Ricoh GXR: A12 Converter Experiments

Introduction | A12-28 | A12-50 | Conclusions | Forum Discussions

Archive

This page presents the results of some experiments that I did with the S10 converters (TC-1, DW-6) on the A12 camera units, compared with the units without converter. On a second page, I change aperture for some constellations for a more differentiated picture.

Note: See also Pavel Kudrys' A12-28 converter experiments: GXR A12-28mm + extension lenses (DW6, GW2, GT1, TC1)

Introduction

Already in spring 2010, I did some tests with the A12-50 module and the two S10 converters TC-1 and DW-6 holding the converters with my hand in front of the lens. Neither of the converters seemed to work successfully, but there was still some uncertainty become the shots were hand-held. Since November, I did some more hand-held tests, which included the new A12-28. Again, the results were not really encouraging. After Pavel Kudrys has published his converter experiments on his Ricohforum, I decided to buy a step-up ring (40.5 to 43 mm) and perform some real and final tests. Here and on page A12 Converter Experiments (2) are my results.

	Focal Length	DW-6 (0.79x)	TC-1 (1.88x)
A12-28	28 mm	22.1 mm	52.6 mm
A12-50	50 mm	39.5 mm	94 mm

Table: Overview of obtainable focal lengths (equivalent)

The table above demonstrates that for the A12-28 module only the DW-6 is interesting; it would provide a more extreme wide-angle lens. For the A12-50 module, both converters would provide interesting options. However, a A12-28 with DW-6 attached is far from a pancake lens with the same focal length and thus not that interesting.

A12-28 with and without Converters

I tested two motifs with the converters at the A12-28 module.

Test Samples

Click the images for original samples. Originals are reduced to 50% in order to save server space.

A12-28 + DW-6, 22.1 mm

A12-28, 28 mm

A12-28 + TC-1, 52.6 mm

A12-50 Module with and without Converters

Again, I tested two motifs with the converters at the A12-50 module.

Test Samples

Click the images for original samples. Originals are reduced to 50% in order to save server space.

A12-50 + DW-6, 39.5 mm

A12-50, 50 mm

A12-50 + TC-1, 94 mm

Conclusions

A12-28

Wide: The DW-6 might be usable and provide a useful extension at the wide angle range for the A12-28 module, but overall sharpness and, much more so, corner sharpness is not satisfactory. My results look even worse than those of Pavel Kudrys.

Tele: The TC-1 does not make any sense on the A12-28 module, because nearly the same focal length can be achieved using the A12-50 module at a much higher quality. Although sharpness is OK, vignetting is too strong to make it a viable option.

A12-50

Wide: The DW-6 might provide a useful extension for the A12-40 module, delivering a heavy-weight 40 mm non-pancake lens combination, but the sharpness is not satisfactory at all.

Tele: The TC-1 delivers a nice "smearing effect" at the A12-50 module - so it might spare you buying lens baby...

Forum Discussions

I will post my results in the dpreview Ricoh forum.

In addition, Pavel Kudrys did some A12-28 converter experiments and documented them on his Ricohforum Website: GXR A12-28mm + extension lenses (DW6, GW2, GT1, TC1).