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06-23-2011, 04:41 PM   #31
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QuoteOriginally posted by Big G Quote
Oh stop being so pedantic and obtuse. I was only making a passing flippant remark that a T&S lens would achieve the desired effect.
Actually, you're the one who is being pedantic and obtuse. A tilt/shift lens is not a solution for me and my DA15. Fortunately, some of the responses to my original question have been helpful to me, primarily because they indicate that I am not the only one who struggles with keystoning. It is just a fact of life with wide angle lenses, and one has to pay close attention to camera orientation at the time of capture and use digital editing tools on an as needed basis.

Rob

06-23-2011, 08:07 PM   #32
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QuoteOriginally posted by GeneV Quote
Actually the answer is not "maybe" but "no." To be precise, this thread is about keystoning with the DA15, which is not a tilt and shift lens. The only choice if you need this field of view on APS-c is post processing. To my knowledge, there is no tilt or shift lens in a FL that is remotely helpful on a Pentax DSLR in the kind of space where you would use a DA15.
That may very well be, but the shift lens was developed to deal with this problem. Unfortunately, Pentax hasn't made one since the 28mm shift lens so it is a moot point given the fov on aps-c.

Last edited by Blue; 06-23-2011 at 08:16 PM.
06-23-2011, 09:03 PM   #33
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QuoteOriginally posted by Blue Quote
That may very well be, but the shift lens was developed to deal with this problem. Unfortunately, Pentax hasn't made one since the 28mm shift lens so it is a moot point given the fov on aps-c.
Yes, no shift lens has been developed for the OP's problem. It seems a wide angle shift lens for a Pentax DSLR will only exist if/when there is a Pentax full frame DSLR.

Last edited by GeneV; 06-23-2011 at 09:28 PM.
06-23-2011, 09:55 PM   #34
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QuoteOriginally posted by paperbag846 Quote
I guess the point is, the only "natural" way to take a photo of a building with parallel lines is to hover exactly in front-centre of it...
Close, but not quite. In order to prevent convergence, the film plane must be parallel to the subject. Adding vertical shift allows you to fit a somewhat taller subject for a particular camera position, but the it is still fairly limited.


Steve


Last edited by stevebrot; 06-23-2011 at 10:08 PM.
06-23-2011, 10:07 PM   #35
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QuoteOriginally posted by robgo2 Quote
It is just a fact of life with wide angle lenses, and one has to pay close attention to camera orientation at the time of capture and use digital editing tools on an as needed basis.
I will take a turn at being pedantic and obtuse. Keystoning is a fact of life with ALL lenses. It is just more noticeable with wide angles. The key is to be aware of your camera orientation relative to the subject. There is a reason why view camera photographers level/true the camera on setup before applying any other adjustments.

As noted above, a significant amount of correction can be applied in PP. I use PT Lens for that task.


Steve
06-23-2011, 10:59 PM   #36
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QuoteOriginally posted by Big G Quote
Oh stop being so pedantic and obtuse. I was only making a passing flippant remark that a T&S lens would achieve the desired effect.
And cost at least twice as much. And be larger and heavier. And, and, and...
06-24-2011, 04:30 AM   #37
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QuoteOriginally posted by robgo2 Quote
Actually, you're the one who is being pedantic and obtuse. A tilt/shift lens is not a solution for me and my DA15. Fortunately, some of the responses to my original question have been helpful to me, primarily because they indicate that I am not the only one who struggles with keystoning. It is just a fact of life with wide angle lenses, and one has to pay close attention to camera orientation at the time of capture and use digital editing tools on an as needed basis.

Rob
No, I am not being pedantic or obtuse in the slightest.

There has already been a lot of very good advice on this thread about correcting in PP, so why repeat what has already been said? Your options in PP are to use the 'free transform' tool and 'stretch' the image to correct for this, or use Photoshops in built distorition correct. I can even post a tutorial if you like as I do a lot of this kind of work.

As I have a vast experience of this, my contribution to the thread is that if you're serious about it enough, then you may want to consider a T&S setup - how is that being obtuse? I am merely offering advice based on experience. I appreciate that this thread is specific to the DA15, but there is nothing wrong with sharing experiences or advice.

You guys need to get off your high horses and the calm yourselves.
06-24-2011, 05:03 AM   #38
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QuoteOriginally posted by deadwolfbones Quote
And cost at least twice as much. And be larger and heavier. And, and, and...
and is nonexistent in any useful FL for Rob's camera ....


