Thamnophis
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Do adapters reduce the light hitting the sensors, as extension tubes do? Will they turn my f1.4 lens into an effective 2.0 for example?
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Do adapters effect exposure?
- Thread starter Thamnophis
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Letsgokoulos
Senior Member
No. The adaptors are hollow tube that replace the mounting flange. There is no loss of light.
Marc
TiagoReil
Senior Member
For the LAEA2 yes
The rest no
About your lens. The adapter wont turn your f1.4 into an effective f2, but the sensor may.Sensors are not as effecive as they should with fast lens, so the 1.4, in terms of light (not of DoF) may become something like a 1.7
El Matadurr
Veteran Member
Addendum: this applies to modern sensors as a whole, not just our APS-C NEXes. The limiting factor is the f/stop of the microlenses on each pixel.
matthewdurrphotography.com
Thamnophis
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But...
"Their only real drawback with tubes is that there is a loss of light and this increases the more extension you add."
from: http://www.macrobellows.com/using_tubes.php
If you google "extension tube exposure" you'll see there seems to be wide agreement that extension tubes actually do effect exposure.
Don't adapters do the same?
Joe
"Their only real drawback with tubes is that there is a loss of light and this increases the more extension you add."
from: http://www.macrobellows.com/using_tubes.php
If you google "extension tube exposure" you'll see there seems to be wide agreement that extension tubes actually do effect exposure.
Don't adapters do the same?
Joe
TiagoReil
Senior Member
Yes, but the extension tube is putting your lens in a farther distance that it should be. An adapter, is putting the lens at the exact distance it should be, designed by the manufacturer. So you are not loosing light.
They may look the same, an adapter, and an extension tube, but they are not. The adapter puts the lens where it should be. The extension tube puts the lens farther than where it should be. So the first one works as designed, so no loss of light. The second one doesnt, so you have the loss of light.
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Photozopia
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You are confusing extension tubes with a simple tubular adaptor that merely spaces a 'non-original' lens the correct distance (i.e. the 'register' it is designed for) from the sensor. No mathematical extension of light path = no decrease in light value.
No they don't - extension tubes do indeed affect light/exposure as well as introduce distortions, yes, but the basic NEX adapter positions the lens at the correct distance from the NEX sensor (which is the exact same distance the lens was from the film on the camera it was originally designed for*), with no loss of light/exposure.
*note - these cameras were thicker than the NEX, which accounts for the adapter thickness
Thamnophis
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Ah, I get it now. Thank you.
No, because when you use an adapter the lens ends up at its normal distance from the film or sensor, focussed at infinity.
The distance from a Nikon lens, for example, to the sensor is exactly the same on a Nikon DSLR or on a NEX-with-adapter.
If you then add an extension tube, the lens will be focussed close up, the image will be spread over a larger area, and the exposure will need to be increased.
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