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Author Topic: Canon 17mm TS lens - first images  (Read 11550 times)

Cineski

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Re: Canon 17mm TS lens - first images
« Reply #20 on: May 23, 2011, 06:39:59 pm »

How is that silly?  A 17mm 35mm equivalent field of view on a 645 medium format is approx (I know not exactly) a 35mm lens so you get 35mm distortion levels with a 21mm (35mm equivalent) field of view.  On 4x5 it's approximately a 45/50mm lens.  Slap my 24mm on my 35mm and take a full body shot up close gives unnatural distortion.  Slap a 45mm on my 645 and get the same shot/framing and it looks much more natural despite the same field of view and distance to subject.  Bringing tilt/shift into a 17mm lens on 35mm just looks outrageous.  Yes, there's a time and place for it, but not for any type of accurate representation.
« Last Edit: May 23, 2011, 06:41:45 pm by Cineski »
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Cineski

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Re: Canon 17mm TS lens - first images
« Reply #21 on: May 23, 2011, 06:50:12 pm »

Those are some good points for usage which I had not thought of.  I just tend to prefer a more natural looking image.  I cringe when I see 17 tilt shift images like those posted.  Just my preference.  If it's used with deliberate intention that's different than using it simply because it subjectively looks cool ;-).


You have a point, but then a lot depends on intended usage. For many outlets a pretty dramatic perspective, with good verticals, can really add something to a subject. I can see a lot of travel publiction useage for things like that, stock etc. as well as some estate agents fighting to show a facade in these crowded tourist zones, but I wonder if architects themselves are all that keen. I have no idea about that, I just wonder what they think about it. I would certainly like such a lens. Being Nikon, I can safely say that and know I'm not going to have to do anything about it!

Rob C
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mediumcool

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Re: Canon 17mm TS lens - first images
« Reply #22 on: May 23, 2011, 06:51:37 pm »

I agree that over use of extreme wide angle lenses is a problem and IME is the particular issue with newbies, BUT there is nothing unique about DSLRs in this regard.

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Kirk Gittings

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Re: Canon 17mm TS lens - first images
« Reply #23 on: May 23, 2011, 08:26:35 pm »

How is that silly?  A 17mm 35mm equivalent field of view on a 645 medium format is approx (I know not exactly) a 35mm lens so you get 35mm distortion levels with a 21mm (35mm equivalent) field of view.  On 4x5 it's approximately a 45/50mm lens.  Slap my 24mm on my 35mm and take a full body shot up close gives unnatural distortion.  Slap a 45mm on my 645 and get the same shot/framing and it looks much more natural despite the same field of view and distance to subject.  Bringing tilt/shift into a 17mm lens on 35mm just looks outrageous.  Yes, there's a time and place for it, but not for any type of accurate representation.

Ok thats your opinion, understand I made my living with a 4x5 and 6x9 view cameras shooting film on architecture for 30 years (and continue now with digital) and am very aware of what super wide lenses do on various formats, and also know that some of the top architectural photographers in the world routinely use that 17 lens on a DSLR quite effectively-not as a "go to" lens but a problem solver. It has a great reputation with APs, which my own tests bear out. Newbies get seduced by the super wide angle "look" which becomes a "too" easy and ultimately saccharin compositional tool-regardless of how the image relates to the architecture.

I think it is likewise silly to make a blanket statement about a piece of equipment for a whole genre of photography based on some amateur pics.

