What's all this about corner softness

[Rick Knepper]

Can you show me how to make them equivalent? Or do I need to shoot the scene over with a 56mm?

I did these for a 1.6x vs. FF equivalency excercise but they may have
some value here. If they don't, then please disregard.

They don't have the same FOV, thus they are not equivalent at all.

 

[Lee Jay]

Can you show me how to make them equivalent? Or do I need to shoot
the scene over with a 56mm?

In theory, you'll frame a scene depending on the scene, not the format you are using to shoot it. Therefore, you need to shoot at the same FOV when testing different formats. And yes, that means a longer focal length on the larger format camera.

--
Lee Jay
(see profile for equipment)

 

[Stovall]

--
---
****************************************

'Giving a camera to Diane Arbus is like putting a live grenade in the hands of a child.'
Norman Mailer (b. 1923), U.S. author. Newsweek (New York, 22 Oct. 1984)

 

[filp]

Sorry I don't think it's all that important in your photo's composition. Once again, the point I'm trying to make is that;

There certainly are photos that have detail in the corners, I've never said there aren't, it's that the corner detail is not really relevant to the quality of the photo as a whole. Or at least it's quite far down the list of things to think about when making the image.

If you had some amazing, inspiring photo you wouldn't show it to the world because the corners were a bit soft?

I think here it matters (at least one corner):



--
Uzi
http://www.pbase.com/uyoeli

 

[filp]

Just to reiterate the point I'm trying to make;

There certainly are photos that have detail in the corners, I've never said there aren't, it's that the corner detail is not really relevant to the quality of the photo as a whole. Or at least it's quite far down the list of things to think about when making the image.

If you had some amazing, inspiring photo, you wouldn't show it to the world because the corners were a bit soft? I would think the photo would speak for it's self, regardless.

 

[Lee Jay]

Just to reiterate the point I'm trying to make;

There certainly are photos that have detail in the corners, I've
never said there aren't, it's that the corner detail is not really
relevant to the quality of the photo as a whole. Or at least it's
quite far down the list of things to think about when making the
image.

If you had some amazing, inspiring photo, you wouldn't show it to the
world because the corners were a bit soft? I would think the photo
would speak for it's self, regardless.

I agree with you, under the condition that the corner softness that does exist is not so severe that it actually attracts your attention. It's okay for it to be ultra soft when the corners are bokeh anyway, but if there is detail there, they need to be sharp enough that you don't notice them. And that's not all that sharp.

--
Lee Jay
(see profile for equipment)

 

[filp]

At least I was articulate enough for one person to understand what I was saying

 

[FretNoMore]

Am I the only person out there who thinks that if people are spending
a lot of time looking at the corners of your photos then maybe your
subject and composition wasn't interesting enough?

Interesting composition? I don't know, you judge. Generally speaking I agree with what you're saying but sometimes the corners do matter.

• Anders @ http://www.aobild.com *

 

[joe mama]

That's at f2.8, certainly not the type of image for peeping the edges.

But, yes that was the pic.

Actually, I think it was at f / 8, but I can't be sure. It most certainly was not f / 2.8, though. Still, lots of pics on that page to peep corners, edges, and middles on.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

Please feel free to criticize, make suggestions, and edit my photos. If you wish to use any of my photos for any purpose other than editing in these forums, please ask.

 

[joe mama]

Interesting composition? I don't know, you judge. Generally speaking
I agree with what you're saying but sometimes the corners do matter.


http://www.aobild.se/imagesforforums/ZipItBlack_2806.jpg

I've not seen a more perfect example posted!

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

Please feel free to criticize, make suggestions, and edit my photos. If you wish to use any of my photos for any purpose other than editing in these forums, please ask.

 

[joe mama]

I agree with you, under the condition that the corner softness that
does exist is not so severe that it actually attracts your
attention. It's okay for it to be ultra soft when the corners are
bokeh anyway, but if there is detail there, they need to be sharp
enough that you don't notice them. And that's not all that sharp.

At least I was articulate enough for one person to understand what I
was saying

I totally agree.

--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

Please feel free to criticize, make suggestions, and edit my photos. If you wish to use any of my photos for any purpose other than editing in these forums, please ask.

 

[filp]

Congratulations, the first example posted were corner sharpness mattered, and a very clever and well executed photo.

 

[Rick Knepper]

That's at f2.8, certainly not the type of image for peeping the edges.

But, yes that was the pic.

Actually, I think it was at f / 8, but I can't be sure. It most
certainly was not f / 2.8, though. Still, lots of pics on that page
to peep corners, edges, and middles on.

When I followedd the link, I saw f2.8 in the caption and thought it was the f-stop rather than the nomenclature of the lens.

f8 huh?

 

[joe mama]

When I followedd the link, I saw f2.8 in the caption and thought it
was the f-stop rather than the nomenclature of the lens.

