Enlarging lens used for flat art copy

[greg lockrey]

This may sound like a dumb question but could an enlarging lens be

fitted to a 4x5 camera and used to copy flat art? The fact that it

doesn't have a shutter is not an issue since I plan to use a full

frame digital 35mm camera as a back. The thought is the field will

be flat.

[glenn_thoreson]

The lens will work fine but I'm unfamiliar with the digital setup. For maximun flat field performance, the image should pass through the lens the same way it would on the enlarger. In other words, it would be reverse mounted on a camera.

[kelly_flanigan1]

This has been done for over a decade as a way to scan artwork. Some of us use a 4x5 digital scan back, a 4x5 camera, and an enlargeing lens that is NOT reversed. The artwork is larger than the scan back, thus the typical filter ring/aperture part of the lens faces the larger image, ie the artwork. Here I use a 135mm F5.6 Schneider Componon with a Phase One 35MP scan back on a 4x5 camera. With a small 35mm digital camera; you might just try a standard 50mm lens that is slower; ie an F2 say. These have usually less barrel distortion than most F1.4 lenses. An enlarging lens will work well too, you just need to gin up some tubes. An enlarging lens used say at F8 will make a nice copy lens for artwork. With a 4x5 camera as a camera you will need a longer lens say a 75mm or 100mm enlarging lens, depending on how close you can afit the full frame 35mm back tot eh 4x5's film plane. With my 4x5 speed graphic some of my metal lens boards are already at 39mm diameter, thus the Lord gave us an easy way to mount regular enlarging lenses. The better more complex 5 element Kodak Ektar and 6 element Componons, Rodagons, most El Nikkors work well with closeup work. <BR><BR>With say a 75mm or a 100mm lens on a 35mm digital; the working distances will be abit longer. A thought is just to use a 55mm or 60mm regular "35mm format" macro lens, and avoid the 4x5 camera gambit. The old series 1 90mm Vivitar is great for copy work, plus most all 100mm micro lenses too. <BR><BR>With a t-mount one can jsut use a paper tube to afix an enlarging lens. This is what I did with my old Exakta system.

[kelly_flanigan1]

The lens at the top left corner is a 189mm F4.5 Acromat; afixed to a cardboard tube, using an old Edmund 1 1/4 inch telescope eyepiece tube to T mount adapter, plus an Exakta T-mount adapter. The lenses at the upper right are two 50mm Enlarging lenses on cardboard tubes; that also mount on the 1 1/4 to Tmount rig. I also use this with Nikon stuff too. The tubes are baffled with concentric balsa black matte washers, so contrast is really excellent. This is a typical 1960's solution for macro work. When the image at the sensor or film plane is larger than the object; then you reverse the enlarging lens for better performance.<BR><BR><img src="http://i4.photobucket.com/albums/y148/ektar/Images%20of%20cameras/tripods-191.jpg">

[vivek iyer]

"This may sound like a dumb question.."

 

It is when considering the proposed use of a 4x5 camera and a 35mm DSLR together to make photos of flat art.

 

Why would you need a 4x5 camera for that?

 

Any of Canon's macro lenses mounted on the DSLR should do just fine.

[greg lockrey]

Some of the art work that I scan are large murals greater than 4x8 feet. Most of the time I do not have the room to copy the art with one take. The intent is to digitally photograph segments of the image as "square" as possible and stich these images together in Photoshop. I'm just a poor boy from Michigan and using a DLSR on my 4x5 is just a cheaper way to scan. BTW, thanks to everyone who responded...I was thinking that using an enlarging lens would work rather than investing in a process lens..

[greg lockrey]

BTW, rather than purchase new lenses etc. I rather use the equipement I already have and just add the DLSR. I already have Leitz and Schneider lenses at my disposal and a couple of 4x5 cameras. I don't really want to invest in anymore lenses at this time when I already have some of the best. I found a source where I can attach a Canon 5D on my Sinar and shoot away.

[michael_briggs2]

Gregory, now that you have further described your application, I suggest that the criteria to consider, in order, are: reproduction ratio, low distortion and flat field.

 

You don't say into how many segments you will divide the murals, but the size of 4 by 8 feet versus the sensor size of 24 x 36 mm suggests that the reproduction ratio will be high, perhaps 1:20 to 1:40. This is outside the design range of most enlarging lenses. If you divide the mural into many segments you could get closer to the typical intended reproduction ratio of enlarging lenses. Most manufacturers list intended reproduction ratios on their datasheets.

 

With these high reproduction ratios, you might do better using a high quality normal taking lens. The reproduction ratio is not really closeup and more of a normal scene.

 

If you do use an enlarging lens, definitely not reversed: have the biggest object, the art work, on the side where the printing paper would be in an enlarger. Enlarging lenses are almost always asymmetrical and you want to maintain the intended reproduction ratio orientation.

 

Since you will be stitching the segments together, a lens with low distortion will help. Many datasheets list the distortion, so you can check this figure on the lenses that you already have. Typically symmetrical or quasi-symmetrical lenses do well.

 

I don't think that flat field is the should be the leading criterion. After you exclude extra-fast lenses, and after you stop the lens down a couple of stops, I think any modern LF lens will satisfy this criterion.

