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Pentax 645D vs S2

R

RKLFteacher

Guest
Schneider is porting the new MF Tilt/shift to the S2 Leica in the spring.
Might help those S2 people who would like movements.
 

Mike M

New member
I don't have any philosophical objection to cropping images, mind you, but it just doesn't seem to work very well for me.
A lot of times people will develop preferences in the arts based on intuition. So it's often difficult to explain exact reasos for likes/dislikes. I have actually developed a philosophy against cropping because it shifts the lens axis plane within the frame of the image. People that have a background in drafting might get sense of disoriented perspective when viewing certain cropped images. But it's more a "feeling" than anything else...there's no real "right or wrong."

An example of this phenomenon might be to imagine an architectural exterior photograph taken of a tall building using an extreme wide angle lens with a large shift movement. Even though the horizontal and vertical lines of the building are perfectly corrected with the shift movement, the building will still "feel" top heavy to many viewers. That feeling is created because the position of the lens axis plane is low within the frame and it adds a sense of uneven weight distribution to the building . It's a psychological thing...a matter of perception. It's not necessarily right or wrong, just a feeling.

Anyhow, I try to avoid anything other than very minor cropping because of how it can add a sense of uneasiness. OF course, some artists might intentionally want to create a sense of unease depending on context LOL So there are no right or wrongs...just preferences
 

bensonga

Well-known member
A lot of times people will develop preferences in the arts based on intuition. So it's often difficult to explain exact reasos for likes/dislikes. I have actually developed a philosophy against cropping because it shifts the lens axis plane within the frame of the image. People that have a background in drafting might get sense of disoriented perspective when viewing certain cropped images. But it's more a "feeling" than anything else...there's no real "right or wrong."

An example of this phenomenon might be to imagine an architectural exterior photograph taken of a tall building using an extreme wide angle lens with a large shift movement. Even though the horizontal and vertical lines of the building are perfectly corrected with the shift movement, the building will still "feel" top heavy to many viewers. That feeling is created because the position of the lens axis plane is low within the frame and it adds a sense of uneven weight distribution to the building . It's a psychological thing...a matter of perception. It's not necessarily right or wrong, just a feeling.

Anyhow, I try to avoid anything other than very minor cropping because of how it can add a sense of uneasiness. OF course, some artists might intentionally want to create a sense of unease depending on context LOL So there are no right or wrongs...just preferences
Mike,

I just don't understand this at all, which probably exposes my limited technical understandings (no surprise here).

If I am using a camera that shoots 6x6cm format negs and another that shoots 6x4.5cm negs and have comparable lenses mounted on each (similar FOV etc)....what difference does it make if I crop the 6x6cm image down to what the 6x4.5cm image looks like? That's always been a major appeal for me of the 6x6 square format (whether with my older Mamiya TLR or newer Hasselblads), since I'm not particularly wedded to square format images....but I can crop horizontal or vertical and get the equivalent of my Pentax 645. And I've never concerned myself too much with cropping a little off the top, sides or bottom of my Pentax 67 images (especially if there is more sky etc than I really wanted), to get images that print nicely on 11x17 or 13x19 paper. I've certainly never noticed any additional tension or unease in the images.

I must be missing something here, so really, help me understand what that is. Perhaps it depends on what is cropped out of an image....not the cropping itself.....that, I could understand.

Gary
 

Mike M

New member
The lens axis plane in photography is similar to the angle-of-view or point-of-view in drawing. The angle of view helps determine where lines converge at the horizon and establishes vanishing points.

The eye of the viewer can be lead around a composition according to the lines and their vanishing points. For example, most photographers are familiar with how the viewer's eye is drawn to the lightest parts of an image and many will add vignettes in order to darken the edges and lead the viewer's eye towards the center of the frame. But lines also lead the viewers' eyes in a composition. If the lens axis plane points to the center of a frame then the lines created by it and their associated vanishing point are leading the viewer's eye to the center of the frame too.

