Eos 7d

[Lindseysa]

I've had my 7d for a few years and have been thinking of buying the 16-35mm f/4L lens.  As the 7d isn't full frame, will this lens work as I've heard that you can only start using it at 20mm.

Also, has anyone any feedback on the Eos 6d?  I take mainly landscape photos and work a lot in low light.  Any help would be appreciated

[TTMartin]

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@ebiggs1 wrote:

"Fish-eye lenses will have distortion that you are probably not looking for."

Yeah, just like this shot.

@Canon 7D, 8-15mm f4L @ f16, SS 1/400, ISO 100

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Yes, exactly like that one, where the tower is vertical, but the horizon is not horizontal. Which would be fine if this were a picture of the Leaning Tower of Pisa, but, it is not.

[ebiggs1]

Oh dear me.  You are too much! 

The horizon not being level is a fault by me.  Not the lens.  This is simply a snapshot and not actually designed to show anything.  But it does show you know nothing about this lens.  Doesn't it?

[TTMartin]

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@TTMartin wrote:

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@ebiggs1 wrote:

"Fish-eye lenses will have distortion that you are probably not looking for."

Yeah, just like this shot.

@Canon 7D, 8-15mm f4L @ f16, SS 1/400, ISO 100

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Yes, exactly like that one, where the tower is vertical, but the horizon is not horizontal. Which would be fine if this were a picture of the Leaning Tower of Pisa, but, it is not.

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Again, Tower is vertical, horizon is not horizontal, NOT the tower and the horizon both are tilted the same. Additionally the building on the right side of the photo tilts to the left. This is distortion from trying to computer correct lens distortion from a fisheye lens. The only user error is believing that you can simply and easily correct for fisheye lens distortion with post processing. BTW, that's an awful lot of post processing to do for a 'simple snap shot'. SMH

[Waddizzle]

Psst, Tom.  The 8-15mm Zoom Fisheye is a very unique lens.  You do not necessarily have to correct for fisheye distortion in post when you use a crop body, because the lens can correct for it when you capture the image.  The lens can function as an ultra wide zoom, or as a fisheye prime.  I keep trying to tell you that it really isn't your typical zoom lens.

[RobertTheFat]

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Waddizzle wrote:

Psst, Tom.  The 8-15mm Zoom Fisheye is a very unique lens.  You do not necessarily have to correct for fisheye distortion in post when you use a crop body, because the lens can correct for it when you capture the image.  The lens can function as an ultra wide zoom, or as a fisheye prime.  I keep trying to tell you that it really isn't your typical zoom lens.

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I guess I don't see how the lens can correct its own fisheye distortion. I could understand it if you're saying that since fisheye distortion is greatest near the perimeter, a crop camera won't see the worst of it. Then if you position the image carefully, you can toss it to Photoshop to be corrected as though it came from a really crappy rectilinear WA lens. Is that basically it? Or is that what Tom was saying, and we're both missing something?

[Waddizzle]

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@RobertTheFat wrote:

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@Waddizzle wrote:

Psst, Tom.  The 8-15mm Zoom Fisheye is a very unique lens.  You do not necessarily have to correct for fisheye distortion in post when you use a crop body, because the lens can correct for it when you capture the image.  The lens can function as an ultra wide zoom, or as a fisheye prime.  I keep trying to tell you that it really isn't your typical zoom lens.

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I guess I don't see how the lens can correct its own fisheye distortion. I could understand it if you're saying that since fisheye distortion is greatest near the perimeter, a crop camera won't see the worst of it. Then if you position the image carefully, you can toss it to Photoshop to be corrected as though it came from a really crappy rectilinear WA lens. Is that basically it? Or is that what Tom was saying, and we're both missing something?

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I have no idea how they do it, but the lens is not a fisheye throughout its' entire zoom range, only at 8mm, and even then only on a full frame body.  I have been looking at buying one because it is a super ultra wide zoom over the rest of its' range, particularly with a crop body, which i believe does not use the entire zoom range at all.  Call it 10-15mm, for argument's sake, when you use a crop body.  It has zoom stops for full frame, APS-C, and APS-H bodies.  Check out an owner's manual or a product description.  It really is not your typical zoom lens.

