Field of vision

[mark_h]

I have been slowly building my bench set-up, I call it "Macrodon" This is a 50 shot stack processed in Zerene Pmax. The camera is an olympus E-1 with a 65-116 auto extension set at 65 with an E nikon 10X. My lighting is not finalized waiting for a goose neck illuminator to arrive. I have a Schneider Mount 28mm f/4 COMPONON ENLARGING LENS on the way but not here yet
My question is , is this the widest field of view I can get, I wanted to get the full face. Any suggestion greatly appreciated .

[rjlittlefield]

In your current setup, what is the total distance from sensor to shoulder of mounting threads on the objective? That objective is designed for that distance to be 150 mm, at which point it will yield 10X magnification and a field that covers a 23 x 15 mm sensor with some room to spare. If placed on a shorter extension, it will give less magnification and less coverage, as well as some curvature of field. However I have tested it OK down to 7X on a 23 x 15 mm sensor. Your sensor size is a little bit smaller, so you might be able to get by with even a little bit less than 7X, using a shorter extension.

If you are already running at the shortest extension that will give a good image across your sensor, then about all you can do is stack-and-stitch. That involves shooting two stacks, side by side, and merging them in some photo processing tool, minimally Photoshop or similar, typically a panorama-stitching tool like PTGui or similar. With this subject and lens, you could expect some glitches at the seam, but with careful settings and merging it could look quite good.

--Rik

[mark_h]

thanks Rik I will set the distance at 150 and see how that works.

[rjlittlefield]

Rereading what I wrote, I see some possibility for confusion.

That objective is designed for that distance to be 150 mm, at which point it will yield 10X magnification and a field that covers a 23 x 15 mm sensor with some room to spare. If placed on a shorter extension, it will give less magnification and less coverage, as well as some curvature of field.

"Coverage" in the above is referring to the sensor, not the subject.

To get a wider field at the subject, you need shorter extensions, which will give less magnification. Whatever your current extension is, reducing it will let you see more of the subject.

The catch is that at some point the corners of your image will start to get fuzzy, and beyond that point the fuzziness will just move inward. The objective is built so that it gives a clear image only over a certain angle. When you move the objective too close to the sensor, that angle does not span the entire diagonal of the sensor.

--Rik

[ChrisLilley]

The register distance (sensor to outside of bayonet mount) of the four thirds system is 38.67mm. Adding 65mm extension and a couple of mm for an RMS adapter takes us to around 105mm, substantially shorter than the 150mm for which the Nikon 10x objective was designed.

Using it at 150mm will of course show even less of the fly's head, as the magnification would increase.

It sounds as if a 4x or 5x objective would be more suitable for this subject? Alternatively the Componon 28mm f/4 might be suitable there.

[mark_h]

thanks Chris and Rik I knew I can get more magnification by extending the 65-116 so I will wait for the 28mm to arrive and see how that works.