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Thread: 8 frame stitched pano with A7RII and 24TSE

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    8 frame stitched pano with A7RII and 24TSE

    What I discovered while experimenting is that its important to get the camera back vertical to help eliminate parallax distortion.

    I have a panning plate and nodal point slider to get the nodal point over the center of the panning center. The result is four frames with the shift centered and 4 frames with the shift elevated to include the sky. Used 12.5 magnification to focus on the door frame. F8, 100 ISO, manual shutter 1/100. The exposure was to ensure highlight detail. The histogram shows no shadow or highlight clipping.

    The brick driveway is problematic for this kind of stitched pano since the relationship between the camera sensor and the lines changes dramatically. On the right side its quite apparent, on the left not so much. There is also a minor alignment problem with the shrub on the right at the top of the stitch in the bricks that is easily corrected. Since the main interest was to see how much sky and foreground was possible this was successful. In a shooting situation for a client, it will be important to anticipate where stitching problem might occur.

    The resulting file is 12385x11708 pixels. That means a 41x39 inch print at 300 pixels per inch without upresing. And as you can see if you choose to download the full res JPG quite sharp throughout considering distance to camera and depth of focus.




    HERE is the full resolution JPG for download to review. It should download automatically when you click on the link.
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    Senior Member Hulyss Bowman's Avatar
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    Re: 8 frame stitched pano with A7RII and 24TSE

    Nice performance but what I see, is that weather and clouds moved during your long manipulation. A 3 frames portrait stitch with shift would have been sufficient and more clean. Just my two pesos
    Kind regards - Hulyss - hulyssbowman.com

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    Question Re: 8 frame stitched pano with A7RII and 24TSE

    You're right about the clouds moving during the exposures.
    Looking at the full res image I don't see any problems with the stitching in the clouds. They, overall, are about what I would expect. I'll have to go to one of the individual frames, but I don't think they are any more sharp.

    I think Lightroom merge uses similar technique as photoshop. That is to find the part of each frame that it wants to use for the composited pano. The approach doesn't cause any ghosting but does cause the problems that are apparent in the driveway.

    That kind of movement, whether clouds, grass in the wind, tree branches or whatever are part of the decision process. Horizontal with the shift would have meant Probably one less frame in the pan. That really wouldn't have made a significant difference in this situation.

    Finding the least disruptive compromise is one objective with each shot.

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    Re: 8 frame stitched pano with A7RII and 24TSE

    Honestly, if you are serious about stitching for panoramas or higher resolution shots, LR/PS won't do the job. You'll need something like this: https://www.ptgui.com.

    It's not free (but it does have a free tryout) , nor is it very easy to master. However, the results are about as good as you can get.
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    Re: 8 frame stitched pano with A7RII and 24TSE

    Quote Originally Posted by dmward View Post
    What I discovered while experimenting is that its important to get the camera back vertical to help eliminate parallax distortion.

    I have a panning plate and nodal point slider to get the nodal point over the center of the panning center. The result is four frames with the shift centered and 4 frames with the shift elevated to include the sky. Used 12.5 magnification to focus on the door frame. F8, 100 ISO, manual shutter 1/100. The exposure was to ensure highlight detail. The histogram shows no shadow or highlight clipping.

    The brick driveway is problematic for this kind of stitched pano since the relationship between the camera sensor and the lines changes dramatically. On the right side its quite apparent, on the left not so much. There is also a minor alignment problem with the shrub on the right at the top of the stitch in the bricks that is easily corrected. Since the main interest was to see how much sky and foreground was possible this was successful. In a shooting situation for a client, it will be important to anticipate where stitching problem might occur.

    The resulting file is 12385x11708 pixels. That means a 41x39 inch print at 300 pixels per inch without upresing. And as you can see if you choose to download the full res JPG quite sharp throughout considering distance to camera and depth of focus.




    HERE is the full resolution JPG for download to review. It should download automatically when you click on the link.

