Ok,
The numbers you are referring to are shutter speeds-
B stands for "bulb" and it is behaving correctly, and is for making long exposures, for example on a tripod at night where your exposure might be 15 seconds or something. A tripod and a cable release would let you accomplish an exposure like this without the camera wiggling.
1 means 1 sec
2 means 1/2 sec
4 means 1/4 sec
8 means 1/8 sec
and so on down to 1/2000 sec
If you wish to make your stop of 4.5 the priority setting, ie you are choosing that stop for some reason (in your case you have wanted a pronounced bokeh effect) then you would adjust the shutter speeds to get the green light. What need to do is get the correct
shutter speed/
aperture combination for the ISO of your film. When you adjust the ISO setting to something other than the speed of your film, you are just lying to the camera about the films sensitivity to light. (ISO refers to the films sensitivity, 50 ISO 1/2 as sensitive as 100, 200 is twice as sensitive as 100, and so on,
1/2 and double are what stops, film speeds, and shutter speeds are about, so 400 ISO
is 2 stops more sensitive, or as we say, faster than 100) So if you are shooting 400 speed film the ISO needs to be set on 400, and stay there. The shot that turned out was a happenstance. There are films that have ISO's don't exactly correspond like 320 for example, but don't worry about them right now. Also you will run across the acronym "ASA" at some point. ASA and ISO mean essentialy the same thing.
Advanced photographers sometime rate film at different ISO's than the box speed, but at this stage of the game for you, consider it non negotiable, later as you begin to understand exposure, you can develop your own film speeds.
For now, set your ISO to the box speed and adjust your exposure with shutter speed and /or aperture to get the green light.
Also, on APUG its not cool to photoshop a picture to "black and white"
. If you want to shoot black and white, use black and white film. Since you don't have a darkroom (yet)
, you can use a C41 process B&W like IlfordXP2 or Kodak PortraNC. Those films can be processed and printed just like color negative film.
You will find that there is a gulf of difference between B&W and a digitally desaturated color image, which is not B&W at all, but desaturated color. (for example with many B&W films red might expose as black, but with digital (blrgg gghhh, threw up in my mouth a little) desaturation it will be light gray. This is because black and white films render tones more according to spectral sensitivity(color), rather than lumenance(brightness) although both factor in.
The general rule on APUG is that you can use photoshop to clean up a scan, and tweak it to look the as close to the print as possible, but digital manipulations that fundamentally alter the appearance of the image are not cool.
So set that ISO correctly, use your shutter and aperture to set the exposure, and shoot the next roll!!!
