1.Relative resolution across the field for every(prenominal) second stop from wide open
2.Optimum aperture.
My common format is 35mm film and the lens I use the most is my edict 50mm f/1.8, which is the standard for 35mm film.
Elements: 6
Groups: 5
Minium aperture: f/22,
supreme aperture: f/1.8,
Closest contracting outgo: 0.45m.
A quasi-symmetrical number with a combination of air-spaced and cemented elements either side of the stop.
I go out be testing this lens at two operative distances,
1.Closest focus 0.45m
2.3 m
My Working apertures for two distances,
F/2
F/4
F/8
F/16
I felt up CD/Album covers gave me the move of detail required to test the resolution of such lens at its closest focus distance of 0.45m.
At 3m away there is a range of items with all display this range of detail too.
Procedure at 0.45m
Camera word picture ISO 100
F/2 @ 1/250
F/4 @1/60
F/8@1/15
F/16@1/4
Procedure at 3m
Camera exposure ISO 100
F/2 @ 1/250
F/4 @1/60
F/8@1/15
F/16@1/4
I used ILFORD FP4, which is the black and white film I use the most and processed it in ID-11 as I normally would with a 1:1 dilution at 20 degrees for 11mins.
Reference 13x 18cm prints were made of each aperture for both distances,
Print exposure, distance from paper to film was 38cm
0.45m = f/8 @ 9sec on ramble 3 ½
3m = f/8 @ 6sec on grade 3 ½
Resolution 5x7 cm prints centre vs corner, at maximum magnification possible with my enlarger, using same telephone exchange zone of enlarger lens.
Print exposures, distance from paper to film was 163cm
0.45m
marrow squash = f/8 @ 2.30min on grade 3 ½
progress = f/8 @ 2.20min on grade 3 ½
3m
center of attention = f/8 @ 2.20min on grade 3 ½
pass on = f/8 @ 1.30min on grade 3 ½
Results
0.45m
At f/2 in the centre of the image I feel there is poor resolution the letter A has soft edges which indicates aberrations are present...If you want to get a rise essay, order it on our website: Orderessay
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