Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-31-2015, 04:57 AM - 5 Likes   #1
New Member




Join Date: Sep 2014
Location: Zurich
Posts: 19
Wideangle shots without wideangle distortion

To come right out of the gate, let me say that "I don't like wideangle lenses". Why? Mainly it's the distortion that bothers me, but the lack of background compression pushes everything so far away and the photo ends up consisting of more sky and floor than I'd be happy with. So I made a few experiments using the panorama technique. Essentially it's shooting the scene with a tele lens on a tripod, shifting the camera from shot to shot so that each photo overlaps with what's already been shot by about a third. Then I've been using Photoshop Photomerge to put these shots together. And it works perfectly! Okay, my 7-years old Mac Pro was working for half an hour stitching these together, but I end up with a 130 MP image, that isn't distorted, has beautiful background compression and that benefits from the sharpness of the 120mm F/4 macro lens I was using. I'm now editing a fashion shoot using this technique, but before I want to share with you the result of my test session

Ryan Brenizer who is well know for using this technique with large aperture lenses has said "By stitching together these image, you don't increase the angle of the lens, but the size of the sensor". Which honestly makes it even more of an interesting technique to use. Imagine a 130 MP large format camera with your favorite lens' optical properties. How could anyone not get excited about this .

Have fun everyone trying this out yourself



Pentax 645z w/ Pentax smc 645 FA 120mm F/4 macro @ F/11 1s ISO100 -1EV
(the -1EV is crucial in retaining all the highlight detail in the background!)
Converted and edited in Photoshop CC

---------- Post added 10-31-15 at 01:02 PM ----------

Here is a 100% crop on the trees in the background. Check out the hand print on the tree trunk. So much detail....!


10-31-2015, 05:08 AM   #2
Site Supporter
Cynog Ap Brychan's Avatar

Join Date: Sep 2012
Location: Gloucester
Photos: Gallery
Posts: 1,091
Truly stunning photo!
10-31-2015, 08:11 AM - 1 Like   #3
Pentaxian
mcgregni's Avatar

Join Date: Sep 2012
Location: Surrey, England
Posts: 1,629
Nice work! No distortions, that's for sure . Lovely autumnal tones and depth to the scene.
10-31-2015, 09:06 AM - 1 Like   #4
Pentaxian
LensBeginner's Avatar

Join Date: Sep 2014
Photos: Albums
Posts: 2,544
It's not a "wideangle distortion", more of a "close distance perspective"...
However you used that Brenizer-inspired technique to great effect! :-)

10-31-2015, 09:57 AM   #5
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 10,621
Does the 645 have sensor shift composition adjustment? That could speed things up

Also, I guess you are more bothered by the perspective distortion (space compression due to field of view and working distance), rather than the actual lens distortion (pincushion, barrel, mustache). So stitching is a good idea. Otherwise, you can use lens profiles to combat the lens' distortion
10-31-2015, 01:17 PM   #6
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 340
The reason your image lacks perspective distortion is simply that it's not very wide even after stitching, it looks less wide than my 55mm, which itself can hardly be called wide. It shouldn't start to get apparent until after 45mm (35mm FF equivalent).

That said, the stitch method you mentioned is an interesting idea for use on medium format, since it was originally meant for smaller formats to simulate larger ones (barring the differences in optical formulas and dynamic range). I'll wait till I get a beefier computer before attempting this though, my current one struggles with 2-3 shot stitches from the Z, never mind the 8+ required for optimal results.

On a personal note, I refuse to call it the Brenizer method, because it was known and used before he popularized it.
10-31-2015, 01:20 PM   #7
New Member




Join Date: Sep 2014
Location: Zurich
Posts: 19
Original Poster
Computer speed indeed an issue

Yeah computer speed (and memory!) is indeed an issue. As it stands, my 7-years old Mac Pro with 12 GB RAM can process a stitch with about 22 shots. With more images, Photoshop crashes ("out of memory"). Waiting for a new iMac now with 32 GB RAM - an upgrade was overdue anyhow.
10-31-2015, 01:23 PM   #8
Senior Member




Join Date: Jul 2012
Photos: Gallery
Posts: 177
The exaggerated DoF on a wide angle lens means it is more difficult to obtain sharpness over the entire image. The stitching technique has the potential for sharper images.

