Another Newbie question.

[pinhole]

Concerning objectives. What is the difference between a PLAN & an INFINITY PLAN objective??? Thanks folks, pinhole

[johan]

An infinite objective requires another optic in the optical path to make photos whereas a non-infinite plan does not. Frequently this other optic required for infinite objectives provides correction of some form.

[ChrisR]

What is the difference between a PLAN & an INFINITY PLAN objective???

Plan means flat field.
"Infinity" means it's designed to focus at infinity, in other words not directly on to (say) a sensor. So it needs another lens to "accept its output" which seems to be coming from infinity, and focus that onto the sensor.

The non infinite lens is designed to focus at typically 160mm from the lens, so it can go straight to a sensor.

Both are just lenses, and will form an image in either configuration, but noticeably not as well as if they're used as intended.

[pinhole]

Thanks much Johan & ChrisR. Cheers, pinhole

[pinhole]

So, another newbie question.

I'm under the impression a PLAN objective would be considered better for crystallography??? Thanks folks, pinhole

[Pau]

What kind of crystallography do you plan to do?
For photography yes, at least if you want to take single frame (no focus stacked) images. In general Plan objectives are from middle range series and better corrected than no plan ones.
For some very specialized techniques like using Fedorov stage the only available objectives are in most cases not plan corrected and to for the study of some optical properties like the optical sign when you look at the objective focal plane it likely would not matter.

[pinhole]

Howdy there Pau.

Yeah, just single frame imaging of dried solutions, etc.

You've been most helpful, thanks.

Cheers from Wisconsin, pinhole