The power of Photoshop! 10x8 negatives stitched

[Paul Greeves]

This may interest the photographers, like myself, who shoot large format film then scan and output the prints on an inkjet printer.

I have stitched digital files before but never tried stitching scans together. I found a subject that would test the power of Photoshop. The 10x8 camera was set up and I checked the focus on the three different views. My tripod head has degrees marked on the base and I calculated the amount necessary to overlap the images by about a third.

I closed the lens and took the first image. I then loaded the next sheet, moved the head through 20 degrees and took the next shot. I repeated this for the third and last image. The negatives were processed individually for the same time and temperature to ensure a consistent result.

Each negative was scanned on a Epson V750 using the exact same settings. In Photoshop the negative were stitched by going to File - Automate - Photomerge and selecting Perspective from the list of options.

Here are the three images that were scanned.

[Paul Greeves]

Here is the final image. It took over an hour to join the three images together. The final image was over 1.6GB! I printed the final image on my Epson 7800, giving a 24"x85" print. It could have been printed to 4'x13', without interpolation, if I had a printer that large.

Amazingly, Photoshop stitched the images along joining beams but never crossing a diagonal. There was no need to edit any misalignment. What is more amazing is how Photoshop has corrected the perspective without any distortion.

This facility is only available on Photoshop CS3 or CS4. The CS2 version is more basic.



If you would like to view more of my photographs and see a high quality version of the final image, please visit:

http://www.digitaldarkroomuk.com

[Chris Strobel]

Big thumbs up on that one Paul!Next you need to do a multirow panorama with the 810

:D

[Paul Greeves]

I think what this image illustrates is that Photoshop should be able to join any subject. I purposely chose this subject for its complexity and it worked a treat. It is essential that the camera is perfectly level, particularly if you use a wider lens.

[dazedgonebye]

Should be able to make a reasonable sized print from that. :-)

[jb7]

Amazing-
all that information squeezed into an image 173 pixels high

:D

Seriously though, it does look good-
I considered doing the same myself, but using shift on the rear-
so that the pictures were part of the same image circle anyway-

Just haven't found a suitable picture yet...


joseph

[nathanm]

That's an ambitious project! You are one patient man, Paul. 1.6GB :eek:

[Paul Greeves]

With hindsight, I think I could have achieved the same result with a 5x4 camera. The use of a 10x8 would only really be necessary if you wish to have a bill board size photograph!

[willwilson]

Looks good Paul and sounds like a fun project. I am a big fan of lf and film, but I think digital is king when it comes to stitching. Digital also allows you to shoot over and under exposed shots easily in order to achieve ultra high dynamic range.

Have you visited gigapan.org? I rented a gigapan for a job recently and had a blast tinkering with the thing. Definitely not lf, but it has some similar qualities, specifically patience and pre-visualization. It took about 45 minutes to take the shot below (220 images, 1225 megapixels) and 9+ hours for the gigapan software to stitch it. The final image is too large for me to open in photoshop it crashes my computer!

http://share.gigapan.org/viewGigapan.php?id=19978

[Vaughn]

Interesting project! Did you set up the 8x10 so that it rotated on an axis centered on the center of the lens?

Vaughn

[Paul Greeves]

I have seen an image of Barack Obama being sworn in as President in Washington. I'm not sure how it was taken but it is a panoramic image and you can zoom in and pick out every detail, down to some of the faces a mile away in the distance.

[Vaughn]

Will -- neat shot(s!). Just curious...what happened to the top of the power transmission tower just to the right of the bridge?

[Paul Greeves]

Hi Vaughn. I just rotated the camera on the tripod head, so this wouldn't have been around the lens axis. The first image is parallel to the beams. I still can't believe Photoshop sorted out all the perspective.

[Paul Greeves]

I have found the image of Barack Obama I was talking about. It too was taken using Gigapan software with a Canon G10 digital compact!

http://gigapan.org/viewGigapanFullscreen.php?auth=033ef14483ee899496648c2b4b06233c

[willwilson]

Vaughn, That structure to the left of the bridge is actually a really ugly (I think) outdoor sculpture. There is a stitching error on the left tower of the At&t building. I would fix it, but like I said I can't open the image in photoshop on my computer, only in the gigapan stitching program.

Paul, I used a G10 as well. It's a nifty little camera, a little noisy but sharp. The smaller sensors in compact cameras allows for huge dof at relatively small apertures, which makes these types of stitched images even more detailed.

[Paul Greeves]

I think they are a brilliant concept. I do own a Canon G10, so I may be tempted by a Gigapan day out if a friend will share the cost. I wonder how they would look printed out on a massive scale?

[Vaughn]

Thanks Paul. What would be interesting would be at the camera position with a print of your image -- just to see how the PhotoShop perspective corrections deviated from "reality".

Could you have moved the rear and front standards back on your 8x10 to center the rotation on the axis of the lens? It would be an interesting experiment to make two such panoramas -- one with and one without the rotation on the lens axis...though with 4x5 to same working with 8x10 negs!

Panoramas are fun to do -- though I do not stitch...I just contact the 8x10 negs side-by-side. I have also photographed scenes that, instead of rotating the camera, I have moved the camera/pod parallel to the scene.