10-31-2015, 01:24 PM - 1 Like   #9
New Member




Join Date: Sep 2014
Location: Zurich
Posts: 19
Original Poster
QuoteOriginally posted by Kolor-Pikker Quote
The reason your image lacks perspective distortion is simply that it's not very wide even after stitching, it looks less wide than my 55mm, which itself can hardly be called wide. It shouldn't start to get apparent until after 45mm (35mm FF equivalent).

That said, the stitch method you mentioned is an interesting idea for use on medium format, since it was originally meant for smaller formats to simulate larger ones (barring the differences in optical formulas and dynamic range). I'll wait till I get a beefier computer before attempting this though, my current one struggles with 2-3 shot stitches from the Z, never mind the 8+ required for optimal results.

On a personal note, I refuse to call it the Brenizer method, because it was known and used before he popularized it.

You might be right, there. Let's see, I used a 120mm, expanded probably about three times vertically and twice horizontally. Not sure if my math is correct here (note: it almost certainly isn't), but I'd estimate that to lead to a 40-60mm. Which is certainly not an extreme wideangle by a long shot.

Ryan, does say that as well. But at least, we all know what technique exactly it is we are talking about . "Panorama stitching" is misleading too in many ways...

---------- Post added 10-31-15 at 09:31 PM ----------

QuoteOriginally posted by Na Horuk Quote
Does the 645 have sensor shift composition adjustment? That could speed things up
Turn any Pentax lens into a shift lens: Composition Adjustment - YouTube

Also, I guess you are more bothered by the perspective distortion (space compression due to field of view and working distance), rather than the actual lens distortion (pincushion, barrel, mustache). So stitching is a good idea. Otherwise, you can use lens profiles to combat the lens' distortion

It's not a feature of the 645z I'm afraid. In any case this would limit the size of my stitch to how far the sensor can move (or with TS lenses, how far it can shift). By tilting the head it's true I get leaning lines, but the Photomerge algorithm does a great job in correcting these. So it's not really a concern.

---------- Post added 10-31-15 at 09:47 PM ----------

Another note on the 645z. At first I was bothered that the in-camera previews appear much brighter than the RAW files when I open them. But now I think, that's actually a good thing. By slightly underexposing, I retain so much color detail in the highlights while at the same time, there is still so much detail in the blacks that I don't really have to worry too much about it.

Last edited by obsoquasi; 10-31-2015 at 01:47 PM.
10-31-2015, 06:41 PM   #10
Senior Member




Join Date: Mar 2015
Posts: 160
I often stitch 6-12 645Z images taken with the 28-45 (image number of course depends on FL used) without ill effect to my eye.
11-01-2015, 01:35 AM   #11
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 340
QuoteQuote:
Another note on the 645z. At first I was bothered that the in-camera previews appear much brighter than the RAW files when I open them. But now I think, that's actually a good thing. By slightly underexposing, I retain so much color detail in the highlights while at the same time, there is still so much detail in the blacks that I don't really have to worry too much about it.
Check if you have any of the D-range settings turned up, like shadow recovery. Any in-camera adjustments apply only to JPEGs, which the preview image is based off of.

But I intentionally have mine turned up to max, so that the preview image would be more representative of the RAW, since I always expose for the highlights, the shadows would always appear too dark otherwise.
11-01-2015, 04:51 AM   #12
Site Supporter
sculptormic's Avatar

Join Date: Dec 2012
Location: Amsterdam
Posts: 223
QuoteOriginally posted by Kolor-Pikker Quote
Check if you have any of the D-range settings turned up, like shadow recovery. Any in-camera adjustments apply only to JPEGs, which the preview image is based off of.

