blending images and registration problems

[rickwinkler]

I use the Sinar f2 4x5 for landscape shots in the Rocky Mountains. I use Velvia 100 and scan them in on an EpsonV750 Pro scannner. I so scan both slides in at the same settings including dimensions and file size. I have tried wet and dry mounts, neither have made a difference. I have yet to find a time when both of these images will align perfectly in Photoshop. Anybody have an idea where I'm screwing this up?

Thanks in advance,

Rick

[Alan Davenport]

If you ever figure it out, let me know. I've experienced the same thing. I think the root cause is that consumer-grade scanners (no matter how "good" a grade) are simply not accurate enough to be that repeatable.

[Peter De Smidt]

The "photomerge" command doesn't work?

[rickwinkler]

This is taken an exposure for the highlights and a second exposure for the shadows. I Photoshop you copy the darker print and paste it over the light print. Then use a layer mask to reveal the shadow detail from underneath. Photomerge is used for panoramic shots

[Kirk Gittings]

With the same problem as the OP. I have used "auto align layers". Part of the problem is the cheap step motors in prosumer level scanners which will not, pixel for pixel, give you identical size scans even from the same negative oftentimes. If you have CS3 though you can use auto align the layers.
See http://www.youtube.com/watch?v=ca02T4Enp_c.

[m332720]

You could try opening the same scan twice in Adobe Camera Raw. Process one for the high lights and one for the shadows.. The combine them back together in photoshop.

[neil poulsen]

With the same problem as the OP. I have used "auto align layers". Part of the problem is the cheap step motors in prosumer level scanners which will not, pixel for pixel, give you identical size scans even from the same negative oftentimes. If you have CS3 though you can use auto align the layers.
See http://www.youtube.com/watch?v=ca02T4Enp_c.

Very cool. I compound separate exposures on a regular basis. Believe it or not, I just got CS3 about three weeks ago and didn't realize this feature existed. (I'll get a free CS4 update, when it's released.)

I usually match digital, so I don't worry too much about alignment. But still, there could possibly be a difference frame to frame. So, will give this a try.

Thanks, Kirk!

[rickwinkler]

I as well did not know about this. I used two shots of the Crystal River Mill which I could not get lined up by hand. Using the Auto-Align Layers worked very well!!:)

Thanks again, I now have a lot of work ahead of me thanks to this.

Rick W

[Peter De Smidt]

What Kirk suggests should work fine. Note that you don't need to use masks. Once the layers are aligned, double left click with the pointer in the blank space to right of the layer's name in the layers palette. This will bring up the layers style dialog box. Near the bottom are two gray scales with slides. The top one, labeled "this layer", allows you to let the bottom layer show through. For example, as you move the black slider on the left to the right, you'll let the dark tones from the bottom layer through. As you move the white slider to the left, you let the lighter values from the bottom layer show through. Note, to make the transition smoother, you can alt click on the slider indicator to split it in two, and you can drag each half of it where you'd like. Don't forget to toggle the preview button to see a quick before and after. Usually this work very well, and you can always add a mask to the layer if needed.

[Leonard Evens]

I've had reasonable success using hugin, which is one of the interfaces for Panorama Tools. I work under Linux, and hugin is the only interface available. There are more choices if you work under Windows. Try googling "Panorama Tools" for more information about what is available.

These tools have a steep learning curve, but they do an excellent job when you finally master them.

I include an example below. this was taken by merging two pictures taken from the same position, with the camera turned in one about 15 degrees to the right and the other 15 degrees to the left. So. in addition to merging in the overlap, perspective correction to make the horizontals parallel was necessary. Just merging is less demanding.

I've reduced the resolution for posting. the original was an 88 MB tif image.

I should say that all these tools, including any in Photoshop, are designed on the assumption that the images were produced on smaller formats than 4 x , so the image sizes are, from our perspective, fairly small. If you use them with images from larger format, you should expect some difficulties.
.

[Leonard Evens]

For some reason, the file containing my example didn't get uploaded. I'll try again.