Last edited by GeneV; 06-24-2011 at 05:14 AM.
06-24-2011, 05:30 AM   #39
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QuoteOriginally posted by stevebrot Quote
I will take a turn at being pedantic and obtuse. Keystoning is a fact of life with ALL lenses. It is just more noticeable with wide angles. The key is to be aware of your camera orientation relative to the subject. There is a reason why view camera photographers level/true the camera on setup before applying any other adjustments.

As noted above, a significant amount of correction can be applied in PP. I use PT Lens for that task.

Steve
Very true, Steve, and nothing pedantic or obtuse about your post. Perspective (and plane of focus) adjustments have been true joys of getting a view camera--even a field camera with limited movements. That is not all that helpful to the OP's issue with a Pentax DSLR, but is a fascinating subject.

I think Paperbag is just talking about the next step after leveling. If you can't get the building in view with the fixed lens you have without tilting the film plane, your only choice is really to elevate to a location where you can get the entire subject in view while the film is parallel to the subject, or correct with PP. The former is not really practical in most cases.

Last edited by GeneV; 06-24-2011 at 05:56 AM.
06-24-2011, 05:50 AM   #40
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QuoteOriginally posted by Big G Quote
No, I am not being pedantic or obtuse in the slightest.

There has already been a lot of very good advice on this thread about correcting in PP, so why repeat what has already been said? Your options in PP are to use the 'free transform' tool and 'stretch' the image to correct for this, or use Photoshops in built distorition correct. I can even post a tutorial if you like as I do a lot of this kind of work.

As I have a vast experience of this, my contribution to the thread is that if you're serious about it enough, then you may want to consider a T&S setup - how is that being obtuse? I am merely offering advice based on experience. I appreciate that this thread is specific to the DA15, but there is nothing wrong with sharing experiences or advice.

You guys need to get off your high horses and the calm yourselves.
[High Horse]Most of us on this forum try our best to share our experience ("vast" or not) without condescension or insult. We are just trying to be helpful to the question asked. Once anyone starts down the road of characterizing someone else's posts in a negative way, helpfulness suffers. [/High Horse]

Last edited by GeneV; 06-24-2011 at 10:12 AM.
06-24-2011, 09:13 AM   #41
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QuoteOriginally posted by stevebrot Quote
Close, but not quite. In order to prevent convergence, the film plane must be parallel to the subject. Adding vertical shift allows you to fit a somewhat taller subject for a particular camera position, but the it is still fairly limited.


Steve

I believe that if we extends things to the extreme, that lens shift is superior to hovering at the midpoint of a tall edifice. If we stood at the base of a 100 mile high building, we could, with a lens of sufficient coverage, make an image with parallel lines. If, however, we hovered 50 miles above the base of this building and used a non-shifting lens, the image would show the building edges converging in both directions in a very long diamond shape.
06-24-2011, 10:43 AM   #42
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QuoteOriginally posted by Big G Quote
No, I am not being pedantic or obtuse in the slightest.

There has already been a lot of very good advice on this thread about correcting in PP, so why repeat what has already been said? Your options in PP are to use the 'free transform' tool and 'stretch' the image to correct for this, or use Photoshops in built distorition correct. I can even post a tutorial if you like as I do a lot of this kind of work.

As I have a vast experience of this, my contribution to the thread is that if you're serious about it enough, then you may want to consider a T&S setup - how is that being obtuse? I am merely offering advice based on experience. I appreciate that this thread is specific to the DA15, but there is nothing wrong with sharing experiences or advice.

You guys need to get off your high horses and the calm yourselves.
If I misjudged you, then I apologize, but it did seem that recommending a T/S lens was not a practical solution to my problem.

As stated previously, the Keystone Correction tool in Capture One 6 is the best software solution that I have found. Not only does it correct converging lines by the "proper" amount, but the tool also has an Aspect Adjustment slider that allows you to fix the distortions introduced by the correction itself. I am referring to the squat, scrunched-up appearance that often results from making converging lines more parallel. C1 lets you "stretch" the image in whatever direction you want to restore a normal sense of proportion.

I realize that few people on this forum use Capture One, but it is an amazing program that produces gorgeous images with great ease.

Rob
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