Problems scanning a daguerreotype

<p>I'm scanning a small, approx 2"x3" daguerreotype that is encased in its original glass "book." The scanner is a Lexmark X5410 all-in-one, and the software came with the scanner.</p>

<p>I don't need a professional level scan, but I do need it to be focused on the daguerreotype, not the case it's in.</p>

<p><img src="http://i306.photobucket.com/albums/nn279/robertscrivener/daguerrotypee.jpg" alt="" width="608" height="753" /></p>

<p>Is there any way to scan this effectively?</p>

<p>You're running into a depth of field problem. Scanners are cameras, and their lenses have DOF, just like your camera's lens. It's shallow DOF, because their magnification is high and their lenses are relatively fast.</p>

<p>The way to scan it effectively is to get a different scanner, one capable of focusing above the glass. Some scannera with negative scanning ability can shift their focal point to a few mm above the glass. A more radical solution is to lower the glass a few mm on your scanner.</p>

<p>Probably the best solution is to set up a camera and lights and photograph it.</p>

<p>I honestly think you would be better off taking a photograph of it,using soft lighting and/or a polarizer. Additionally, one could remove the plate from behind the glass ,being aware that dags are extremely fragile and try to photograph it then or even scan it then. The dag will still be very shiny however, and still difficult to get a copy in either event. For god's sakes, don't try to clean it in any way. this one has a bit of tarnish which is common with many dags. Restoration is very difficult to accomplish with these and may do mor harm than good. Best to just try photos or scans as above.</p>

<p>Please don't consider Rod's suggestion of removing the dag from behind the glass. It is so delicate, that you can remove the image with a down feather. I've seem many dags ruined by "restorers" who had good intentions.</p>

<p>One special issue when photographing a dag is that the background is polished silver. It was meant to reflect the dark velvet of the inside cover of the case. If you just take a normal photograph of it, you will get the reflection of the camera in the background. The best way to photograph it is to use a view camera or a shift lens. Set the camera up above the dag, but to the side. Shift the lens over so that the image is corrected. You need to set the copy light offset to compensate for the unusual camera position.</p>

<p>Alternatively, you can use a normal lens and tilt the camera to achieve the same result as above and use Photoshop or other pp software to correct the perspective.</p>

<p>The key for either technique is to make sure that the background of the image reflects a dark area to make it look black.</p>

 

<p>The Life Library of Photography volume on Caring for Photographs has detailed discussion of how to deal with daguerreotype images in restoration. The first step is to photograph the image.<br>

Scanners weren't in the picture then, but as noted, the image is actually a negative*. Reflection is going to make it hard to scan.<br>

________<br>

*If you take a very thin negative and back it with black you will get a similar effect.</p>

<p>Another place to try is the Daguerreian Society. They have more information and anything related to Daguerreotypes than probably anywhere else in the world.</p>

<p>A scanner uses coaxial light - fine for documents, not so good for 3-D and reflective objects. Daguerreotype images are best viewed with oblique light - the image you see is actually a reflection of the light source. A treatise on their restoration would explain this in better detail.</p>

<blockquote>

<p>A scanner uses coaxial light - fine for documents, not so good for 3-D and reflective objects.</p>

</blockquote>

<p>There's only two things wrong with that statement.</p>

<ul>

<li>A typical scanner uses one or two lights at 45 degree angles. The ones you confuse with coaxial light are the better ones with two 45 degree sources, one preceding and one following the sensor.</li>

<li>Coaxial light (aka "epi-illumination" in technical fields) is the preferred method of dealing with the most highly reflective subjects. It has been the standard for metalographic photography for decades, as well as coin photography for professional publication. </li>

</ul>

<p>Thanks for the info - John, your reference was really helpful. I didn't even know where to start looking.</p>

<p>I previewed the scan and selected only the inner part of the frame to be recorded, and I got a better focused image; but still not quite right.</p>

<p>Taking a picture of a dag is a lot harder than it looks.</p>

<p>Back in the 70s we in the photography club were tasked with document copying duties (pre-xerox) and often used a copy stand with soft lights on both sides. The result was quite good. I'd be tempted to try that instead of the scanner and maybe even experiment with polarizing the light either with a lens filter or a filter over the lights to see if the "right" reflection could be achieved with the Daguerreotype.</p>

<p>you won't be able to scan it, because as noted above it's basically like shooting into a mirror. a daguerrotype is different from an ambrotype or tintype. it only looks like a positive when the light hits it exactly right, otherwise it can appear as a negative image. when you shoot them--you have to use a view camera or something (post processing) to correct the perspective. the basic setup is to have a black card on one side of the piece, and rake light across from the other side. i've always done it using a 4x5 view camera and used swings to correct--tilting the union case over to one side facing a black card. I think you might be able to do it using a digital camera shooting through a black card ( the card will mask out the camera and it might be big enough to reflect back into the piece--if you can offset it and then crop into it, but this is a big waste of image resolution--tilting it is probably better. here's a real low res scan from a database of something I shot on 4x5 chrome film. it's a toyo view camera aimed straight down on a daguerrotype propped up at an angle towards a black card. front & back swings corrected it. the lens here is a 150mm G-claron, this was probably on fuji provia 100F.<br>

<a href="http://collections.ncdcr.gov/dcr/ShowFullImage.aspx?19XX.319.15~0">http://collections.ncdcr.gov/dcr/ShowFullImage.aspx?19XX.319.15~0</a><br>

hope this helps. my opinions only as always.</p>

<p> </p>

<p>if you have problems with that url--the number for that artifact is 19XX.319.15. search on that. there are some others in that string of numbers--.18 etc. some of those are cased ambrotypes. i don't have much input into this database, but that image is one of mine. same with those ambrotypes.</p>

<p>Hi, maybe this is useful for you...<br>

http://predator.homedns.org/dag/</p>

<p>What about taking a photograph of the daguerreotype? I allready made some using a dark mask around my digital camera, so that the equipment is not reflected by the glas or daguerreotype. The source of light must be lateral. See my only photo in my portfolio, its a daguerreotype made with a hand made camera, not so perfect but...</p>