The Photography Discussion Thread

[NSXType-R]

Question- I know ISO is film speed, but what does that mean? Is it the speed in which the film picks up light? I don't quite understand it.

Also, when you want a "fast lens" how exactly are you supposed to know how fast it is? The price is probably one aspect of it, but what about the rest?

[2ndclasscitizen]

ISO is the sensitivity of the film. A lens' "speed" comes from what its largest aperture setting is, i.e the lower the f number, the faster the lens.

[NSXType-R]

Originally Posted by 2ndclasscitizen

ISO is the sensitivity of the film. A lens' "speed" comes from what its largest aperture setting is, i.e the lower the f number, the faster the lens.

Ok, I get the lens speed then.

But film sensitivity- the higher the ISO number, the more sensitive it is?

Which is why night photography is usually high ISO?

Then it gets grainy right?

Thanks for the answers.

[Gt1Street]

Originally Posted by NSXType-R

Ok, I get the lens speed then.

But film sensitivity- the higher the ISO number, the more sensitive it is?

Which is why night photography is usually high ISO?

Then it gets grainy right?

Thanks for the answers.

When the camera is on auto it will always try to set itself for the fastest shutter time, and when aperture and F settings are no longer shortening the time it will change the ISO setting because at higher ISO settings it requires less light for shorter periods. and this higher ISO rating causes in most cameras to a graining effect. it usualy becomes noticable and bad at ISO 800 and higher

[NSXType-R]

Originally Posted by Gt1Street

When the camera is on auto it will always try to set itself for the fastest shutter time, and when aperture and F settings are no longer shortening the time it will change the ISO setting because at higher ISO settings it requires less light for shorter periods. and this higher ISO rating causes in most cameras to a graining effect. it usualy becomes noticable and bad at ISO 800 and higher

Gotcha. So the higher ISO speed gives grain because the film doesn't have time to pick up all the details.

[90ft]

How does that work in Digital cameras then.

[Matra et Alpine]

Originally Posted by NSXType-R

Gotcha. So the higher ISO speed gives grain because the film doesn't have time to pick up all the details.

Kind-a ... the higher speed films actually use larger grains in the emulsion to capture more of the light.

Digital cameras are different. They use the same ISO numbers that photographers are used to but the results from their graininess has to do with the rate of up-take of charge on the individual pixels in the sensor and electrical/thermal noise.

[NSXType-R]

I see.

Makes more sense now.

[90ft]

I'm still not quite with it. With high ISO film the grains are larger that I get but in DIgital . .
when you take a digital image with a high ISO rate the image will have the same resolution as a low ISO image but there is a grain because . . . .

[NSXType-R]

Originally Posted by 90ft

I'm still not quite with it. With high ISO film the grains are larger that I get but in DIgital . .
when you take a digital image with a high ISO rate the image will have the same resolution as a low ISO image but there is a grain because . . . .

the sensor had less time to process the same image.

Or that's my understanding of it.

[2ndclasscitizen]

Originally Posted by 90ft

I'm still not quite with it. With high ISO film the grains are larger that I get but in DIgital . .
when you take a digital image with a high ISO rate the image will have the same resolution as a low ISO image but there is a grain because . . . .

Because the pixels are more sensitive, so they are interfering with each other, and picking up more random light. The 1st reason is why larger sensored digi's like the 1D series, D3 etc etc have better quality images. Their pixels are less dense, and therefore interfere with each other less.

[NSXType-R]

Any tips/recommendations on cleaning dust from the sensor? I got a pretty big spec of dust on my Nikon D40 and it's really bugging the crap out of me.

What equipment should I be investing in?

Thanks in advance!

[trickz]

guys....how can you do something like this?

platou_pref_curb.jpg (image)

[NSXType-R]

I don't know for sure, but you would need to take multiple pictures and stitch them together with a program, probably photoshop or gimp.

[LeonOfTheDead]

AFAIK the Nikon D40 kit doesn't support not motorized lenses, right?
but, if I use a motorized one from another maker, like a Tamron lense, using an adapter, will it still work?
and, in case of a not motorized one, does motorizing adapter or something similar exist?
thanks