Jump to content

rory_clague

Members
  • Posts

    7
  • Joined

  • Last visited

Reputation

0 Neutral
  1. <p>Here is a crop of the above image:<br> <img src="https://farm1.staticflickr.com/279/19762456094_1ecd69805e_o_d.jpg" alt="" /></p>
  2. <p>If you can scan at 4000 ppi or higher, that is preferable in my experience. Scanning at lower frequencies may capture all of the image details, but there is more to a film image than simply the image details. The texture and granularity of film looks more pleasing when scanned at higher resolutions. A lot of what people have come to expect from film over the last 15 years, in my opinion, is due to nothing more than grain aliasing artifacts aggressively sharpened in post-processing. At lower frequencies, grain aliasing becomes harsher. If you scan at high resolutions, it becomes less visible. The result is that you end up scanning at a resolution that is higher than the spatial resolution of the film, but the grain becomes more pleasing - even finer, in my experience. Tri-X is rated to 50-100 lp/mm. I scan routinely at 116 lp/mm (about 5900 ppi), and find the grain looks better and the fine details look *fine* as they should, compared to when I scan at 80 lp/mm (4000 ppi). At 4000 ppi, the finest details are visible, but they look thicker and blockier than they do when scanned at higher resolutions. I imagine 8000 ppi scans are even better in these regards, but I don't have the means yet to sample at those frequencies.</p> <p>So, the bottom line is, oversampling a negative produces better results, even if you aren't necessarily getting more information about the scene. You *are* getting more information about the medium, and this seems to reduce artifacts.<br> <img src="https://farm1.staticflickr.com/528/20337538611_abc8cb0e6f_k_d.jpg" alt="" /></p>
  3. Daniel, I'm glad that black and white film is thriving as a niche. Most of what I shoot is black and white. However, I hope colour film survives, too. I don't think the death if colour film is s good thing. How else are photographers going to get colour landscapes with the 4x5 and larger formats that still provide the highest resolution single shot colour photographs possible? I am committed to black and white as well as colour film. An Ilford-like company with a commitment to colour film would be great.
  4. <p>Hi Etienne, sorry for all the details! I kind of want to use my own post as a guide for myself and for others who might want to try the method. I do set the curves individually for each negative. I tried making a preset a couple of times, and I find that this just never works to my satisfaction. I imagine variables in development, density, and other issues change the relationships between how a digital camera "sees" the negatives and therefore what correction factors should be applied. I do make some 'darkroom' choices in this process that aren't strictly the same as what a scanner would choose, or what an optical printer of a color negative might do. Of course, the only reason we regard a scanner's choices as somehow privileged is that the scanner's software is using a preset, albeit a very good general preset that the scanner and software engineers worked very hard to optimize. I simply find that doing my own optimization for each image works out better for me. It takes a bit of time, but not all that much, and for me it's part of the fun of using a hybrid process. If I were using an enlarger, I would have fun playing around with the prints I could get by making choices there, too (and I do definitely plan on getting a color enlarger someday).</p> <p>Anyway, to blabber on some more, I'll just share my processing workflow right here for the record. Here, I'll just show the process I chose for an unremarkable shot I took of a friend with 35mm portra 160. From my DSLR scan, I had 10 digital raw images of the 35mm negative. With a 5D3 or D800 series, I could have fit the negative in one image at 1:1, of course. I like to sample as much resolution as possible, which is why I put as many pixels as possible onto the negative. I've found since I did this that 6 or even 4 shots is enough for a negative with APS-C. I did way too much overlap early on to try to optimize the stitching process with Microsoft ICE. So, to start, I choose an image that has a good view of my main subject, or an image that has a wide variety of colors and densities. All of my processing is done in DxO Optics Pro, but other raw converters have the same tools and the same workflow will apply in Lightroom, ACR, and other converters.