[kelly_flanigan1]

One friend that does this type of work ON SITE uses a dlsr, and just a 50mm or say 35mm Focal length lens. He measures the distortion of each lens at the reproduction ratio for critical work, then <b>backs out</b> the distortion at the "combining the panel stage". Folks who do panoramic images digitally have done this for many years.<BR><BR>If you really going to use a dslr; then using just a standard slower lens for 35mm might be tried. An LF lens would be alot longer, and require the camera to be alot farther away, maybe thru a wall! A huge problem is getting the lighting even, camera square to the artwork, if you move the camera. This effect may totally swamp any distortion concerns.<BR><BR>Enlarging lenses made for large reproduction ratios are/were used in the Mural and Microfilm blowback industries. The old 60mm Schneider Componon-M I have for our old Durst 138S's microfilm blowback was a variant made for making large prints. Enlarging lenses like this are not as common, and vary widely in pricing. <BR><BR>What type of dslr do you have; or going to buy? There are alot of nice macro lenses that might be tried, reasonable in cost, with no added hassles of ginning up an adapter. <BR><BR>If the resolution is still ok, and ther is enough space, I prefer a longer lens when shooting artwork. There is less illumination falloff, since the lens is being used over a narrower angle.

[greg lockrey]

Michael, thanks for your input- I am told that it is possible to sticth together up to 9 images using a Canon 5D to make one large scan. 9 x 12 = 108 mb for example. Not just one 24x36 capture at 12 mb. Instead of just using a 4x5 negative having it processed and then make a scan, the idea is to have a digital capture from the get go and have a 4x5 neg as a back up. Presently I do most of my scanning on an Epson 10000XL and stitch those images together in photoshop. I had a machinist friend of mine help me make a table where I have the scanner installed with a movable bench that is perfectly parrallel in order to be able to "index" large pieces squarely so that they can be stitched automatically in PS. This works very well for images up to about 30x40" or so. I have a client who does murals and likes making limited editions of his work as well. Scanning 4x5 negs works very well, but I can theorectically do it quicker and with less cost digitally.

[kelly_flanigan1]

When Our shop had a local 4x5 lab we shot 4x5's of artwork, then either flatbed scanned or farmmed them out for a drum scan. The turnaround time grew worse, our local lab got senile, lost our negatives and tranys too many times, then they died. <BR><BR>We dabbled in 35mm shots 1 hour processing and inhouse scanning at 4000dpi for small pieces of artwork, and did the stiching gig with 4, 6 or 9 panels too. In the end it was easier to just do one direct scan with a 35MP 4x5 scan back, and avoid the processing and stiching. It was a mighty leap in throughput and a huge/big capital expense. This was when a high end 35mm dlsr was still real expense too. <BR><BR>In some large cities there are 36" or 54" wide scanners with a color head, were one just inserts the original, even if it is 1/4 inch thick and mounted. The resolution is alot higher than one can get with a photographic method. A 30x42 color image at 400dpi is 577 Megs at 8bit RGB. These have been around for over a decade now<BR><BR>With our Fiery based 11x17 scanner, it scans at 400dpi too. Here one can take the lid off and do 4 scans of each quadrant; and stich them together. This makes a quick 400dpi scan of a say 20 x 30 inch piece of artwork; ie 275megs This scan then is sometimes enlarged in color to say a 36 or 40" width for a larger poster. The Fiery scanner is just a calibrated color copier, there are no lights to fiddle with, the 4 scans can be done in less than 15 minutes total.<BR><BR>Some "artwork" scans appearance/quality are highly dependent on the lighting angle used. Your client might not want a sterile lifeless 2D "look" of their masterpiece. <BR><BR>Another pitfall is the 36" and 54" color scanner chaps are often doing super cheap scans, sometimes just a handfull of bucks.:) <BR><BR>Exact color matching can be a headache, the gamut of some weird artists materials can be wider than a dslr,films,of scan backs response. <BR><BR>You client might be colorblind too; 1/10 of the men are. <BR><bR>Some folks really just want an image of their artwork for a resume, and the resolution requirements are very little. A one shot digital shot with a FF dslr might be overkill for a 30x42 image.<BR><BR>For research and archival work, our shops clients often require metric or inch steel rulers at the edges for scale, a greyscale reference, a color swatch reference, plus a data sheet for cataloging purposes. A budding artist usually doesnt want ANY of this stuff, and considers it clutter. <BR><BR>The term "artwork" can mean anything today. It might be a pre cival war map, a painting, a kids watercolor of Barney, line art done with a technical pen, charcoal nude drawings, inkjet, slides, watercolors of sunsets, or the god zillion rare sunset and cat images folks print today. "Artwork and Fineart" are used so much today to mean anything, the the terms "artwork and fineart" have no real meaning anymore. <BR><BR>If anything today it just means the work is important to the creator. When two artists are at the counter, which ones work is really art? When one leaves, the other one often says "his/her work is not really art" <BR><BR>Once we scanned a cool artwork image made out of jellybeans glued to a giant board, then all the authors/kids signed it. Then they wanted "copies" for just a few bucks each. We had to mess around with the lighting abit, some jobs you do just for the love of it, for kids.

[greg lockrey]

Kelly, Thanks for your imputs also...I know what you mean. High end scans in Toledo, OH go for $100.00 and the best print houses actually have to take them to Bowling Green State University to have the scans made on their Scitex Flatbed. From what I understand, the machine cost them $55,000.00 so I guess they have to recover their investment somehow. My clients used to go there too but have found that my methods satisfy their needs nicely for as little as $.04 per square inch on my flatbed and a location shooting fees for 4x5" and then scanned by me on my flatbed. I have a pretty good location set up employing cross polarized quartz lighting. Since I print these on my Epson 9600, all of my calibrations are set for my printer/paper. It's pretty much nailed down to a science. Once in awhile I find an artist who uses a media that doesn't copy with exact fidelity, but that's pretty much fixed in photoshop.<div></div>