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Dr PR

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  1. The Granado was an interesting ship. I looked in the Anatomy of the Ship book (The Bomb Vessel Granado 1742, Peter Goodwin, Naval Institute Press, 1989) to see what it had to say about these objects. Although there are many detailed drawings of just about every part of the ship - inside and out - I could find none for these parts. In the two page inboard drawing (page 54-55) the aft one is lost in the page fold and the forward one seems to be behind the mast. However, photos of the model on page 32 and 35 do show these parts, and in the close up photo on page 35 it does appear that the post is leaning forward (from bottom to top) slightly, as shown in the drawing Brain posted. I would call these things kevel blocks, and zu Mondfeld (page 163) even has a drawing of one angled as in Brian's drawing (Historic Ship Models, Wolfram zu Mondfeld, Sterling Publishing Company, New York, 1989).
  2. DZ, I don't see how anyone could find fault with that picture. It is a great photo of a very nice model. I still have my D200 body but I quite literally wore out the 18-70 mm lens. It had a rough life and I disassembled and repaired it three times over the years before getting a new 16-80 mm f/2.8 lens for newer camera bodies. John is right about depth of field being in the eye of the beholder. For the graph I posted above I just used the depth of field settings on the lens depth of field display. That will tell you it is an old (1970s) lens because the new auto everything lenses no longer have a depth of field display. The graph is by no means super accurate, but it serves well to illustrate the relationship between depth of field, focus distance and f stop.
  3. I take no offense either. The more opinions the better, and more facts are even better! Even after half a century of photography I am still learning and open to new ideas. I agree that I wouldn't try to use a long focal length lens (telephoto) to photograph a ship model (or anything else) if I was using photo stacking. Generally speaking, the best image magnification you can get on the photo sensor with most lenses not designed for close distance photography is about 0.25x (taken from Nikon lens data). So they aren't very useful for close-up photography. You have to back out to the minimum focus distance for the lens, but that isn't a problem if you are photographing the whole model. In fact, you will probably want to back off even farther to get the entire thing in the image. A macro lens can give you 1x magnification on the image sensor, so it is ideal for close up photography of small details. Even so, with an excellent macro lens you may not have enough depth of field at the focus distance to get one clear image, so photo stacking is very useful. Here are some examples: The image on the left is one of a series of photos of this cannon rigging, taken with the same lighting and f stop. Notice blurring of the far end of the port lid, the bulwark at the right and the close edge of the penny. The image on the right is the result of photo stacking several images shot with the camera at the same position relative to the cannon and different focus distances. All parts of the image are in sharp focus. So photo stacking is useful for small details shot close up with a macro lens. As Charles Green said, depth of field is proportional to focus distance. Here is a graph I prepared for a photography lecture using a lens I have: This lens has a very long minimum focus distance (about 15 feet or 4.5 meters) so it wouldn't be very useful for photographing ship models. But the graph clearly shows the relationship between focus distance and depth of field, and the effect different f stops have on depth of field. Higher f numbers produce greater depth of field. These relationships are true of all lenses, but shorter focal length lenses have much better characteristics at shorter focus distances. But the problem with backing out to longer focus distances to get a greater depth of field is that the photo subject becomes a smaller and smaller part of the field of view. So a longer focal length lens is needed (or longer zoom) to narrow the field to just fit the subject. My experiments with long focal length lenses several decades ago were intended to take advantage of the greater depth of field at longer focus distances and large f numbers, and still get enough magnification to include the entire subject in the field of view. The problem with this approach is that the long focus distances cause the setup to be more sensitive to slight vibrations. If you try this method you must have a far more sturdy camera support than afforded by most tripods and bright lighting. In one case I discovered that my heartbeat was causing regular expansion and contraction of my chest, and this was sending out slight pressure waves that were moving the image in perfect sync with my heartbeat! I had to use a long cable release and step out of the room!
  4. BS in Bacteriology (1968) and PhD in Microbiology (1978). Nuclear Weapons Officer in the US Navy (1969-72). I ran a medical mycology laboratory (1972-74) before entering grad school where I did research in enzyme kinetics and fungal physiology looking for anti-fungal antibiotics. While doing this in the mid 1970s I built a personal computer and wrote programs to crunch numbers from my enzyme kinetics studies. I also wrote one of the first screen-oriented word processors (Videowriter) that was used in typing training machines. Micro organisms or micro computers, what's the difference? After graduating with my PhD in Microbiology I was hired by Hewlett-Packard to develop software for a new desk-top computer that never went anywhere. Then in 1980 I joined a small electronics company and spent the next 35 years designing hardware and programming a wide variety of systems, from multi-processor microcomputers for automating plywood lathes to oceanographic instruments and metal detectors - and even an electronic puffin egg. Although I am now mostly retired I just finished six circuit boards for a medical response testing machine. For a hobby, other than ship models, I am photographing and drawing the native plants of Oregon.
