Advice on shooting microchips with EXTREME detail.

Started 6 months ago | Discussions thread
mawyatt2002
mawyatt2002 Regular Member • Posts: 293
Re: First shots - and a few questions.
1

RobinHsherwood wrote:

mawyatt2002 wrote:

RobinHsherwood wrote:

mawyatt2002 wrote:

RobinHsherwood wrote:

Steve Dorsey wrote:

I have a Canon 70-200 F4 and a 70-200 f2.8. Would either of those work, or am I looking for a different sort of thing altogether?

These may work at the 200mm setting, however I'd use the primary glass as recommended by Mike.

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Robin H

Robin,

The old primary mentioned (Nikon 200mm F4 "Q") are very reasonable on eBay (got 2 for less than $70, but needed to be converted to modern F mount). I have a Nikon 70-200 F2.8 VR1 and the 200mm "Q" is a better tube lens. Awhile back I purchased the stunningly sharp Rokinon 135mm F2 in hopes of a great tubes lens. This lens is the sharpest conventional lens I own, probably a direct copy of the modern Carl Zeiss 135mm (not the older 135mm F3.5 I mentioned). As good as it is at the intended use, it's a poor tube lens, but a pretty good base lens for stacked lens use with a reversed 50mm F1.8 at 2.7X. The old Vivitar and old Zeiss 135mm F3.5 are better tube lens. Many others over at Photomacrography.net have struggled with what will make a good tube lens, but the general consensus is trial testing is the best solution at this time.

Best,

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~Mike~

Mike,

I have heard that the old Pentax Takumars work well also.

As an old retired microscopist, I would agree with the general consensus on testing! For my part, I have a large investment in finite objectives and microscopes for them, so infinite objectives are not on my list. For 0.5x to 40x, I use Zeiss Luminars on bellows as direct macro lenses. For anything higher then that I revert to photomicroscopy.

Best...

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Robin H

Robin,

Mark has a great site for lens evaluation over at Coinimaging.com. The reason I mentioned the lenses I favor at different magnifications can be seen from these plots from Mark's site. This is old data from a Nikon 200 camera body and doesn't include the Mitutoyo's which are much better than the Nikon PlanAPO shown above 3X. As mentioned I favor the 55/2.8 Nikkor around 0.5X, the Nikkor PN105 F2.8A up to 2X, the Canon 35mm up to ~3.2X, then the Mitty's take over.

An interesting thing about the Nikon PN105 F2.8A is that it's highly optimized for 1X as shown in the corner sharpness (it can out-resolve my D500 or D850 at 1X). Lou over at Photomacrography suggested and demonstrated that the optimization point could be moved away from 1X by use of a 1.4X teleconverter, since the optical lens formula would still be working at the design center of 1X, but the image magnification would be 1.4X. I took Lou's advice and tried this at 1.4, 1.7 and 2X with appropriate teleconverters, with very good results.

I know this might be a little too scientific for most, but with your background you'll certainly see why my lens selection favors these lens at various magnifications. Even with the best lens selection, the proper lighting for high resolution chip images is a very difficult task within itself, and the elimination and reduction of vibration becomes a never ending endeavor!!

Best,

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~Mike~

Thanks for the info Mike, I'll absorb it and cogitate!

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Robin H

You are welcome.

Now I'm off to finishing up the design and test of a electronic trigger system which will allow multiple studios strobes to be triggered from my stacking rail system with the cameras (D500 & D850) operating in Live View with EFCS.

Best,

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~Mike~

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