But I intentionally have mine turned up to max, so that the preview image would be more representative of the RAW, since I always expose for the highlights, the shadows would always appear too dark otherwise.
What is in your view the best settings to expose for the highlights with the Pentax Z?
11-01-2015, 06:35 AM   #13
Pentaxian
Sagitta's Avatar

Join Date: Feb 2011
Location: Maine
Photos: Gallery
Posts: 2,923
IMHO if you're shooting an UWA lens and finding an excess of dead space in the shot, you're using the wrong lens for the photo to begin with. Its like trying to use a 200mm for a landscape shot and finding its too tight - you'd just bust out an 85 or a 50 or whatever it takes to get the framing right and go from there.

If you find yourself stitching a slew of wide angle shots togethether to simulate a 50mm, just use the 50mm! Comp;aining about the lens doing what its designed to do is kind of silly.

That said, I like the shot. The Brenizer method is nice when done right.
11-01-2015, 07:16 AM   #14
New Member




Join Date: Sep 2014
Location: Zurich
Posts: 19
Original Poster
QuoteOriginally posted by Sagitta Quote
IMHO if you're shooting an UWA lens and finding an excess of dead space in the shot, you're using the wrong lens for the photo to begin with. Its like trying to use a 200mm for a landscape shot and finding its too tight - you'd just bust out an 85 or a 50 or whatever it takes to get the framing right and go from there.

If you find yourself stitching a slew of wide angle shots togethether to simulate a 50mm, just use the 50mm! Comp;aining about the lens doing what its designed to do is kind of silly.

That said, I like the shot. The Brenizer method is nice when done right.
It's the other way around, you'd stitch some 50mm shots into a wide angle shot for example.

Like I quoted above, the goal of stitching is not to, say, replace a 50mm shot with some stitched 90mm shots. In fact that's not even possible, because with stitching, the sensor size increases as well. The wider the stitch, the wider the sensor. So the thing I'm personally most excited about this is the possible background compression, that comes along with the technique. Also, instead of buying 12 Pentax lenses (I can actually make due with just a handfull of excellent normal to tele lenses, 55, 75, 120, 200mm. And I'll be able to cover the spots inbetween using stitching. Provided the scene is without motion. If there is motion, I'd have to try and capture the motion in one frame, and expand from that one frame outwards into parts of the image that have no motion. That would probably work best.
11-01-2015, 07:49 AM   #15
Loyal Site Supporter
baro-nite's Avatar

Join Date: Aug 2011
Location: North Carolina, USA
Photos: Gallery | Albums
Posts: 4,298
QuoteOriginally posted by obsoquasi Quote
The wider the stitch, the wider the sensor. So the thing I'm personally most excited about this is the possible background compression, that comes along with the technique.
And the wider the angle of view. You lose the background compression (perspective) of the longer lens; stitching effectively creates a new, wider-angle, optic. I'm a fan of stitching, too. As you point out, it allows you to use one camera and lens and effectively create a larger sensor with the same focal length. "Brenizer technique" (or bokeh panorama, I suppose there are still other terms) allows you to create sensor/optical combinations that are impossible otherwise. And normal stitching allows huge files on the cheap (relatively speaking; a 645Z ain't cheap yet). But perspective is perspective, and depends entirely on where you place the camera.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
120mm, 645d, 645z, adjustment, background, brenizer, camera, composition, distortion, f/4, large format look, lens, macro, medium format, nature, note, panorama stitching, perspective distortion, photoshop, shift, shot, stitch, technique, wideangle
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Best m42 wideangle lens choice? disconnekt Pentax Film SLR Discussion 8 12-22-2014 04:18 PM
newbie wideangle omegatricky Troubleshooting and Beginner Help 7 07-28-2011 09:12 AM
An affordable wideangle lens? systemA Pentax SLR Lens Discussion 6 08-18-2009 05:47 PM



All times are GMT -7. The time now is 05:28 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top