  5. In the 12 photo sequence I posted above I did see slight image magnification changes with each different focus distance. I see this with image sequences using only a few photos. Photoshop has an "Auto-Align Layers" function that places all images aligned and rescaled so that the features in each image line up at the same size. Then the "Auto-Blend Layers" function does the photo stacking. I agree that the blurred parts of my image were probably not in sharp focus in any of the 12 images, but even when they are I often see blurry perimeters. As the focus distance changes the image magnification changes so the picture area in the first image (closest focus to the camera) is wider than in the last image (most distant focus from the camera). So not all images contain the same picture area. This means the outer parts of the stacked image may not contain any sharp images, so there is nothing there for the focus stack software to choose. I understand the use of a rail - I have three different units. But as was said, trying to use a rail on an object nearly two feet deep would be a lot more difficult than just putting the camera on a tripod and shooting a sequence of individually focused pictures. First, even with a good depth of field (high f number and long exposures) the camera would have to move more than a foot or more. If it was close to the model the image magnification (view angle)would change greatly from start to finish. This would be much more than by just refocusing the lens on a fixed camera. Rather than using a macro lens as I did, a longer focal length lens (telephoto) positioned several feet from the model would help with the magnification change with camera movement. I experimented with this a lot about 40 years ago and got good results with a 300 mm f4 lens. But it requires a very large/long work space. And a long rail. And a very solid vibration free work environment. This brings me to my point. Most of us are not photographing museum pieces, and we don't have the large photo studio with all the specialized camera equipment and long rails. So it isn't "better" for those of us who don't have it. **** One more thing. I have been pretty successful hand holding my camera and macro lens while photographing wildflowers outdoors - and photo stacking multiple images to get a great depth of field. Everyone says you can't photo stack hand held images, and they are wrong. Photoshop's "Auto-Align Layers" does a very good job compensating for small camera motion differences. It works most of the time if you know what you are doing - and there isn't a lot of breeze blowing the flowers! Most, but not all of the time. But if you don't try it it fails every time.
  6. Focus stacking is a lot of work, both in taking the series of images and in combining them into one image. But it yields images you can't get any other way. I use it often when photographing wildflowers and in photographing ship models. Here is an example: Note that you can see the grain in the end of the bowsprit dowel, and in the masts, and in the planks in the transom. The distance from the tip of the bowsprit dowel to the end of the boat davits on the stern is 22 1/2 inches! The camera lens was about 6 inches in front of the end of the bowsprit dowel. I took a series of 12 photos, each focused upon parts of the model at successively greater distances. I was careful to ensure that each photo's depth of field overlapped the previous photo so there were no blurred ranges in between. I used an excellent macro lens for the pictures - a Nikon 105 mm f/2.8 macro lens designed especially for close up images with a great depth of field. The 12 photos were taken into Photoshop and placed as layers in a single file. Then I used the "Auto-Blend Layers" function to combine them into a single image. The program selected the sharpest parts of each layer and cut out the blurry parts too close or too distant to be in the focus range. Then they were all combined into a single layer. It is a pretty good picture, but the process isn't perfect. Notice on the lower left that near the edge the planks are blurred. I have see similar blurring near the edges of many stacked photos where the program can't decide what parts are the sharpest. But still the image is far better than what you can get with a single exposure, no matter what camera and lens you are using. It took about an hour to take the pictures and edit them in Photoshop.
  7. I think a beginner should build first and read later! What do you want to do, read a book or build a model? If you are building a kit you don't need to read anything more than the kit instructions. Well, maybe. I have never seen a kit with really complete instructions, but you can get by. And you can always ask for help or advice here. There is great satisfaction from completing your first build. But if you get sidetracked trying to learn every detail of every part of ships, through all ages, and all nations, you will never get anything done. And beginners need that first build to learn if ship modeling is really what they want to do. If not they can still read the books if they are of interest. Maybe research is really what they will want to do, without wasting time building a model! The first build will not be a museum piece. It will be a learning experience. You learn about the materials - wood, plastic and metal. You learn about paints and glues. And you learn what tools you need and how to use them. And in the process you will have questions, and that leads to research. But one topic at a time, and as you need the information.