Let's take Gary's example of shooting a 6x6 piece of film and cropping it down to the equivalent of 6x4.5 piece of film. If he were to shave off 1.5 from one side of the film then that would shift the lens axis plane away from the center of the frame and closer to the side that was cropped. However, if he were to shave .75 from the top and .75 from the bottom then the lens axis plane would remain in the center. Whether or not that is good depends on the image. But most people that crop aren't even aware of what effect it might have on perspective at all so they are usually doing a sloppy job of it.

One of the things that can confuse photographers about discussions regarding perspective is that they tend to only relate it to straightening out converging horizontal and vertical lines. So it can be a bit hard to talk about and I don't bring it up much.
 

bensonga

Well-known member
Thanks Mike.....I'll have to mull this over, think this thru....and probably do alot more to educate myself on the more technical aspects of perspective etc before I truly understand it.

Just for the heck of it, I just took one of my Pentax 67 images that I have struggled with re cropping in different ways and posted three variations to my gallery, without re-sizing the image at all (although the Gallery thumbnails are deceptive in this regard)....so the dimensions of the key object in the photograph, a large metal box, remains unchanged. Quite a different look to this image, depending on how it is cropped (from almost a pano horizontal crop vs square vs uncropped). Getting farther off topic for this thread of course, but it gets to my viewpoint that there is nothing inherently sacrosanct about the format of the original image....whether a square, 4:3, 3:2, 4:5, 6:7 or pano format works best for any particular image is, in my view, entirely dependent on the photographer and the subject matter. I don't want to limit my vision to the image dimensions of the particular camera I happen to be using at the time I took the photograph. It doesn't happen often for me....but sometimes a square view of the world actually fits better with what I'm seeing.....even when I don't have the Hasselblad handy. In fact, for this particular image.....I think I like the square format best. If I was a purist about cropping, I suppose I could have gone home to get the Hasselblad and re-shot the image.....but would the result have been any different?

http://forum.getdpi.com/gallery/browseimages.php?c=181&userid=

Gary
 
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Audii-Dudii

Active member
The lens axis plane in photography is similar to the angle-of-view or point-of-view in drawing. The angle of view helps determine where lines converge at the horizon and establishes vanishing points.
Color me dumb, but I never thought about this before. But I find it interesting to reflect upon, as I photograph a lot of architecture, and on those rare occasions when I do crop, it's only to remove the extra bit of image that wasn't visible in the viewfinder when I framed my composition (i.e., my crops are almost always done symmetrically around the center of the image).

Perhaps this also explains why I generally prefer single-shot images to those that have been stitched together by shifting the lens instead of the back?

Hmm....
 

Mike M

New member
but would the result have been any different?

http://forum.getdpi.com/gallery/browseimages.php?c=181&userid=

Gary
Check out this graph on one-point-perspective:
http://www.olejarz.com/arted/perspective/

Notice that all of the lines at the edges of the frame converge at a single point in the center. Imagine that the center of the graph is similar to the lens axis plane placed in the center of an image. Observe that there is more space between the lines at the edges of the frame than there is between the same lines near their point of convergence. The farther the lines are from the point of convergence means the more space between them. The closer the lines are to the point of convergence means the least space between them.

OK - So how does this relate to cropping the edges of an image? Now we're going to have to go into right brained territory which is dominated by feelings and intuition. I linked the graph so that left brained analytical people can understand the concept. But in the end, the only people that will really "get it" and know how to apply it will have to "feel" it more than know it.

When a photographer crops the edges of a frame, he is eliminating the part of the image where the lines have the most space between them. The crop is now emphasizing the part of the image where the converging lines have the least space between them. This reduction in space between lines adds empasis the center of the image where the lines are closest together. This causes a "claustrophobic" type of tension in the gut of the viewer. My unofficial and non-technical name for this tension is the "Star Wars Trash Compactor Effect." ;) Remember the scene where Luke Skywalker and friends jump into the Death Star trash compactor and all of the walls slowly close in until there is no room left and they are all almost smashed? That is exactly the same kind of tense feeling that cropping the edges from an image creates in the viewer. The image is essentially losing space and being squeezed together just like a trash compactor. The greatest feelings of claustrophobia will be caused by the heaviest crops. But the tension is always there no matter how sparingly the edges may be cropped.

