christopher_giglio

I've seen some questions and answers regarding how to calculate

lighting ratios, but I'm a little unclear on where to point the

incident meter when dealing with a hair light or a kicker: if I want

the hairlight to read one stop over key, for example, to measure the

hairlight, do I point the dome directly back at the light (the base

of the dome is pointed away from the camera) to measure the light

output of the lamp, or do I point the dome directly upwards (in other

words, the base of the dome is parallel to the floor) over the

subject's head to measure the light falling on the hair, or do I

angle the dome towards the camera to get a sense of the light

reflected back to camera? I've read some discussion of the relation

between key and fill, but I'm not sure how to apply the theory to

light which illuminates the subject from a more extreme angle. Thanks

in advance.

Chris

Thanks for all the helpful responses. Over the past week, I've shot

about 20 rolls of film with this lens, with special attention to

backlit subjects, at varying magnification ratios and apertures. I

haven't printed anything yet, but so far, I've seen no effect of the

chip when examining the film with a loupe. I've tested the lens as is

-- that is without blackening out the chip. I was able to purchase

the lens at a very reasonable price because of the defect. So, so far

so good.

A follow up question to check if an inference I made makes sense: as

a lens projects a circular image, the edges of which are cropped by

the square format, a defect near the perimeter of lens might not

project within that square. If that is true, then from what I've read

here, it seems the only danger associated with a chip near the

perimeter is the chance of unpredictable diffraction sending light

back into the square. Thanks again for all feedback and suggestions.

I recently purchased a used Hasselblad 120 Makro with a chip on the

exterior surface of the rear lens element. It is appx. .75mm in

diameter and located about 5mm from the outside edge of the lens.

Everything else about the lens seems OK. I shot a test roll of a gray

ground at varying apertures in order to see some evidence of the

defect, but I couldn't detect anything in the chromes. Any

suggestions on other methods of testing the lens? Backlighting, etc.?

If there is no visible eveidence of a defect in lens quality, are

there other problems that might be associated with a chip? Thanks.

Thanks for your response, but what I've noticed is that some books

describe a 10 zone range of densities, with 0 being maximum black and

IX paper white; while other books describe an 11 zone density range,

from 0 as maximum black to X as paper white. I'm wondering how to

reconcile this.

Chris

I've read several books dealing with the Zone System. Some describe densities as falling from Zones 0-IX, while others range from 0-X. The longer scale includes an "extra" zone in the light areas, giving an inclusive range of 6 Zones with full detail; while the shorter scales indicate a subject brightness range of 5 as normal. Which is more useful and why is there a difference? I'm guessing that the 0-IX system is older and perhaps the 0-X system takes into account greater highlight separation of newer emulsions. If anyone knows the answer, I'd greatly appreciate it. Thanks.

Chris