  8. Tewhano, Welcome aboard mate! Glad you found my posts useful. Have you seen my Okie Boat web site? https://www.okieboat.com
  9. Richard is correct IF you are building "to scale" in all details. Many models are not built this way. Short pieces work best on a plank on frame model with dozens of closely spaced frames. The frames are relatively wide and closely spaced to give the planks the proper hull shape. You can also use actual ship building techniques for "stealers" and hooked planking. If you are building a plank on bulkhead model (most kits) with just a few widely spaced bulkheads short planks create two problems. One, the bulkheads are fairly thin on edge, giving little room for glue. This is especially true where you are trying to join two planks end-to-end on a bulkhead. Due to the curvature of the hull the plank ends will try to pop loose, especially on sharper curved sections of the hull. You can always attach additional wood on either side of the bulkhead to give a larger gluing area for the plank ends. Two, if a plank end attaches to a bulkhead on a curved part of the hull, the plank will try to run straight line to the next bulkhead and will not follow the true curvature of the hull. Where two planks butt together at a curved part of the hull they will not form a smoothly curved strake, but will have a sharp "kink" or "knuckle" at the bulkhead. This will not match the curvature of the adjacent planks. If you try to sand this junction to a smooth curve you may sand all the way through the planks at the join - this is not good! I have built several plank on bulkhead models using full length planks from bow to stern. It is tricky trying to get the proper width and curvature at the ends, but it isn't hard if you are careful while shaping the pieces. You will have to include stealers near the stern on most models. I think using short planks on plank on bulkhead models is just asking for trouble. Also, some kits do not have enough bulkheads, usually midships. This leads to flat areas on the hull between the bulkheads even if you use full length planks. If any two bulkheads are spaced more than 2 inches (5 centimeters) apart you should consider creating a new bulkhead midway between them. This isn't hard to do - just duplicate the widest of the two existing bulkheads, fasten it in place, and shape it to size with a sanding block. This will ensure the proper curvature for the hull surface. Jacek's suggestion of using two shorter planks instead of one long plank is a good idea, but be sure to place the butt joints near midships, and do not place the joins at the same bulkhead on adjacent strakes. Like he says, it is easier to just work on the bow and stern curvatures on separate planks than on one long plank.
  10. Tim, That traveler looks great! I have been debating whether to use a traveler on my Baltimore clipper. I have looked at dozens of plans and photos of schooners and it seems some use a traveler and some don't. That brings up the question of when and why a traveler is used? One school of thought is that the traveler allows the position of the sail to be adjusted to meet wind conditions. But some people say this is not correct. The other school says the traveler on the jib boom was used to haul the sail back to the bowsprit where it was easier to reef the sail. When the sail was being flown it was hauled out to the end of the jib boom. I am leaning toward using a traveler just because it adds detail to the model.
  11. I posted a bit about anchor handling in small ships here: https://modelshipworld.com/topic/27410-small-ship-anchor-handling/?do=findComment&comment=787942 A line or chain called a shank painter was looped under the shaft at the flukes (crown of the anchor) to support the stowed anchor, and the ends were secured to timber heads or cleats on the rail or bulwark. A stopper rope to support the stock of the anchor was secured to the cathead on one end, looped through the anchor ring and then the free end was looped around a cleat or secured to a timber head. The anchor tackle could be loosened or removed and the stopper supported the head of the anchor. Apparently on some ships the anchor cable was removed from the anchor when at sea and stowed below decks.
  12. I do not have a lathe (on my wish list, but first I need a shop to put it in) so I have come up with a very simple way to make sheaves down to 0.078 inch (2 mm) diameter using ordinary brass washers. In this link I made sheaves for a 1:48 scale model: https://modelshipworld.com/topic/19611-albatros-by-dr-pr-mantua-scale-148-revenue-cutter-kitbash-about-1815/?do=findComment&comment=616985 For a list of brass washer sizes see this link: https://www.mcmaster.com/standard-washers/material~brass/
  13. Tim, I'm not sure about using the bolt ropes to produce "skeleton" sails. I haven't seen a model rigged that way but it does seem a bit odd (unusual) to me. However, I have seen models where some of the sail rigging is included without the sails. For example the fore sails have halliards and inhauls/downhauls that can be hooked together when the sail isn't rigged (usually at the inhaul block on the bowsprit/stay). Likewise square sails have clew lines and sheets that can be hooked together at the end of the spar. Gaff sail outhauls and brails can be rigged this way at the end of the boom. Buntlines could be hooked to the spar. I'm not sure what you would do with bow lines that normally attach directly to the sails. I think you can include most of the sail rigging in this way.
  14. I have been following this discussion because I went through a similar search a year or two back. Wolfram zu Mondfeld's Historic Ship Models (Sterling Publishing, New York, 1989) shows the construction of gun ports (page 96) and gun port lids (page 176) in pretty good detail. I realize many modelers play down Mondfeld's book because it isn't specific to any particular ship or nationality, and he doesn't list his references. This is true. But the book's greatest virtue is the descriptions of parts of ships as they evolved over the centuries and in different parts of the world. For example, he describes gun port lids for British, French and other Continental navies from before 1550 through 1890. Much of what this thread is about is discussed in his book. The book isn't perfect, but it does explain many of the differences you see in contemporary models from different nations and time periods.
  15. Looks like you turned a sow's ear into a silk purse! Hope you can continue with the Dapper Tom. I love the topsail schooners.
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