The best way to test this out is to shoot the same subject 2 different ways while making certain that the composition and angle of view doesn't change between shots. Obviously, one shot would be done with the camera pulled back far and then cropped heavily into the final image. The second shot would be done with the camera closer to the subject and the final image would reman un-cropped. If the photographer does a good job of maintaining the same composition and the point of view between both cropped and un-cropped shots, then the one that is cropped should feel claustrophic in comparison to the the one that is un-cropped. Disregarding any possible resolution difference in the cropped image or depth of field differences due to distance etc....both images should essentially look the same, but feel different to the viewer simply because of the difference in space between the lines in the frame.
 

Mike M

New member
Perhaps this also explains why I generally prefer single-shot images to those that have been stitched together by shifting the lens instead of the back?

Hmm....
That is an excellent example. I don't like the look of images stitched by shifting the lens either precisely because of what it does to the lens axis plane.
 

bensonga

Well-known member
Thanks for all that information and the link Mike, but this still leaves me wondering about the seemingly arbitrary (to me) aversion to cropping a image as a matter of principal. Suppose I'm shooting with my Hasselblad with one of the 6x6 cm backs attached. I take a photo (square format of course), but then decide later that this image would look better, for whatever reason, in a rectangular 6x4.5 format. Now I could have taken that same photo twice, once with the 6x6 back attached and a second time with Hasselblad's 6x4.5 back attached. If I had taken two shots, one with each back, I'd have an image that didn't need to be cropped (from the 6x4.5cm back)....but what difference does it make if I simply cropped the 6x6 to 6x4.5 (or some other dimension, for that matter)? Yes, I understand the image will look different and for many of the reasons you've noted.....but as to the actual choice between cropping an existing image (6x6) or using a camera/back that already is "cropped" to those dimensions (as with this example).....I really don't see that whether an image is cropped or uncropped makes any difference. This is why the general aversion to cropping an image, in and of itself, is not something I feel (ie the original dimensions of an image are not carved in stone for me).....it's what the final image looks like that matters, whether it's square, 4:3, 3:2, 6:7 or whatever.....and in working up an image for printing, I don't limit myself to the format of the particular camera I'm using at the time the original photo was taken.

Gary
 

Mike M

New member
@Gary
The image circle itself is a frame and the film/sensor is actually a crop from the frame, so similar ideas apply to that too. Sorry to stray OT, but I was just introducing the idea to people in case they hadn't thought of it before. That doesn't mean they'll be able to use it in their own work. This isn't left brain analytical, it's right brain intuitive. It's basically a way of associating feelings with perspective. Choice of focal length itself can have psychological and symbolic associations but I won't hog up anymore of the thread blabbing :)
 

etrigan63

Active member
Hey Mike,
don't get me wrong, the discussion was intensely fascinating, but kinda OT. It certainly deserves further discussion in it's own thread. Wish I could do something about it.
 

bensonga

Well-known member
Hey Mike,
don't get me wrong, the discussion was intensely fascinating, but kinda OT. It certainly deserves further discussion in it's own thread. Wish I could do something about it.
+1! Sorry for getting us farther and farther OT. It's given me alot to think about and a different way of looking at my choices etc....so thanks Mike!

Gary
 
K

Khaled gawdat

Guest
I used to have bronica 645 with schnieder zoom lens that gave incredible picture quality. Digital MF I choose between leica s2 and pentax 645d. The 4/3 format in pentax rather than the 3/2 format in leica was a decisive factor but more importantly the range of lenses and cost. I have now the pentax 645d with 5 autofocus lenses, 3 of them zooms for less than the price of the s2 body alone. I can be much more creative and productive this way.
 

etrigan63

Active member
The price of the Pentax 645D makes it highly appealing. The lenses are surprisingly good (to the uninitiated) and freely available on the second-hand market. In this economic climate, the 645D has some very strong points.
 