<br> <img src="https://farm8.staticflickr.com/7610/17267691465_d8e6d5ce27_o_d.png" alt="" /><br> The first thing I do is account for small defects in the 7D/100L combination used for digitizing the negative. So, that means in DxO I turn on noise reduction, distortion correction, vignetting correction, chromatic aberration correction, and DxO lens softness correction, which applies sharpening to a raw file in a way calibrated to your particular lens. I usually turn up the sharpening very slightly form the default settings so that the grain looks sharp. Of course, you don't have to do this. I want the grain sharp, but not harsh, so I also typically turn down the microcontrast to -30 or so. Since the pixel density with this approach is quite high, the overall microcontrast of the image isn't negatively affected too badly. It just renders the grain a bit less harshly. See settings on the right panel. Again, other software packages like LR have these corrections.<br> <img src="https://farm8.staticflickr.com/7601/16645242384_b9cb35c107_o_d.png" alt="" /><br> Next, I choose a white balance that I will use for all of the raw images in the collection. I choose this by using the white balance selector to click on a few different "white" (or "clear") pixels in on the edge of the negative. This compensates for the brown-red color of the film backing. I click on a few different locations in this white area and select a Kelvin temperature and tint that is roughly the average of all these clicks. In the case of this image, it was roughly 3100 K and -20:<br> <img src="https://farm8.staticflickr.com/7675/17267164361_218b79cb81_o_d.png" alt="" /><br> I then select all the images, and apply the same white balance settings to all the images. It's important for this workflow to do this before manipulating the R, G, and B curves.<br /><img src="https://farm9.staticflickr.com/8742/17080143370_9061e56c3f_o_d.png" alt="" /><br> Next, I go back to the image with the best view of my main subject. I then look at only the red histogram and turn on the red curve. Note how the red histogram shows all the pixels in a small region of the histogram. What I want to do is map those pixels with the red curves tool so that they are spread out over the entire luminance range.<br> <img src="https://farm8.staticflickr.com/7649/16647471753_f469fcb32d_o_d.png" alt="" /><br> The first step is to simply invert the red curve, like this:<br> <img src="https://farm8.staticflickr.com/7690/16645240904_090241beab_o_d.png" alt="" /><br> Now the red highlights in the negative are now in the shadows in the positive. The histogram, though, still looks compressed in one small region. Now I use the curves tool to remap where the white and black points are for the red curve. After this, the histogram for red should be distributed over the entire luminance range. Be sure not to extend it too far. You want the brightest red pixel to be remapped to 255,0,0 and the darkest to be remapped to 0,0,0, but you don't want the second-brightest red pixel to take on this value instead, or you will get blown highlights and clipped shadows. Now you can see that the red curve has a very distinct shape:<br> <img src="https://farm9.staticflickr.com/8775/17267163191_0fc6a4aeeb_o_d.png" alt="" /><br> Next I do this same process with the green channel. First I invert the green curve:<br> <img src="https://farm8.staticflickr.com/7606/17265906942_c9b8f8ef07_o_d.png" alt="" /><br> Then use the green histogram as a guide to remap the tonal values of the green channel over the entire luminance range using the green curves tool:<br> <img src="https://farm8.staticflickr.com/7673/17267162001_f587b8e63a_o_d.png" alt="" /><br> Then I do the same thing with blue. First invert the blue curve:<br> <img src="https://farm9.staticflickr.com/8735/16647469383_2d3623ecd6_o_d.png" alt="" /><br> Then remap so that the histogram is distributed across the luminance range. Interestingly, you can see the blue channel requires less remapping than the green channel, which requires less remapping than the red channel that was originally quite compressed in the negative:<br> <img src="https://farm8.staticflickr.com/7584/17081480429_6e392dc806_o_d.png" alt="" /><br> Now that the white and black points are set for each curve, I usually introduce a slight bulge in the middle of each curve, along the axis of the original white luminance (or RGB) curve. This brightens the midtones slightly and, depending on the magnitude of the changes, applies slightly different weights to each of the R, G, and B curves. This is where aesthetic choices become somewhat significant. Usually the red channel has the strongest curve, followed by green, followed by blue. Sometimes, the blue channel even gets a negative curve. In this case, the blue channel was left mostly flat. Finally, I will sometimes modify the combined RGB curve to make the exposure what I want. These steps are not necessary, but I find they always improves the look of the image:<br> <img src="https://farm8.staticflickr.com/7624/17267696565_2bea055772_o_d.png" alt="" /><br> Finally, in DXO, I copy the correction settings (which includes the curves