[TTMartin]

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@Waddizzle wrote:

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@RobertTheFat wrote:

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@Waddizzle wrote:

Psst, Tom.  The 8-15mm Zoom Fisheye is a very unique lens.  You do not necessarily have to correct for fisheye distortion in post when you use a crop body, because the lens can correct for it when you capture the image.  The lens can function as an ultra wide zoom, or as a fisheye prime.  I keep trying to tell you that it really isn't your typical zoom lens.

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I guess I don't see how the lens can correct its own fisheye distortion. I could understand it if you're saying that since fisheye distortion is greatest near the perimeter, a crop camera won't see the worst of it. Then if you position the image carefully, you can toss it to Photoshop to be corrected as though it came from a really crappy rectilinear WA lens. Is that basically it? Or is that what Tom was saying, and we're both missing something?

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I have no idea how they do it, but the lens is not a fisheye throughout its' entire zoom range, only at 8mm, and even then only on a full frame body.  I have been looking at buying one because it is a super ultra wide zoom over the rest of its' range, particularly with a crop body, which i believe does not use the entire zoom range at all.  Call it 10-15mm, for argument's sake, when you use a crop body.  It has zoom stops for full frame, APS-C, and APS-H bodies.  Check out an owner's manual or a product description.  It really is not your typical zoom lens.

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Just because the edges aren't cut off at some focal lengths like a circular fisheye, doesn't mean there isn't barrel distortion. The zoom stops you talk about are simply where the corners don't start to get cut off, NOT where there isn't any barrel distortion. 

[Waddizzle]

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@TTMartin wrote:

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@Waddizzle wrote:

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@RobertTheFat wrote:

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@Waddizzle wrote:

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Just because the edges aren't cut off at some focal lengths like a circular fisheye, doesn't mean there isn't barrel distortion. The zoom stops you talk about are simply where the corners don't start to get cut off, NOT where there isn't any barrel distortion. 

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What focal length do you think was used in Ernie's shot?  I think it is closer to the longer end, than the shorter end.  My entire point has been simple, that the lens looks very different on a crop body, compared to a full frame, and this behavior is by design.  

BTW, I made no claim that the lens exhibits no barrel distortion, just that it is very different on an APS=C body.  But, I would bet the lens has less barrel distortion than the EF-S 10-18mm zoom at similar focal lengths, on a crop body.  So, I really do not see the point of your arguments.  

[TTMartin]

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@Waddizzle wrote:

 I would bet the lens has less barrel distortion than the EF-S 10-18mm zoom at similar focal lengths, on a crop body.  So, I really do not see the point of your arguments.  

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I would take that bet, since the EF 8mm-15mm fisheye 'makes no attempt to correct the huge barrel distortion', where the EF-S 10mm-18mm IS STM and the EF-S 10mm-22mm USM are 'rectilinear'* wide angle lenses.

* a rectilinear lens is a photographic lens that yields images where straight features, such as the walls of buildings, appear with straight lines, as opposed to being curved. In other words, it is a lens with little or no barrel or pincushion distortion.

[ebiggs1]

"BTW, that's an awful lot of post processing to do for a 'simple snap shot'."

And, that is an awful lot of baloney from you, friend.  You know nothing of what you speak.  There is no post done on that shot except for the LR lens correction done on import.  And, that my friend I do on every single photo I import so it is not a singular effect done to the 8-15mil.

"I would take that bet, since the EF 8mm-15mm fisheye 'makes no attempt to correct the huge barrel distortion',"

Again, my friend, you would lose.  I believe the exif in intact with that shot.

Since you seem to be so ignorant about this lens, I again repeat this was just a snap shot.  There was no attempt to correct for anything.  I simply saw tha Mall and raised the 7D and took the shoot.

Whether you want to admit it or not the Canon EF 8-15mm f/4L Fisheye USM Lens is an amazing and unique lens. It is one of my favorite lens to play around with.  Since you never used one, you probably shouldn't try so hard to analyze it.  Hmmmm?