Focus versus Rail stacking Poll

deanimator wrote:

mawyatt2002 wrote:

deanimator wrote:

RobinHsherwood wrote:

xpatUSA wrote:

deanimator wrote:

xpatUSA wrote:

c h u n k wrote:

xpatUSA wrote:

deanimator wrote:

I use microscope objectives, so I don't have a choice. I HAVE to use a focus rail, in my case a Wemacro.

Thanks, I wasn't familiar with that genre. I should have made it clearer that I'm talking about simple objects like flowers, bugs, small artifacts, etc.

Many people use objectives for all of those subjects.

Pardon my ignorance but I don't understands "objectives". Are they the so-called close-up filters or the likes of the Raynoxes?

Neither. Google a picture of a microscope. Those cylinders protruding from the turret of he microscope are lens assemblies called "objectives". As a general rule, they have neither integral focus nor aperture mechanisms.

I see. So the "Many people" who "use objectives for all of those subjects" have gone out and bought fancy microscopes to shoot "flowers, bugs, small artifacts, etc".

I can't say that there is no 100:1 macro lens. I can say I've never heard of one. That's strictly the domain of microscope objectives... and electron microscopes.

I sense deliberate obfuscation, please desist ...

Ted,

It's NOT obfuscation, but an attempt to supply valuable information.

The many people mentioned do not buy fancy microscopes, but instead use one type of microscope objective directly mounted upon either extension tubes or bellows as shown below;

A 4X microscope objective mounted on extension tubes.

A 4X microscope objective mounted on bellows.

Another type of microscope objective requires the use of a 'tube lens' in order to focus the image, these tube lenses are usually medium telephoto (100-200 mm). Shown below is a 4X microscope lens of this infinite type, mounted on my 100 mm Macro lens.

A 4X infinite type microscope objective mounted on a 100 mm Macro lens.

I hope these illustrations provide some clarity to the discussion. If you require more information about this fascinating area of macro photography, please just ask.

How well does the infinite objective do with the 100mm macro lens as the tube lens? I've heard conflicting recommendations for and against.

As you probably know from the PM site, but maybe helpful for others this hasn't shown to be a exact science!!

The usual 100mm macro lens vignette when used as a "tube" lens for quality objectives like the Mitutoyo inf. 200mm types. When I tried my Nikon 105mm VR and 70-200mm VR set to 100mm, the results were poor. The 70-200mm works well at 200mm but not 100mm.

I purchased a Rokinon 135mm F2 a couple years ago because the IQ from this lens is superb, stunningly sharp on a Nikon D800E or D850 (not a total surprise since this is likely a direct copy of the Zeiss 135 F2 design). Used as a "tube" lens the results were dismal, however it did perform well when used as a stacked lens combo with a good 50mm for 2.7X work.

So it's generally best to experiment rather than try to figure out what works well and what doesn't, but the shorter FL lens tend to vignette with inf. corrected 200mm objectives like the Mitty's.

Best,

I have a 100mm Tokina macro plus several zoom lenses to try when I finally have an infinite objective. The truth is that I trust Wemacro, and since they have a turnkey Raynox solution, I'll probably go that route.

You can't go wrong with the Raynox 150 or 250, they are both superb as tube lenses. The Wemacro turnkey Pro Raynox setup looks very intriguing indeed!!