manipulations) and paste them to all the images that will be stitched to form an image:<br> <img src="https://farm8.staticflickr.com/7725/17267686685_bdcbca94fb_o_d.png" alt="" width="1920" height="1080" /><br> Then export as 16-bit TIF files. I've tried exporting as DNG files, but somehow Microsoft ICE doesn't read the curves functions I applied and the resulting colors are a real mess. Therefore, I stick with TIF files. If you aren't as crazy as I am, you could just use jpegs, too:<br> <img src="https://farm9.staticflickr.com/8785/17267159931_4c47288530_o_d.png" alt="" /><br> Finally, I use Microsoft ICE and drop all the TIF files, choose planar with skew, crop out the black frame around the edges of the image, export as a TIF file, re-open the TIF in DxO, and use the clone stamp tool to deal with dust. Then I'm done. It sounds like a lot of work, but it is really quite fast once you get the hang of it.<br> <img src="https://farm9.staticflickr.com/8704/17241711466_ebcb258262_o_d.png" alt="" /><br> Finally, you have a finished image that looks okay. Black and white is very simple compared to this. Just convert to greyscale and invert the combined RGB curve rather than the R, G, and B curves individually. Introduce an S curve or not depending on preferences in order to get some more contrast. Since black and white film has a higher density range than color negative film, remapping the tonal values isn't usually necessary. Same goes for positive film (which is the easiest of all - I don't change the curves at all with color positive film).<br> <img src="https://farm9.staticflickr.com/8744/16744482008_37daae7b5d_o_d.jpg" alt="" /></p>
  5. <p>I use this method and get good results. I use a Canon 7D and a 100mm macro lens. A D7200 or D5300 and a 1:1 Nikon macro lens would be ideal for their combination of dynamic range, pixel density, and lack of AA filter, although the AA filter may inhibit grain aliasing.</p> <p>10000 x 10000 stitch here:<br> <p> </p>
  6. <p>One more thing, as noted above, be sure to use a remote shutter release and mirror lock-up or live view. I always re-focus for every frame I take of the negative, as well. </p> <p>As the images above didn't seem to post, here is another try:<br> <img src="https://farm9.staticflickr.com/8755/16776019509_df5c4671ef_k_d.jpg" alt="" /><br> <img src="https://farm9.staticflickr.com/8580/16441147657_71901d6890_k_d.jpg" alt="" /></p>
  7. <p>Hi, I use a Canon 7D and a 100mm f/2.8L macro lens for 1:1 magnification. I prefer the APS-C sensor to my 5D3 for this work, actually, because I can get a higher pixel density and therefore less problematic grain aliasing this way. It comes out to something like 5900 ppi rather than 4000 ppi (as the 5D3 is). The problem with this approach is that it requires more images to cover 120 film (about 24 images) and even 35mm film (requires 4-6 images). With the 5D3 I can get 35mm in 1 image and 120 film in 6-8 images, depending on how much overlap I want. The 5Ds will give me the pixel density I want, but the ability to stitch fewer images. Of course, another potential problem with using a full frame camera with this approach is lens edge sharpness. When using an APS-C sensor camera, I use the best part of the 100mm macro lens. <br /><br />My rig consists of securing the 7D onto a tripod with two settings for the legs, one for a tall orientation with the legs close together, and one with the legs spread far apart, which puts the camera closer to the floor (or ground). I use the latter setting, and extend two of the legs by 2 segments, and a third leg by 3 segments. The long segment I secure underneath a couch. I then press down on the tripod head so that the legs are very secure and don't move. Now the tripod is oriented at an angle, i.e. it is not extending at a 90 degree angle with respect to the floor, but rather something like an 50-60 degree angle. I then place the camera on the tripod head so that the lens is pointed straight at the floor. I place a heavy textbook that is something like 4-6 inches thick on the ground underneath the lens. I check the alignment of the lens with the book by placing a mirror on the book. I look through the viewfinder at the mirror at check that the lens is in the exact center of the viewfinder (as reflected by the mirror). This ensures that the lens is exactly orthogonal to the surface that the film will be placed on. I remove the mirror from the book and place an Artograph lightbox on top of the book, and turn it on. Any LED light box with even illumination of the surface will work. I place the film on the lightbox and place a couple of heavy glass plates (they happen to be coasters in my case), but any flat heavy object or even a really good slide holder will work. I don't bother masking the film or anything, but the glass plates are merely used to keep the film flat on the surface