Vaughn

PS...Thanks Will...the Gigapan definitely makes an interesting document!

[Paul Greeves]

I see what you mean Vaughn. I'll try it soon. The pictures were taken with a Canham field camera and the Lens standard can't move far enough back. I've ordered a Canham metal field which might be more versatile.

[Vaughn]

I have found the image of Barack Obama I was talking about. It too was taken using Gigapan software with a Canon G10 digital compact!


I have seen this image before on this forum (I believe we played a "Spot the LF cameras" game -- including the 8x10 Deardorf)-- it looks like, even though he is clapping, the ex-Pres. Bush would have rather been somewhere else.

Vaughn

PS...Paul, talking with folks who do a lot of panoramas, including multi-rows, they seem to emphize the rotation on the lens' axis (focal point?)...which requires some fancy tripod brackets with telephoto lenses, which have the focal point in front of the lens! (I hope I am right on that!)

[willwilson]

Vaughn, I think you mean the nodal point of a lens. Basically you want to rotate your camera around the "optical center" or nodal point of your lens in order to record the images correctly for stitching. This point exist in different places for different focal lengths and different lenses/lenses designs. This allows you to take a corrected series of images that can then be stitched together more easily and with less distortion.

Here's some good info from RRS: http://reallyrightstuff.com/pano/index.html

I bet you could mount a small 4x5 to this...maybe??? http://reallyrightstuff.com/pano/07.html

As with all things large format, rotating a large format camera around its nodal point is more difficult than a smaller camera. But you could rotate a leveled monorail view camera horizontally around its nodal point fairly easy just by adjusting the standards and having the right size rail. Multi-row panoramics would be difficult to say the least, although I bet someone on this forum is doing it or used to do it...Chris Jordan? It's hard to beat a 5dii for this kind of thing.

[Ed Richards]

I have to admit, the times I think about moving from 4x5 to 8x10 all hinge around not having to worry about resolution anymore. Do you really need to stitch 8x10s to get what you need? Is the perspective that keeps you from either moving back or using a wider lens?

[Joseph O'Neil]

I have to admit, the times I think about moving from 4x5 to 8x10 all hinge around not having to worry about resolution anymore. Do you really need to stitch 8x10s to get what you need? Is the perspective that keeps you from either moving back or using a wider lens?


Just moved into 8x10 from 4x5 myself (still keep my 4x5 gear to be sure), and it's hard to explain, but all the pre-concieved notions one has about 8x10 seem to fly out the window the moment you first use an 8x10. Like a whole new world. For what it is worth, I think the jump is a good way to go. I will still shoot a lot of 4x5 to be sure, but 8x10 - love it.

As for stitching negatives together, one thing that really pushed me the 8x10 way was a workshop I attended in Toronto, and I saw large contact prints made from "digital negatives".

Bascially you scan in an 8x10 negative, then on clear film - the same stuff they used to use for overhead transparencies - you get printed out on a large printer, a negative that is 20x24 inches (or whatever you want), then do a contact print.

The workshop I was at was platinum/palladium, but I always wanted to do van dyke, and essentially the process is the same.

I have a long, long, ways to go, because getting the tonality right on your digital negatives is an artform in itself, (and I need a whole more more computer tan I have right now), but seeing this thread, and seeing what you can do stitching 8x10 negatives together - imagine for sake of arguement stitching together 2, 3 or even 4 - 8x10 negatives, then printing out one, large panoramic digital negative, and doing a large, a really large contact print. Something so large you have to use a mop and bucket to spread the van dyke solution around on your paper. :D

I know, I'm either smokin' some seriously bad gangi, or I just haven't had enough coffee yet this morning, but wow, it gets you thinking, doesn't it?
:)

[Vaughn]

Thanks, Will...I felt that there was something wrong with my terminology and my "axis of the lens". Nodal point is what I should have been thinking. Vaughn

[nathanm]

My goal was to move up to an 8x10 someday just so I could enjoy the full image circle of my lenses; but here Paul already has one and he wants more more more! Heh! :p The grass always seems greener I guess! I will sometimes shoot two 4x5 exposures with rear shift and stitch them together, but it still strikes me as being too much 'busy work'. Cobbling together multiple shots is sort of cool in a way, but ultimately it's just not as sweet as a single moment in time on one sheet.

[Pete Watkins]

Paul,
Did you use any movements?
Best wishes,
Pete.

[Paul Greeves]

Hi Pete,

The only movement used was about 20 mm of rise on the front standard.

If I try this again, I think i'll be a little more ambitious and maybe try it on 5x4 with a 90 mm lens. I'll put the back into portrait aspect and shoot 6 sheets with something like 120 degree angle of view. I can then process all 6 sheets together in my Combi Plan tank.

[Paul Greeves]

You will have problems with continuous tone areas in CS4 too. The combined images will open in Photoshop as individual layers, so if one is too light or dark you can vary the brightness to some extend or use Quick Mask to select localized areas to vary the density.
If the negatives or digital files were shot on Manual and the images shot in rapid succession, then there should be no problems with areas of the image appearing patchy. If you are shooting large format negative then be sure that the lens more than covers the format so that even slight vignetting is avoided.