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M8 Panos --Nodal point for M lenses

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Well, I followed your advice. Last weekend in Paris, no tripod, but a newly acquired second hand 50 lux ASP. About 9 vertical shots on the Place des Voges. Stiched inCS3

 

One further comment, if I may. In any hand-held pano, it is difficult to get a level image. And the more sub-images, the harder it is. For instance, your Place des Voges appears to be a bit higher on the left than it does on the right.

 

In PS, there are a couple of ways of dealing with this. I always drag a horizontal line down from the ruler bar (Ctrl-R) immediately after the stitching to where the level horizon in the center of the picture is. That will then tell me if I am out-of-level.

 

Then, you can either rotate the whole image to perfect level in Transform, or you can crop the image (with or without Perspective on), or you can be really adventuresome and use one of the other Transform tools. My personal favourite is Warp. Then, Crop to taste. If there are a few missing areas around the margin after the crop, I either Clone in some neighbouring area or use Warp again and stretch an area to fill the void.

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One further comment, if I may. In any hand-held pano, it is difficult to get a level image. And the more sub-images, the harder it is. For instance, your Place des Voges appears to be a bit higher on the left than it does on the right.

 

In PS, there are a couple of ways of dealing with this. I always drag a horizontal line down from the ruler bar (Ctrl-R) immediately after the stitching to where the level horizon in the center of the picture is. That will then tell me if I am out-of-level.

 

Then, you can either rotate the whole image to perfect level in Transform, or you can crop the image (with or without Perspective on), or you can be really adventuresome and use one of the other Transform tools. My personal favourite is Warp. Then, Crop to taste. If there are a few missing areas around the margin after the crop, I either Clone in some neighbouring area or use Warp again and stretch an area to fill the void.

 

The Place des Voges was a "quick and dity" job last night and you are right about it being higher on the left side. I'll try out some of the tools you mentioned.

 

Georg

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Chris, I am not sure which version of PS you are using but all of what you discuss in your post is automatically handled in CS4 and quite effectively in my early experience.....

 

Philip - Old, old, old I'm sorry to say and I'm in no position to change that.

 

I was actually answering Bob, who [below] answered Sander :

 

When horizons are involved, and your pictures are not perfectly horizontal, the software may not be able to render a straight horizon.

The waivy thing that is the result is impossible to correct. CS3, PtGui, Auto Pano: to no avail...... I get round it by opening each individual frame in Photoshop and use the lens distortion tools to rotate each image until it's horizon is horizontal. I then stitch together the straightened frames.

 

I thought that the Measure Tool was a better option to the above, but your reports of improved rotation and matching in CS4 is very interesting. Please be sure to post your imaging results if you can.

 

.............. Chris

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The Place des Voges was a "quick and dity" job last night and you are right about it being higher on the left side. I'll try out some of the tools you mentioned.

 

Georg

Well, Georg, it may have been 'quick' but it is not real 'dirty.' I sense you are beginning to grasp how easy combining images can be even without classic hardware. I think it is a good idea to experiment as you are doing and getting comfortable with the technique step by step.

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Hand held stitching is a great technique - it gives the possibility of large, richly detailed files of MF quality with very light and portable gear. I've found that modest (ie not too wide) lenses work best. The stitching software has less to do (and thus works more reliably) if the lens is free of barrel or pincushon distortion. Work with manual exposures - if exposures change from frame to frame to frame it's very hard to get a good stitch. I start by exposing the brightest and then the darkest areas, reading the histograms to get an idea of the best average exposure that doesn't blow highlights. I take the series of exposures rapidly, overlapping 50% or so (ie pick out an object on the edge of the frame and move the center spot to it). Too many exposures is better than too few, and silicon is cheap. With practice you can plan frame lines so moving people etc. work out ok.

 

I don't use a tripod in urban settings - there is an ever greater tendency for police, docents and proprietors to hassle you if you work on a tripod, either because they think you're a terrorist, they think you should buy something before you shoot, or they are trying to protect the intellectual property associated with the images (this is the case, for example, for the most picturesque areas of Sidney, most church interiors, most museums, etc.).