Not paying attention to what I wrote, eh? : ) Just kidding! Seriously. sigh

f8 huh?

I think so. That pic caused me to start a thread a while back about that point, and people told me you have to go to f / 11 for sharp corners with the 5D + 16-35 / 2.8L (that's why I think the pic was at f / 8, since I used that pic as an example).

I must say, there's a remarkable difference from f / 8 to f / 11 in the extreme corners, and minor improvement at f / 16. Check out the other test pics. Here's an example at 16mm comparing the lower left corner at f / 8, f / 11, and f / 16 (the Red Rock Canyon pic was also at 16mm, I think):

f / 8:

http://www.pbase.com/joemama/image/81177122



f / 11:

http://www.pbase.com/joemama/image/81177116



f / 16:

http://www.pbase.com/joemama/image/81177117



--
--joe

http://www.josephjamesphotography.com
http://www.pbase.com/joemama/

 

[Rick Knepper]

Can you show me how to make them equivalent? Or do I need to shoot
the scene over with a 56mm?

In theory, you'll frame a scene depending on the scene, not the
format you are using to shoot it. Therefore, you need to shoot at
the same FOV when testing different formats. And yes, that means a
longer focal length on the larger format camera.

Okay makes sense. (I couldn't step back?) I have a hardish time following the conversations so I apologize. I thought maybe one or the other image could be resized to simulate FOV. Good to know that actual optics have to play a part.

Now, on to my point. I tried to make the point in a previous thread that was closed due to the 150 limitation happening before I could post a followup.

When a guy posts a question about how his lenses will fare moving to FF from 1.6x, I think in the majority of cases, what he really (Real World) wants to know is simply how will his finite set of lenses will fare on a FF camera. He may incorrectly believe this is a case for considering two formats when it really is about a given lens. I believe the images above prove beyond a shadow of a doubt that there is nothing remotely equivalent about images shot with the same lens and recorded on different formats.

Therefore, understanding what happens when using a given lens on unequivalent formats is a logical step in the mental process. A guy ought to know there will be things happening at the edges and corners that he didn't previously notice. This doesn't negate the points you and Joe make - and make often. But since we can't turn the 35L into a 50L for the OP and why would we, then we and/or the OP are stuck with the lens as the control in testing.

 

[Lee Jay]

Okay makes sense. (I couldn't step back?)

For landscapes, that often involves falling to your death. ;-)

When a guy posts a question about how his lenses will fare moving to
FF from 1.6x, I think in the majority of cases, what he really (Real
World) wants to know is simply how will his finite set of lenses will
fare on a FF camera. He may incorrectly believe this is a case for
considering two formats when it really is about a given lens. I
believe the images above prove beyond a shadow of a doubt that there
is nothing remotely equivalent about images shot with the same lens
and recorded on different formats.

Sure, different angles of view, different depths-of-field, completely different images.

Therefore, understanding what happens when using a given lens on
unequivalent formats is a logical step in the mental process. A guy
ought to know there will be things happening at the edges and corners
that he didn't previously notice. This doesn't negate the points you
and Joe make - and make often. But since we can't turn the 35L into a
50L for the OP and why would we, then we and/or the OP are stuck with
the lens as the control in testing.

Yes...I used my 17-40L as my generic walkaround on my 20D. On the 5D, it's my specialty ultra-wide. There's certainly value in understanding how your usage is going to change when you switch to a different format.

However, most people making that jump realize this and make changes. For example, my general use walkaround is now the 24-105L on the 5D. So, the question is how does the 24-105L on the 5D compare to the 17-40L on the 20D?

Often people switch from 1.6-crop and 10-22 to full-frame and, well, something that fits their camera (17-40L, 16-35L, 16-35L II, etc.) or make other similar changes (17-55/2.8 -> 24-105L, 85/1.8 to 135/2L, whatever). Those people (and I would say that's most people that make the switch) also need to understand how their choices will affect the product - the final image viewed at final image size.

--
Lee Jay
(see profile for equipment)

 

[Clint Sanders]

The FOV has nothing to do with this subjec. The comparison is valid.

How does FOV have nothing to do with comparing edge sharpness? It's geometry.

 

[GaborSch]

How does FOV have nothing to do with comparing edge sharpness? It's
geometry

If you think they have to do something with each other, then pls explain, what.

--
Gabor

http://www.panopeeper.com/panorama/pano.htm

 

[Clint Sanders]

How does FOV have nothing to do with comparing edge sharpness? It's
geometry

If you think they have to do something with each other, then pls
explain, what.

Please explain how differing FOVs is any way comparable?

 

[wigglesworth]

......does all this mean that corner sharpness is necessary in some landscapes? I'm just wondering because all of this seems to be avoiding the original question now... oh and that being concerned with corner sharpness doesn't mean your composition is boring?
Hmmm?
and if not, isn't it reasonable to want a lens that is sharp across the frame?