Friedrich wrote: >I have a question concerning the AE-Lock feature on my F70. The manual >says in page number 74 that if you want to use the AE-L button, you >should select spot or center weighted metering. Does anyone understand >why? If I lock exposure on a gray-like surface, then matrix metering >should deliver the same exposure value as center weighted or spot! >And my other question is about Fuji Velvia. I've read somewhere that >this film should be rated at 64 ASA for saturation. Assuming that this >is true, should I tell the lab that I did so? Or should I let the lab >develop it like usual? Does this also apply to negatives? Will I get a >more saturated print if I rate Kodak Gold 100 as if it had 125 ASA? And >should I tell the lab about it or will the printer correct it >automatically? What are the side effects - and is it possible to obtain >more grain by doing that? Friedrich, I know nothing about the automated features of your camera, but I think I can shed some light (pun intended) on your exposure dilemma. I wouldn't expose Velvia any slower than its rated speed of 50. There is more than enough saturation at that speed. I use Velvia for situations where colors must be coaxed out of an otherwise dull scene. Even then, I shoot it at 40, overexposing it by a third of a stop to take some of the 'cartoon color' out of it. If you were to underexpose it further than the already too-fast speed of 50, you would not want the lab to compensate for your choice by push developing it, which would defeat your purpose. Therefore, you would have the lab develop it normally. Negative film reacts in the oposite manner from slide film. It works best if overexposed by one, or even two, stops. Negative film has a very long latitude on the overexposure side, but very little on the underexposure side. One could rightly say that most color negative films (and I dare say, black and white neg films, as well) are over rated for speed by at least one stop. They are rated right on the edge of the minimum exposure required to impart the least acceptable amount of shadow detail. If you want any detail in the shadow areas of your photos, it is in your best interest to overexpose the film. No amount of push development can put detail in the darkest parts of the scene. It must be put there by sufficient exposure. Underexposing color negative film (100 ISO rated, shot at EI 125, for instance), WILL result in flat, muddy, grainy prints. While the effect will be minimal at 1/3 stop underexposure, as in the above example, it will get worse at a very rapid rate as the underexposure is worsened. Underexposure results in LESS saturation when shooting negative film. To a point (1-2 stops overexposure), the only effect during printing will be added print exposure time. If overexposed too much, many automated printing machines will reject the negative and will require manual override to get a print, but the resultant print will be very good, having adequate shadow detail and excellent color. Again, there is no need to tell the lab that you overexposed your print film. The process has a broad enough latitude to cover a 1-stop exposure increase with hardly any noticible effect. Best regards, Stew -- Photo Web pages: http://www.inficad.com/~gstewart UNIX: It's not just 'User-Unfriendly', it's 'Proactively User-Hostile'! Nothing generates so much silence as confronting a person with an undeniable truth which is contrary to that person's beliefs. Manual cameras, Luna-Pro's and stick shifts.