 

From a workflow standpoint I shoot raw, develop in LR using the same setting for all images, export 16 bit tiffs and stitch them with Autopano Pro - or if that doesn't give optimum results, PTGui Pro. Touch up in Photoshop, copy back to the original directory and import back into LR.

 

Here's a sample from last week in Prague - 5 images (35mm pre-asp Summicron v. 4) stitched with Autopano:

 

 

Perspective could use a slight touch up in PS - the verticals diverge slightly. The stitch is perfect - there are no artifacts of stitching at all.

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Perspective could use a slight touch up in PS - the verticals diverge slightly. The stitch is perfect - there are no artifacts of stitching at all.

 

Pretty nice and it is clear and rectilinear.

 

Since you are using Autopano, you might try the tools within it that level the horizon and also allow you to align the sides of the buildings to vertical.

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Pretty nice and it is clear and rectilinear.

 

Since you are using Autopano, you might try the tools within it that level the horizon and also allow you to align the sides of the buildings to vertical.

 

I use those tools but it's hard to nail it precisely because a very small change in the centerpoint can have a dramatic effect on perspective. I get as close as I can and then make a final adjustment in PS.

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Woody - As someone who has done a lot of view-camera architectural work I think your image is far far better than any 'simple' technique deserves - well done. I downloaded the image to check the horizontals and verticals and your image may well be truthful to the original building but looking not-quite-right because of the optical illusion thrown out by the sloping road and construction inconsistencies. I'm impressed, but what really pisses me off is how much hard work I used to put into view-camera work to make images that were distinguished, and now hand-holding can have it's equivalence. It doesn't seem fair somehow.

 

Thanks for posting.

 

................ Chris

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Hand held stitching is a great technique ...

 

I don't use a tripod in urban settings - there is an ever greater tendency for police, docents and proprietors to hassle you if you work on a tripod, either because they think you're a terrorist, they think you should buy something before you shoot, or they are trying to protect the intellectual property associated with the images (this is the case, for example, for the most picturesque areas of Sidney, most church interiors, most museums, etc.).

 

....

 

Here's a sample from last week in Prague - 5 images (35mm pre-asp Summicron v. 4) stitched with Autopano:

 

 

Excellent work, Woody. It is very difficult to see how a tripod, with even the world's most expensive pano head, would have improved this image. However, in a low light situation I can certainly see that a tripod and pano head would be useful.

 

Choice of post-production software is more debatable. Your concerns about balancing the exposure may (just "may") be obviated by the new improvements in Photoshop CS4.

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Philip - Thanks, I enjoyed that. It's fairly inevitable that people will want you to include an image here, so I'll try and coax you with a question. The files I checked were 35mm shots; without rising-front that's not a wide lens, even in portrait mode, for cathedral sized building heights. I have presumed that you and Woody were rotating the camera as vertically as possible, stitching, and then cropping excess off the bottom of the image. Is that correct, or have you been shooting two rows, and thus introducing divergence of verticals? I find it hard to believe that software could handle the latter [without a 'nodal rig'], but I am a little puzzled.

 

.................. Chris

 

PS - In case you don't know - cathedral columns were constructed to lean outwards, they aren't vertical, though when photographed accurately the images then tend to look poorly corrected. The intuitive and experiential knowledge of medieval builders was phenomenal. I don't know Winchester, but if you come to the UK again Wells Cathedral [in Somerset] is intoxicating, it's where Frederick Evans made his photographic masterpiece The Sea of Steps.

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Philip - Thanks, I enjoyed that. It's fairly inevitable that people will want you to include an image here, so I'll try and coax you with a question. The files I checked were 35mm shots; without rising-front that's not a wide lens, even in portrait mode, for cathedral sized building heights. I have presumed that you and Woody were rotating the camera as vertically as possible, stitching, and then cropping excess off the bottom of the image. Is that correct, or have you been shooting two rows, and thus introducing divergence of verticals? I find it hard to believe that software could handle the latter [without a 'nodal rig'], but I am a little puzzled.

 

.................. Chris

 

...

