jpg

4
    This is a full size piece cropped out of the original image just above. And notice the purple 'fringing' ( Chromatic Aberration or 'CA' ) - this is fairly typical of high zoom ratios and digital cameras.
    But you can still read the letters, and could recognize a face for sure.
    There are techniques to correct for this problem in your photo editing program - but so as to not spend time answering questions - in general - don't. It is a by-product of over exposure, zoom range, and lens quality ( and probably CCD quality also ).



Copyright  ©  2005  ·  Barry A. Kintner  ·  Arizona Investigators Association  ·  A2Z Computer Works - Phoenix, Arizona