Adapting other lenses to GH1 - Losing light?

[DanielRutter]

Hey guys;

I was just curious, as I use mostly adapted lenses (I only own 1 panasonic lens, the 14-42) with my GH1(7). I'm curious to know if theoretically I'm losing stops of light using an adapter to attach other lenses, say a Pentax 50mm 1.7?
How does an adapter work, and what potentially can it do to an image? Am I losing a small amount of detail by using an adapter/non-Panasonic lenses?

 

[patvig]

Hey guys;

I was just curious, as I use mostly adapted lenses (I only own 1 panasonic lens, the 14-42) with my GH1(7). I'm curious to know if theoretically I'm losing stops of light using an adapter to attach other lenses, say a Pentax 50mm 1.7?
How does an adapter work, and what potentially can it do to an image? Am I losing a small amount of detail by using an adapter/non-Panasonic lenses?

Such an adapter is purely mechanical and (optionally) electrical. Because there is no optical and because the purpose of this adaptor is to keep the lens/sensor distance, there is no change in diaphragm value. So your 50 mm 1.7 will remain a 1.7 lens.

 

[DanielRutter]

Alrighty. Thanks for that Patvig. I was curious to know. So if it doesn't change that value, does it have any factor in changing focal length?

 

[Kin Lau]

Non-optical adapters do not change the focal length.

 

[Jester2138]

Alrighty. Thanks for that Patvig. I was curious to know. So if it doesn't change that value, does it have any factor in changing focal length?

Focal length is focal length is focal length and won't change just because you put the lens on a different camera. What may change is the field of view, or "crop-factor."

 

[patvig]

Alrighty. Thanks for that Patvig. I was curious to know. So if it doesn't change that value, does it have any factor in changing focal length?

The Pentax cameras have a distance between the lesn interface and the sensor greater that the *4/3 ones.
The 2 main purposes of the adaptor are :
1 to convert Pentax bayonet to µ4/ one
2 to compensate this length difference

The result is the possibility to use the Pentax lens as if it was a (manual) µ4/3 one.

It is the same with adapters for other brands.