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Solution to 39mm to 52mm Macro Coupler?

Started 9 months ago | Questions thread
BBbuilder467 Veteran Member • Posts: 7,057
Re: Solution to 39mm to 52mm Macro Coupler?

MacM545 wrote:

3D Gunner wrote:

BBbuilder467 wrote:

My point is the need for a functional mock-up for the OP. I'm not going to design it for him. If the mock-up works, use it. I have a $125 minimum fee.

I can help him for free, just for fun, but I'm still not sure if it's worth the effort (in terms of the quality of the result) for a ~3mm gain in distance between the lenses.

I should order the parts, cut them at a lathe that is in another location and make an international shipment (more expensive than the parts themselves)...

He could do some tests to see if it's worth the effort or not. The technical solution exists.

So, we're waiting for his opinion.

................................................

I just did some measurements. The difference would be ~7mm, not ~3mm. 7mm may have some influence on quality, but still need some tests.

Honestly, I'm not sure what to say right now, although that really is appreciated! I did some test by basically holding the front lens in front of the telephoto. The front lens I set to F/4 while the distance between lenses was likely 8-11mm. I was able to get excellent image quality. I might need to do something to be able to get the lenses closer together, safely, which I should be able to do here soon, in order to see what difference it's able to make. Even with the somewhat large gap, it seemed to me that there was good image quality although I might need to see if that's true with the smaller apertures.

You're main concern was vignetting and you've proven it works. The reverse lens is the diopter. You can't stop it down or the main lens will see it.

A 23mm lens should be a +44 diopter when reversed. How will you even measure the image size to see if the adapter length is accurate. If the adapter and step-ring work, just use it.

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