The metering will be wrong, and if you use P mode or Auto mode, the exposure will come out incorrect. ISO200 is 2 stops more sensitive then ISO50 and 1 stop less sensitive then ISO400. You can manually compensate though, so say using the ISO200 and you set it to ISO50 for example, if the meter says 1/125s f5.6, you can set 2 stops down to 1/125s f11, then the exposure would be correct... but why do you wanna do such "ma fan" thing? Need some mental exercises?
Most people push, and less people pull. The process in simple terms means shooting at a particular ISO, then varying development time to achieve another ISO.
Imagine you are asked to shoot say, a concert. All you have is ISO 400 film. But you are not getting good shutter speeds and you really want ISO 800 film. So what you do is to set your camera to ISO 800. Metering will be based on ISO 800 and you are able to shoot in dim light situations.
Now, after you finish, you go to the lab then tell them to "push 1 stop". This means they will develop the film as if it's an ISO 800 film. The side effect is that you will get more grain and contrast.
Conversely, if you shot ISO400 film at ISO 100, you tell the lab to "pull 2 stops" and they will develop accordingly.
just to let everyone know, this process can be achieved with digital photography also.
Suppose you're shooting a low light event where flash is forbidden, and your maximum ISO on your digital camera is ISO 800. The camera is suggesting very low shutter speeds at ISO 800 at the biggest aperture u have (say f2.8), and u can't handhold that shot.
wat do u do?
you can switch to manual mode or use the exposure compensation dial to dial down one stop for shutter speed to the more handholdable shutter speed. Now naturally since you dial down a stop of shutter speeds, ur images are obviously going to be underexposed by 1 stop (asssuming in camera meter reading is accurate). Just keep on shooting.
When you get back home, run Photoshop, adjust curves for the first image until the image looks correct. Save the curve you just did, and then use Automate->Batch in photoshop, create an action that will apply this curve consistently across all images from that low light event shoot. If you do it right, that curve will consistently bring up all images by 1 stop. You have now effectively increased your camera's ISO at one stop to 1600. You've pushed your digital film by 1 stop.
Sometimes, depending on camera, it may be better to push low ISO to high ISO in photoshop using levels than actually shooting at the high ISO due to high level of digital noise. You will have to experiment to see which one is moer suitable for u.
The last paragraph may seem strange, until you realise that for films, it's the same. For example it has been reported that it is better to push Fuji Press 800 film to 1600, than shoot with Fuji's 1600 film - images turn out better.
Originally posted by Red Dawn The last paragraph may seem strange, until you realise that for films, it's the same. For example it has been reported that it is better to push Fuji Press 800 film to 1600, than shoot with Fuji's 1600 film - images turn out better.
Sell/give/throw away all your Kodak, especially Kodak MAX 400. That must be one of the worst, most grainy 400 films around. With the money, buy Fuji Superia XTRA400. It costs only $7 for 2 rolls of 36 exposures at Cathay. Super fine grain.
better go ISO 800......u want to freeze pple dancing....and not have blur pictures....(of course pictures depicting movement is a different story...)
Also, if u go ISO 800, EVEN if u use flash, you can retain more of the ambient light - i
m sure in a hotel ballroom, they should have soft lights that create that special atmosphere....u dunwan to spoil that with your powerful flash! the flash can easily overcome ambient light unless your ambient exposure is near optimal, and for that, you will need that Press 800.