Personally I don't own the 17, but have tested a couple. If I had a surplus of cash I would buy it, but can't justify it in this economy as little as I would use it. I solve the same problem with a simple flat stitch with the 24 II T/S. But I own and use a 47XL for use on my 4x5. Such lenses are very useful when you are backed into a corner and can't use a more normal lens.
« Last Edit: May 24, 2011, 12:57:11 am by Kirk Gittings »
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Kirk Gittings

Robert DeCandido PhD

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Re: Canon 17mm TS lens - first images
« Reply #24 on: June 22, 2011, 12:50:18 pm »

Some info on this lens - see discussion about corner softness when tilting:

http://www.fredmiranda.com/forum/topic/1020683
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Kirk Gittings

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Re: Canon 17mm TS lens - first images
« Reply #25 on: June 22, 2011, 01:00:48 pm »

If thats a design problem it is unfortunate, but I am wondering how much you really need tilt on that lens? I rarely need it on my 24 and the 17 will have substantially more DoF than my 24 at a given aperture.
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AFairley

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Re: Canon 17mm TS lens - first images
« Reply #26 on: June 22, 2011, 06:06:51 pm »

My take on the photos is that the geometry doesn't look quite right, but I think it's the lens's native geometry, not tilts or shifts.  (I've used 28mm and 35mm shift lenses in film days and shot architecture with 4x5 so I know about shifts and tilts).  It's like there's some lens distortion in there that hasn't been cleaned up (barreling?  complex waveform?)  It just looks a little odd.  (I'm not familiar with this lens, so don't know its native geometry)  I am not an HDR fan, so won't comment on the overall look of the photos, to each his own....
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stewarthemley

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Re: Canon 17mm TS lens - first images
« Reply #27 on: June 23, 2011, 04:28:45 am »

If thats a design problem it is unfortunate, but I am wondering how much you really need tilt on that lens? I rarely need it on my 24 and the 17 will have substantially more DoF than my 24 at a given aperture.

I am often amazed at how little tilt is needed to correct even large differences in near/far focus distances. For both my 17 and 24 mk 2's I have yet to use more than one "notch" on the lens marking (I believe in using very technical terms when I can...). Also, of course, this allows extreme OOF shots if that's what you want. These are incredible lenses and compare extremely well with the R's and S's. If you don't believe me, try it and be amazed.
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Bart_van_der_Wolf

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Re: Canon 17mm TS lens - first images
« Reply #28 on: June 24, 2011, 06:37:56 am »

But that is silly. You can just as easily put an ultra-wide lenses on a large format view camera or medium format and get exaggerated perspective and field of view.

I agree that over use of extreme wide angle lenses is a problem and IME is the particular issue with newbies, BUT there is nothing unique about DSLRs in this regard.

Hi Kirk,

I absolutely agree. The trouble is that most newbies (and even a fair number of old farts) do not grasp that the issue is not really in the lens. Whether one uses a DSLR with a short focal length, or a DSLR with a longer FL with stitching, or a view camera, makes no difference for the 'look' if one captures an identical field of view and uses a rectilinear projection on the resulting image plane.

The (ultra)wide-angle 'look' comes from viewing the resulting image from a distance that's too far away for the focal length used. For a 'natural' look, one needs to view the image from a distance that's proportional to the FL used to record it (and from the bottom of the image in case of high buildings). That may require a wide angle shot to be viewed at an uncomfortably short distance, thus we tend to view it from farther away, and there the cognitive unease is created.

As an example, the shots with a 17mm FL on a 36mm wide sensor array, need to be viewed at a 300mm / 17mm = 17.65x output magnification if we want to view it from 300mm for an identical projection as our lens. So our output needs to be something like 36mm x 17.65 = 635 mm (25 inches) on the long side for normal reading (300mm) distance viewing. When we look at a smaller version on a web page, e.g. 7 inches (177.8 mm) on the long side, we'd need to look at it from an even more uncomfortable 84mm distance to keep the projection identical to the lens/sensor projection. Because we look at it from farther away, the vanishing points from the viewing position don't agree with the projection anymore. That's where the wide-angle 'look' comes from.

The 17mm (or equivalent FLs on other formats) is helpful if confronted with tight spots, or when one deliberately wants to exagerate the spaciousness, because the output will almost always be viewed from 'too far away' for the projection used to look natural.

The same principle of anamorphic projection perspective applies to e.g. signs painted on the road, or street drawings, they need to be viewed from exactly the correct (projection) position to look natural. Any deviation from the ideal position and things start looking 'unnatural'.

Cheers,
Bart
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