offby1

Thanks for your quick responses! I think Adam got it: when I _don't_ use the flash meter, and instead simply take a picture, it works exactly as it should.

Oh, and in case you were wondering: yes, I checked the manual; it's useless, like most manuals.

I notice that my D200 has a bunch of options for controlling the built-in flash:

menu entry e3 lets me choose between TTL, Manual, Repeating Flash, and Commander

Mode. (I think TTL is the default.) Anyway, I've got it in Manual mode, and I

thus have eight further possibilities: full power, 1/2 power ... etc, all the

way down to 1/128th power. Great! However, fiddling with the menu in order to

control the power is kind of inconvenient, so I figured that I could use the

wheel and the, uh, little button (sorry, I don't know the proper terminology) to

control the power: I press and hold the little button, then turn the wheel, and

on the LCD panel on top I see the lightning-bolt symbol next to a +/- symbol,

and the number of stops by which I'm offsetting the flash power (ranging from

-3.0 stops to +1.0 stops). Here's the thing, though: that control seems to have

no effect on the flash's power. I measured with a flash meter, and it's always

full-power.

 

Now I'm not even sure that control does has any effect when the flash is in TTL

mode, either.

 

Anyway, does anyone know how it's supposed to work?

Your guess about the Gimp is correct. And you're also right to worry that selecting the dancer will be tedious. It takes a fair amount of practice. Play with the various selection tools, and read the manual sections about selecting -- there are a lot of options.

Out of curiosity, I calculated the hyperfocal distances for my lenses,

and then compared those calculated values with the depth-of-field

indicators on the lenses. (That is, I focused the lens at infinity,

and then estimated the distance that the f/16 mark was pointing at.)

I tried this with four lenses, and on three of them, my calculated

number seemed to agree with what I read off the lens; but on the other

lens, the value was way off. Why might this be?

 

<p>

 

Here's the details. I used this formula to calculate the hyperfocal

distance:

 

<p>

 

hyperfocal-distance =

(focal length squared)

divided by

(f-number times circle-of-confusion-diameter)

 

<p>

 

I used f/16 as the f-number, and 0.03mm as the circle of confusion

diameter, in each case. So my formula simplifies to (focal length

squared) divided by 0.48 mm.

 

<p>

 

My lenses are

 

<p>

 

Nikkor 20mm f/2.8 AF

Nikkor 50mm f/1.8 AF

Nikkor 85mm f/1.8 AF-D

Nikkor 105mm f/2.8 Micro

 

<p>

 

the hyperfocal numbers I got are (rounded a little)

 

<p>

 

800mm

5200mm

15000mm

23000mm

 

<p>

 

It's the third one (the 85mm) that doesn't fit; looking at the lens,

it appears that the hyperfocal distance is closer to 8000mm.

 

<p>

 

So there you have it. Might there be something about the design of

the 85mm lens that renders the formula invalid, or am I missing

something?