    I think you must have an issue with your nodal point. I'm fairly sure the 24mm doesn't have a variable focal length at the edges (i.e. not too much distortion). I also agree with the use of PTGUI for doing work like this..
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    Re: 8 frame stitched pano with A7RII and 24TSE

    I did a test to arrive at the nodal point by placing a stick in the ground about 3 yards in front of the camera and aligned the stick and a vertical frame on a sliding glass door that was at least 10 yards behind the stick. The relationship between the stick and the frame did not change when moving the camera to extremes of horizontal image frame. Not sure how to make it more precise. It turned out to be at the same point as the tilt pivot point on the lens which makes some sense.

    The images used for the extreme edges of the image above had the camera rotated nearly 45 degrees from center.

    I do plan to experiment with the software mentioned.

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    Re: 8 frame stitched pano with A7RII and 24TSE

    Quote Originally Posted by dmward View Post
    I did a test to arrive at the nodal point by placing a stick in the ground about 3 yards in front of the camera and aligned the stick and a vertical frame on a sliding glass door that was at least 10 yards behind the stick. The relationship between the stick and the frame did not change when moving the camera to extremes of horizontal image frame. Not sure how to make it more precise. It turned out to be at the same point as the tilt pivot point on the lens which makes some sense.

    The images used for the extreme edges of the image above had the camera rotated nearly 45 degrees from center.

    I do plan to experiment with the software mentioned.
    I have stitched very complex 360 degree panoramics using PTGui with great success with correctly located nodal points. (It actually made a pretty descent attempt in my first panos where the nodal point wasn't located). I don't know what you have used here. Was it Photoshop. In my experience photoshop makes a pigs ear out of more complex rotational panoramics. Bear in mind rotational panoramics do not work as well when you have linear subject matter. They just end up looking distorted and curved. Not a great look IMO. Another plus with PTgui is if you have the computer with enough processing power it can process huge files in seconds. In my case over 35000 x 7200 pixels. With Photoshop on the other hand it is painfully slow. Even with high spec'd computers.

    Cheers
    Enda

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    Re: 8 frame stitched pano with A7RII and 24TSE

    I spent some time today fine tuning the parallax point on several lenses. As pointed out my first attempt resulted in inaccurate measurements.

    The tests that I shot using the same very patterned driveway have turned out as hoped without any misfitting. I plan to post a couple examples here when I finish with them. These tests were accomplished using the merge to Pano feature in Lightroom 6. Its not fast but its handy and creates a DNG file which has its advantages.

    I plan to download the software mentioned. I think its the same software I used several years ago when experimenting with stitching.

    I have no current interest in doing large arch panos so the benefits offered in that area will be lost on me.

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    Re: 8 frame stitched pano with A7RII and 24TSE

    Here is essentially the same view as the first stitched image. This time using a precise parallax (nodal) point for the 24STE.
    I also shot this in horizontal orientation with 10 points upward shift for the top row and 5 points downward shift for the lower row.

    Its immediately apparent that getting the parallax point correct for a lens makes all the difference. This time there is no problem with the brick driveway or the line of shrubs. As before this was stitched using the pano merge feature in Lightroom 6.

    I downloaded PTGUI and am going to do a version with the same images with the demo version to see what improvements it offers.

    This one looks quite good.



    HERE is a link to the full sized version (33meg. Its 12586x7194 pixels.

    HERE is a link to the full sized version PT GUI output. (52meg.) Its larger because its not cropped. This is the default output from the program without any attempt to optimize.

    I watched a couple of the videos and it looks like a very good tool. It is the same program I used almost 8 years ago. At that time it was the interface for stitching software that I had found via a web search. It appears to have been enhanced and is something to explore in more detail.

    I was pleased to see that it could import the A7RII raw file. I anticipated having to either use the camera jpg files or output the raw files as TIFFs.

    In this situation its hard to see the difference between what it created and the output from Lightroom.
    Last edited by dmward; 4th September 2015 at 14:01.

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