Conclusions and future work

The astronomical potential of Tech Pan and its good response to hypering is well documented in the literature. We have used these data and a series of initially inconclusive in-house experiments to arrive at a process that is convenient, reproducible and safe. Excellent long-exposure Tech Pan sensitivity was attained by a combination of drastically modified hypering procedures, including the use of hydrogen at elevated temperatures, and longer development times. Once it was clear that the hypering processes were successful, significant work was required to modify the plate holders to accept film.

We can now routinely exploit this inexpensive, fine grained, high contrast material to the full, enhancing the capabilities of the UKST (Parker et al. 1999). Particular benefits arise from work on low surface brightness objects (Phillipps and Parker 1993, Schwartzenberg, Phillipps and Parker 1995) and the digital stacking of multi-exposures of the same field, results which compare well with CCDs (Schwartzenberg, Phillipps and Parker 1996). The excellent imaging properties and sensitivity of the optimally hypered product, together with the enhanced sensitivity of the emulsion around H, has led to the new AAO/UKST narrow-band H survey of the Galactic-Plane, Magellanic clouds and selected regions (Parker and Phillipps 1998a, 1998b). This new survey is already leading to many exciting discoveries. Though consistently deep Tech Pan exposures are now routine on the UKST for a variety of passbands including U, V, R, OR and H, the full range of hypering possibilities, including vacuum treatment and baking, have not been explored. Our work shows that D-19 appears to give the best processing results but other developers may prove superior, perhaps with the addition of a fog suppressant. It is not known how well or even if this fine grained material resists the gold spot oxidation deterioration that severely affects many IIIa plates several years after processing. However, in the 6 years since Tech Pan was introduced at the UKST, no films have yet been shown to be affected.

© Copyright Astronomical Society of Australia 1997