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I live in an area without a camera shop nearby, so I can't see for myself.

On a DSLR, is the effect of a fisheye lens visible in the optical viewfinder or do I need a fisheye viewfinder for that? Is the fisheye effect visible in Live View?

Live view should be OK, however after searching the web I can't find sources which confirm this.

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On an SLR, since the image is transmitted by the attached lens regardless of whether you use the optical viewfinder or live view, both live view and the optical viewfinder will show what the sensor sees, including the effect of any filters or modifiers attached to the lens. Indeed, live view is a feed directly from the sensor.

Not all viewfinders offer 100% coverage of the sensor, however. The exact coverage will be listed in the camera's technical specifications, so if your camera shows less than 100% coverage you will need to check for objects intruding on the very edges of the frame that may not be visible when you frame the shot using the viewfinder. There may also be vignetting which will not be visible through the viewfinder but which is evident in live view and the final photograph.

  • I think you're right about live view: It shows what the sensor sees, so this should include the fisheye effect. With an OVF the light doesn't reach the sensor, it's a through-the-lens (TTL) view. Does TTL show the fisheye effect too? – Axel Vercauteren Feb 25 '15 at 17:01
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    Yes, the whole point of an SLR viewfinder is to show what the sensor will see. The mirror in front of the shutter is angled at 45° to enable this to happen, and the pentaprism or pentamirror inverts the image (which would otherwise be upside-down, as it is on the sensor) so that it appears upright. – NickM Feb 25 '15 at 17:05
  • I don't think so. See also link Light is bent via a mirror from the lens, up through a focusing screen, and projected to your eye via a pentamirror or pentaprism. The light does not reach the sensor. – Axel Vercauteren Feb 25 '15 at 17:43
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    It won't REACH the sensor, but it is the same as what the sensor will see. Any fish-eye effects caused by the lens will be visible in the same way. – NickM Feb 25 '15 at 18:41
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    @AxelVercauteren you said it yourself: it's TTL, through the lens. The "fisheye" effect is nothing else but how light that goes through the lens is modified by that lens. And because the light that reaches the viewfinder goes through the lens, it will have the effect. To put it simple: ttl and "having/showing the effect" are one and the same thing. – null Feb 25 '15 at 19:57
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As with any lens on a dSLR, the viewfinder and liveview will show you any lens effects. The lightpath into the camera travels through the lens first before it is reflected by the mirror up into the viewfinder, or (in liveview as the mirror is locked up) before it hits the sensor to be turned into image signals that are sent to the LCD. So however the lens has affected the light appears in the viewfinder or liveview. This is kind of the point of SLR cameras--what you see is what you get. Viewfinder coverage may not be 100% of the scene, so the edges of where the image are may be farther out than you're seeing, but overall, it'll look like the image you take.

This is no different with a fisheye than with a rectilinear lens. And AFAIK, there is no such thing as a fisheye viewfinder add-on.

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