 

This screen shot from PS should give you an idea of what is going on:

 

 

The larger image is how PS CS4 showed the image after it ran through its automated stitching and blending. On the right, you should be able to see the twelve layers (with their individual layer masks) stacked vertically. The thumbnail on the left is the captured image from the camera positioned on the virtual canvas (the checkerboard background) where PS has figured it should be. Times 12. The thumbnail on the right is the mask that PS has calculated that covers each respective frame capture to its left to have the best characteristics for the composite image. So, it uses varying amounts of each image for the final composite. All automatically. You may notice that PS masked out almost all of image 0033, presumably judging that there was better content in adjoining images. I could have overridden that by going in an manually changing the mask of that image or any of the adjoining images.

 

I have taken basically two tiers of images with the M8. I swept along the lower lever left to right then I aimed the camera higher (roughly allowing some overlap) and then swept right to left. Finally, I was not sure I had enough of the top so I took an additional shot of the top of the cathedral with plenty of sky above it. Actually, I made a mistake of not starting far enough to the left for the first image (which would have been mostly wall) and I had to clone some wall onto there for the final image.

 

To eliminate most of the fish-eye effect, I used Edit->Transform->Warp to straighten the horizontal lines, cloned some wall as I said before, cloned out the jet contrail sticking out of the roof, warmed up the color balance, and cropped.

 

Actually, I think this would have been harder to do with a pano rig for the off-level shooting.

 

I hope this answers some of your questions.

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OK, here some are: Winchester Cathedral - a set on Flickr.

 

These are all hand-held multi-image compos; I am finding it harder and harder to shot just a single frame. And then when I do, I don't like them as much.

 

Ain't it fun! I! And I recognize the feeling. I had some 40 of my pano's printed at 80 cm wide with Pixopolis - Fotoentwicklung Fotobuch Digitalfoto Fotolabor Kalender Poster Leinwand , the book came in yesterday and it is a stunner.

 

Sorry Philip: the link in your last post does not work. Try to uses Manage Attachments when you make a new post. Do not forget to close the box when done.

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Ain't it fun! I! And I recognize the feeling. I had some 40 of my pano's printed at 80 cm wide with Pixopolis - Fotoentwicklung Fotobuch Digitalfoto Fotolabor Kalender Poster Leinwand , the book came in yesterday and it is a stunner.

 

Sorry Philip: the link in your last post does not work. Try to uses Manage Attachments when you make a new post. Do not forget to close the box when done.

 

Thanks, Sander, that's exactly what I forgot to do.

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Ain't it fun! I! And I recognize the feeling. I had some 40 of my pano's printed at 80 cm wide with Pixopolis - Fotoentwicklung Fotobuch Digitalfoto Fotolabor Kalender Poster Leinwand , the book came in yesterday and it is a stunner.

 

....

 

Sander, I was hoping to see your panos but the link of your post only goes through to the pixopolis index. I think it may be because I am not a registered user whereas you are.

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Sander, I was hoping to see your panos but the link of your post only goes through to the pixopolis index. I think it may be because I am not a registered user whereas you are.

 

Philip,

 

The Pixopolis service does not let you look at book like Blurb does. I just included the link to show where they are. Unfortunately their site is not in English.

 

Some of my last pano's can be found on Sander van Hulsenbeek Blog

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Philip,

 

The Pixopolis service does not let you look at book like Blurb does. I just included the link to show where they are. Unfortunately their site is not in English.

 

Some of my last pano's can be found on Sander van Hulsenbeek Blog

 

OK, thanks for explanation re Pixopolis.

 

Nice blog, nice panos on your link. I assume all M8; what stitching software are you using?

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........... I assume all M8; what stitching software are you using?

 

Yes, all M8. I use PTGui, which serves me OK and is pretty fast in its most recent incarnation.

 

I am sure Autopano and CS4 are great too and merit their faithful following, but I am not sure their advantages over PTGui are worth the 99 EUR/300EUR cost/update respectively.

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...... hope this answers some of your questions.

 

Philip - Many thanks for taking the time to explain. I am looking forward to seeing the screen shot. My logic tells me your results shouldn't be possible, I actually find the improved stitching software amazing. If you can give a 'Valid Attachment' screen shot, that would be great.

 

.............. Chris

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