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banivechi

Using bellows for super macro coin photos

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I am a big fan of old Olympus OM cameras, I used to have up to 6 different models at a time (now I have "only" 3...). Not long time ago I purchased an old bellows system for macro photography, with a dedicated 50mm f 3.5 Zuiko lens. Not in very good looking shape, but fully functional, and I tested it once with one of my film cameras.

As a digital camera I have an Olympus e-620 wich I bought thinking about my good old zuiko lenses. I use them on my digital camera with an adapter.

Yesterday I adapted the bellows to the digital camera and I made some test shots on the coins with natural sun light.

The only problem is that there is no autofocus, so I spent some time with the "fine tuning" but I like the results so much that I posted the photos on my blog.

Today I photographed some more coins.

Next step will be the acquisition of a dedicated LED flash ring.

I would like to see your comments or suggestions.

http://numisfera.ro/poze-de-monede-cu-burduf/

http://numisfera.ro/poze-monede-cu-burduf-2/

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Love the results.

 

14-medium.jpg

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Beautifully done. The focus is truly problematic when using a bellows. I used to play around with it but was having too many vision problems to make a good go of it. However you've inspired me and I have new glasses for close-focus and now I have a new photo project for the coming week or so. :bthumbsup:

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Thank you!

Art,you can adjust for your eye the diopter adapter located near the wiewfinder on most of DSLR's and then you can attach a magnifier to the viewfinder.

Olympus has a thing like this named Varimagni :http://www.amazon.com/gp/product/B000FLIW9U/ref=olp_product_details?ie=UTF8&me=&seller=

As I know and Nikon, Canon, etc have similar focus finders available.

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Thank you!

Art,you can adjust for your eye the diopter adapter located near the wiewfinder on most of DSLR's and then you can attach a magnifier to the viewfinder.

Olympus has a thing like this named Varimagni :http://www.amazon.co...TF8&me=&seller=

As I know and Nikon, Canon, etc have similar focus finders available.

 

I am going to use some of my old film cameras in this project -- a few of them have the built in diopters but they didn't help much the last time I was playing with it. I do however have a nice "new" film camera that has all the bells and whistles so that's the one I'll start with.

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When you take photos at higher magnification, depth of field becomes a problem. With film cameras you pretty much needed to stop-down the lens until you got a reasonable DOF, and hoped that happened before diffraction caused the image to get too soft. But with digital cameras you can keep the aperture open, and adjust the focus a little at a time up or down to get a sequence of shots where each plane of the image is in focus. For coins at around 4x magnification, this is usually 3-5 shots. Then you can "stack" those together using a "focus stacking" program like Helicon or Zerene (or CZP, which is what I use, and it's free). This technique will allow you to keep maximum sharpness and contrast by avoiding diffraction effects.

 

Interesting thing about this technique is that you can then use microscope objectives on the bellows. A 4x NA=0.1 Achromat costs only US$25-$30 and gives very good results. Single images from such a "lens" will have poor depth of field since the aperture is so wide and not adjustable. But the sequence of images can be "stacked" to stitch all the in-focus parts of the image together.

 

Another interesting aspect is that you don't need to be as careful about focusing. Get as close as you can with the equipment, then move up or down until you are definitely out of focus, and start the sequence. Then move down (or up) in steps, taking shots at each step, until you pass through the best focus point. Then continue until you are definitely out of focus on the other side. Download the images, and look through them to find the first and last shot that has some part of the image in perfect focus. Delete all the rest that show nothing in focus. Then stack them with the program.

 

In my view, this technique brings the best of all available technologies, both modern and retro, to bear on the image-making process:

- Digital camera to capture and process the images quickly (modern)

- Bellows to allow fine adjustability of magnification and focus (retro)

- Highest quality microscope optics to give best sharpness and contrast (retro technology with modern optical standards)

- Software to combine in-focus parts of the images together (modern)

 

Now, if you absolutely MUST use film, you can still do stacking but you will need to scan the images first and then use the stacking program on the digital images. Probably won't give quite the same final quality but will still likely be better than stopping-down for depth of field and accepting the degradation from diffraction.

 

Here is a recent stack I did using a $25 4x / 0.1 objective on my Vivitar bellows, with Canon T2i. First three are the images to stack. Notice the field is in focus on the first one; the mintmark on second; and the tops of the digits of the date on the third. The composite shows all in focus.

 

IMG_0152_01.jpg

IMG_0153_01.jpg

IMG_0154_01.jpg

New-Out202_01.jpg

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Nice ... very dramatic demonstration. Thanks for sharing! :art:

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Sorry, I don't think I have any coins about with higher relief. Most of what I own are relatively modern US coins, all of which have fairly low relief. Bigger coins have higher relief but require less magnification, so on a % basis they are about the same. The only change that happens with higher relief is that more individual shots are required as part of the stack to get all planes in critical focus. I'll look around and see if I have anything appropriate...Ray

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Very interesting. Thanks for the info. I'll come back and reference it when I'm ready to start messing with this again.

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With just three images, does the particular stacking order matter? On one of the web sites I found, it seems like you need to make sure that you have a sequence of images where the focus is moving all in the same direction. But with coins, I don't think one would typically have more than 3 or 4 images to work with ... maybe only two? Is there a minimum number of images required?

 

CZP looks good ... too bad that it won't run on Linux, and although the software seems to be GPL licenced, it isn't open source AFAICT.

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I've read different accounts on stacking order but I've never tried testing it to see if it really mattered with CZP. Certainly with two images it won't matter, but not sure about 3 or more. First image in the sequence is taken as the reference, and all others are resized / shifted x / shifted y / rotated versus that one to line up critical features identified by the software. I've recently thought it might be best to have the image that has critical focus on the most important feature you are trying to show be the reference to keep it from suffering sharpness loss due to resizing, but have not tested that yet. The best images I've seen of coins have lots of images in the stack (often 30 or more). Many folks use a sliding focus rail called StackShot which has a linear stepper motor capable of very small step sizes, and run many shots. I adjust focus manually so can't achieve the extreme resolution and regular step size of a mechanical system like StackShot, so tend to make my stacks based on focusing particular features of the stack in the individual shots. This minimizes the number of shots but may result in a worse stacked image. I am not sure either way since I don't own a StackShot...Ray

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CZP looks good ... too bad that it won't run on Linux, and although the software seems to be GPL licenced, it isn't open source AFAICT.

 

I was able to install CZP (actually called "CombineZP") under Wine on Linux. Before it would run, I had to fix a couple of installation issues:

 

1. In the Wine configuration under the "Libraries" tab, I had to change the run order of "msiexec.exe" from "native,built-in" to "built-in,native" before the MSI file would install;

2. After installation, I had to copy a couple of DLLs from my Windows XP laptop to the Wine C:\windows\system32 folder: WMASF.DLL and WMVCore.DLL.

 

After that, it appears to run correctly. :) Haven't stacked any images with it yet, though.

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