Another Cheap 4x Objective

This was taken with my Canon T2i...Ray

Yes, please share or I'll whine...

No problem, I just got a new puppy so I am used to it.

I worked with a guy on another forum to set him up for 4x variety shots, and he's doing very well with it. He's shooting Nikon, which forces a different lighting and exposure technique that I'll discuss later if needed.

The simplest setup to make work, and the one I've been using recently, is as follows, from top to bottom, with effective extension in parentheses:

Canon T2i (44mm)
EOS-M42 adapter (2mm)
M42 extensions (35mm)
M42 focusing helicoid (17-30mm)
M42-RMS adapter (55mm)
RMS 4x objective

The total extension for this setup, including camera register distance, is 44+2+35+(17-30)+55 = 153-166mm.

The expected extension for most objectives is 150-160mm, so this puts you squarely in the range to get very close to their rated magnification.

I mount the camera on a rigid stand but you can also just mount it on a tripod.

For the PL 4 objective I linked to above, the working distance is long enough (~17mm) that you can use Jansjos for lighting.

The technique is pretty simple:
- Assemble the setup
- Adjust height of stand or tripod so the objective is about 20mm above the coin
- Adjust the focusing helicoid until you just start to have the high points of the coin in focus
- Make note of the position of the helicoid. Mark in pencil if needed
- Adjust the lights to give the shadow detail, highlights, and overall illumination you desire
- Adjust the helicoid until the lowest points of the coin are in focus
- Make note of the position of the helicoid. Mark in pencil if needed
- Snap the first shot
- Adjust the helicoid approx 20% toward the first mark
- Snap the second shot
- Continue adjusting/shooting until you reach the first mark

The above will give you 6 images at various focal planes. You now need to use a focus stacking program such as CombineZP (CZP) to merge the images into one fully-focused image. I can give a step by step for that process in another installment.

Here are links to the items I recommended to the guy on the other group.

4x Nikon (but the PL 4 will work almost as well and is cheaper)
http://www.ebay.com/itm/Nikon-4X-0-...em43b72bf513

Set of M42 extensions:
http://www.ebay.com/itm/Camrea-Macr...em2ebd7be226

Cone-shaped M42-RMS adapter:
http://www.ebay.com/itm/Zykkor-Lens...em3371c0ba24

M42 focus helicoid:
http://www.ebay.com/itm/New-M42-to-...em3374338940

EOS to M42 adapter
http://www.ebay.com/itm/For-Black-A...em51a7aa2862

So to do this it will cost $45 + $8 +$30 +$58 +$5 = $146 total for Nikon, or about $116 for the PL 4 objective.

I need to note that the helicoid distance between first and last shots (high and low points) is actually pretty small, too small to really make the marks I talk about above. Technique is still the same, but the 20% steps are a bit arbitrary. You just need to try and space it out between first and last shots best you can to get enough shots. There is another method as well that works, which is to focus on the things you want to be in focus and snap the shots there, rather than trying to make even steps. Both methods work.

Yes, exactly. I was working with a couple guys on setting up the objective mounting and they wanted to stick with the copy stand that was working for them for full-coin shots. The extension + helicoid + cone adapter was the best solution I could come up with that allowed them to use all their existing stuff. There are so many possibilities to aid in focusing that I find each person I work with needs specific assistance with their method and how to work with their existing equipment. I also keep trying new stuff myself and so my recommendations change over time. At this point, my preferred methods for variety shots are:

1) Camera on microscope stand with fine adjustment stage (this is the setup you show above)
2) Camera on microscope stand with fixed stage (this is the setup I show in many posts)
3) Camera on copy stand with fine adjustment stage (but the fine adjust stages are expensive)
4) Camera on copy stand with helicoid and extensions (the setup I recommend in this thread)
5) as #4 but with a tripod

So while the setup I'm recommending in this thread is not my top recommendation, it's the most accessible by folks who already have a copy stand and just want to add variety capability.