of the light box. Of course, the light box must be perfectly clean and dust-free. I keep a blower handy and have a steam humidifier set up next to the work area to minimize dust. Finally, I adjust the location of the camera as well as the focus so that the lens is as close to the film as allowed by the macro lens while maintaining focus. I then set the aperture to 5.6, the ISO to 100, and the shutter speed to whatever gives me a histogram in which the shadows are as bright as possible without the highlights being clipped. I use the highlight clipping warning on the 7D to check this. With black and white film, there is just enough density range to cover the entire histogram. With color negative film, the density range is quite compressed and the histogram usually occupies a small area of the dynamic range of the sensor. With positive film, bracketing is necessary to cover the density range with a Canon sensor. With a D800, this is less of a problem. <br /><br />Once I have chosen a shutter speed, usually 1/5 to 1/10, I use live view to focus on the grain at 10x magnification, and I scan the whole imaging area to be sure all the grain is in focus across the image. If it is not, that means that the lens is not aligned with the negative. Usually because I use the mirror, this is not a problem. I use f/5.6 because the 100mm f/2.8L is sharpest at that aperture. I then take an image. When I want to scan around the image, I simply move the light box around on top of the text book. Alternatively, you could move the text book itself. I then take up to 24 images with 120 film, and up to 6 with 35mm film. I use the raw format for all of these.</p> <p>To process, I open the raw files in DxO Optics Pro and use the distortion correction, vignetting correction, and softness correction to be sure all the images stitch together well. For black and white I convert the images to greyscale. It is important that all the images have the same white balance setting for color negative film, and all the images to be stitched together must have the same exposure corrections applied. I usually adjust the microcontrast setting (clarity slider in Lightroom) to my liking. I don't apply any USM sharpening - rather, the DxO lens softness correction does all the sharpening I want. Finally, I convert the negative to a positive using the curves tool. With black and white, I simply invert the RGB curve so that it moves from the upper left to lower right corner rather than vice-versa. For color negative film, I adjust the R, G, and B curves individually, leaving the RGB curve alone. I use the R, G, and B histograms separately at this stage, and basically you want to slide the R curve in such a way that the red histogram is distributed throughout the entire luminance range rather than squashed together. You want to do this for all three curves. This usually makes the color look great. For black and white film, I apply a bit of contrast by introducing an S curve into the RGB curve. It's very important for color negative film that you select the same white balance for all 24 of the images to be stitched, and apply the same curves corrections to all images.</p> <p>I export each of the images from RAW to 16-bit TIF. I then use Microsoft ICE to stitch the TIF files together. I choose the planar with skew setting, crop to my liking (usually getting rid of the black frame around the image), and export as both a TIF for printing and a jpeg. I then open the TIF back up in Photoshop or DXO and use the clone stamp tool to deal with any pieces of dust I missed.</p> <p>For color negative film it's important to prevent Newton rings. This can be achieved by not dusting the light box off too much before applying the film, as it causes a charge to build up. I've never noticed Newton rings form with my 120 film.</p> <p>The results are a good resolution scan. I was verbose above, but the process does not take any longer than 2-3 minutes per picture, and I think the results are good enough for me. The camera's AA filter as well as the small pixels help prevent grain aliasing.</p> <p>Check out full-sized 13200x13200 images on Flickr:<br> http://www.flickr.com/photos/126351313@N08/16660912378/<br> <img src="http://www.flickr.com/photos/126351313@N08/16656069705/" alt="" /><br> http://www.flickr.com/photos/126351313@N08/16441147657/<br> <img src="http://www.flickr.com/photos/126351313@N08/16441147657/" alt="" /><br> http://www.flickr.com/photos/126351313@N08/16660912378/<br> <img src="http://www.flickr.com/photos/126351313@N08/16660912378/" alt="" /><br> http://www.flickr.com/photos/126351313@N08/16272310908/<br> <img src="http://www.flickr.com/photos/126351313@N08/16272310908/" alt="" /><br> http://www.flickr.com/photos/126351313@N08/16272310908/<br> <img src="http://www.flickr.com/photos/126351313@N08/16272310908/" alt="" /></p>
×
×
  • Create New...