Paratom

Well-known member
I used to have bronica 645 with schnieder zoom lens that gave incredible picture quality. Digital MF I choose between leica s2 and pentax 645d. The 4/3 format in pentax rather than the 3/2 format in leica was a decisive factor but more importantly the range of lenses and cost. I have now the pentax 645d with 5 autofocus lenses, 3 of them zooms for less than the price of the s2 body alone. I can be much more creative and productive this way.
How consistent do you find the AF?
There were reports with different conclusion.
I agree that the price of the Pentax 645 is very appealing as the big range of second hand lenses.
On the other side lens quality was one of the reasons why I choose the Leica - I thought if I did I would never have to doubt about lens quality any more - and thats how I feel now.
3:2 vs 4:3 is also quite a question. I like both-depending on the subject.
Anyways-great to have those choices.
 

Shashin

Well-known member
How consistent do you find the AF?
There were reports with different conclusion.
Only one of my lenses is AF--the new 55mm. I find the AF very good. With the old AF lenses, you can adjust the AF focus point for each lens. The camera will remember the adjustment for each lens.

When I was shopping for the 645D, there were lots of reviews with different conclusions (some panning the 645D without even bothering with the formality of even using the camera--see Ken Rockwell). My conclusion is there is sample variation in products AND reviewers. Like many things, the "truth" is somewhere in between the extremes. I really enjoy this camera. It is really well designed and can give great results. Fortunately, there is enough full-size image samples on the web that can answer many questions--where I live there was no chance to try before buying.
 

tsjanik

Well-known member
I concur with Shashin. I have 5 FA lenses and have not found is necessary to input any focus adjustment. I had trouble with the manual focus lenses, consistently suffering front focus; however, once I acquired a 2x magnifier for the eyepiece that problem went away. I should say I rarely use a lens wide open and although I tested my lenses at full aperture it's not a significant aspect for me, so perhaps f/8 hides some focus errors. I followed Lloyd Chamber's review of the 645D very closely (in fact two of the lenses he tested are mine). It’s a paid site, but I don't think I'm giving anything away by mentioning that he found the AF in the S2 to be unreliable (he had similar complaints about the Pentax). Perhaps I am not as critical as he, but I’m quite satisfied. I should mention that I do not use the matrix AF; rather I lock focus using the central sensor and then recompose.

Tom
 

D&A

Well-known member
Hi Tom & All,

I would honestly have to say that AF fine tuning with some of the FA af lenses is manditory if one plans to use them at any f-stop generally below f8 (like aprox. f7.2 etc). It's at these more open f-stops that I found with the majority (although not all) FA af lenses (multiple samples of each focal length tested) needed AF fine tuning and the increase in sharpness and resolution was striking at times. This also helped with edge/corner sharpness with lenses that exhibted considerable field curvature, like the FA 35mm f2.8 lens. Yes, 100% crops of these files were examined, but this increase in sharpness, especially across the frame was needed prior to large format printing of images. Multiple samples of a given lens might sometimes needed quite diffferent Af fine tune settings. The one lens that consistantly didn't (quite a few sample tested) was the FA 120 f4 macro. I surmised this may be due to the extra care and adjusment of this particular lens by Pentax since it was a macro lens and the focusing range in a macro lens is "great", going from 1:1 macro to infinity.....therefore it had to be carefully adjusted, even for film use, before leaving the factory.

I agree with Tom...if you are going to use most of the FA lenses at f8 and especially f11, Af fine tune in most cases will have minimal effect...or if you don't examine files at 100%, or print large, then Af fine tuning may also be of lesser value.

*** I should add that I have found the Af with the 645D along with FA 645 lenses is quite reliable and very accurate "AFTER" Af fine tuning was completed. Even at a len's minimum focusing distance, focus was extremely accurate...using either the center or side sensors. Of course its not as fast as a Pro DSLR especially in tracking. nor is lock-on in certain lighting situations as predictable as a Pro DSLR, but it's capability and performance is beyond what I expected...so no complaints on my end.

Dave (D&A)
 
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