I made a 4" digital back, and you can too

[TomR]

The idea is pretty simple; take a digital sensor and move it in a grid where the film would be. I've just got the bits together and it works, but needs refinement.

I took a 4x5 monorail camera, removed the rear standard, back and bellows. In there place I mounted a '4 way macro rail' with a DSLR on it. The key here is the rail is meant to go horizontal, but I added a couple of 90 degree brackets so it could mount vertical. Now I just have to turn the knobs a bit between each photo to move the camera in a grid to cover the film plane.

I'm not great with words so have some photos.

Here is the camera as it stands right now. It needs some work:


2013-676 by Tom Rintjema, on Flickr

My first test was with a magnifying glass as a lens:

2013-673 by Tom Rintjema, on Flickr

Here is with a real lens:

2013-674 by Tom Rintjema, on Flickr


2013-675 by Tom Rintjema, on Flickr

Please excuse the poor photos. I literally got the thing together and went outside to take photos before it got dark.

Some key points:
I used a cheap 4 way macro rail from Amazon. I think it was $40. It's not very good and a better one would help a lot.
A DSLR has a mirror box that's too deep and causes mechanical vignetting. A mirrorless camera would be better, as there is no mirror box and also it would be much lighter.

That's about it for now.

[TomR]

This photo shows how it works best:


2013-678 by Tom Rintjema, on Flickr

The front standard is normal. I had to use a shirt as a bellows as the one that came with the camera didn't work for what I was doing. All of the movements work still. The rear standard has been replaced by a set of rails to move the camera that is acting like a back around in a plane. It has no movements, but I plan to add them back in when I make a sturdier system. Right now I'm looking for a set of focus rails that have less slack when held on their side.

[Nathan Potter]

OK, this is frequently tried by others with some degree of success. My own opinion is that it is somewhat pointless in that you end up without some of the key advantages of LF or the DSLR when used separately.

In your last photo of the setup I can't figure out what the gizmo is behind the DSLR.

Nate Potter, Austin TX.

[welly]

OK, this is frequently tried by others with some degree of success. My own opinion is that it is somewhat pointless in that you end up without some of the key advantages of LF or the DSLR when used separately.

In your last photo of the setup I can't figure out what the gizmo is behind the DSLR.

Nate Potter, Austin TX.

That looks like the four way macro rail to me.

[Light Guru]

Why not just use one of these DSLR to 4x5 adapters.
http://www.amazon.com/Fotodiox-10-LA...s=Fotodiox+4x5

Not only can you cane the one image like yours is limited to but you can slide the camera on the adapter and take multiple images and then stitch them together.

[welly]

Why not just use one of these DSLR to 4x5 adapters.
http://www.amazon.com/Fotodiox-10-LA...s=Fotodiox+4x5

Not only can you cane the one image like yours is limited to but you can slide the camera on the adapter and take multiple images and then stitch them together.

I'm curious as to whether anyone uses these adapters with any positive results. I see a lot of links to these things but have yet to read a review.

[SergeiR]

Why not just use one of these DSLR to 4x5 adapters.
http://www.amazon.com/Fotodiox-10-LA...s=Fotodiox+4x5

Not only can you cane the one image like yours is limited to but you can slide the camera on the adapter and take multiple images and then stitch them together.

b/c they suck. You not getting full width with those fotodiox ones.. And they do not make them to full specs. At least not one with mamiya..
After some hacking i could get 6x9 images out of it.. but thats about it. And its a bit.. weird. You getting somewhat stereoscopic effects b/c you move receiver, so your nodal points and stuff are shifting..


Cheater by Sergei Rodionov, on Flickr


K-Group got more cool ones, but they are WAY more expensive.

[photonsoup]

I took a cambo lensboard and epoxied the mount from an old Nikon lens to it. On the Cambo, the lensboard mounts on the rear standard the same as the back does. I could rise, fall, and shift to cover the entire 4x5 area and stitch them together, but I don't want to spend that much time on the computer!
I have used it for some macro experiments.

Tulip bud about to open

Cambo Legend, Schnieder Symmar 150mm, Nikon D300

But mainly I use it to compare shutter speeds by checking the histograms of a gray wall.
Oh, I did use it to take picts of the solar eclipse cause I could stop down to f64

[Light Guru]

b/c they suck. You not getting full width with those fotodiox ones.. And they do not make them to full specs. At least not one with mamiya..

I didn't say they were a perfect option. But it is far better then the hack in the original post.

[TomR]

I must not have explained what I'm doing here properly. The gizmo behind the DSLR is indeed a 4 way macro rail, as my post states. It has 10cm of travel both left and right and up and down. What I do is move the camera left and right and up and down taking photos in a grid pattern to cover about 4" x 4" (10cm x 10cm) and stitch the photos together on the computer. Photoshop even has an automated feature that does this with little user input. The result is a photo over 100 megapixels that covers almost what a 4" x 5" negative would.

Just to be clear, each of my sample photos isn't one picture taken with a DSLR mounted in a static position cropped out of the middle of a LF lens field of view, it's a series of photos stitched together that covers most of the view 4x5 would. That's the reason why I don't use the fotodiox adapter, they just let you slide the camera back and forth and use a small area.