Evaluation of the mirror's figure and optical surface. Cost $75

The cost of evaluation is included in the refiguring price if you decide to have me refigure the mirror.




Annealing:
Between $75 and $225 depending on size. Shipping to the annealer is extra.

Retouching the figure:
Cost variable depending on how much is needed.

Refiguring:

 

 

 

 

 

 

 


Scheduling your mirror for refiguring.

Evaluation:

Upon receipt of your mirror I will perform the following tests:

  • Foucault test in two axis
  • Ronchi test for assessment of surface roughness/"dog biscuit" and for gross zonal errors
  • Photograph of the surface at the 70% zone to document surface quality for comparison purposes.
  • If you decide to go ahead with refiguring the mirror I will strip the coating, evaluate the anneal and the physical surface for completeness of polish, pits etc.
A good anneal is essential for a high quality mirror. In order to ensure a clean figure of revolution and longevity of the figure the anneal needs to be good or above. Annealing is at the customer's discretion.


Retouching is in order when the mirror is smoothly surfaced, has minimal zonal and/or spherical aberration, no significant astigmatism, and no turned edge.

Refiguring:

The cost of a full refigure includes regrinding the back of the mirror blank (if not previously ground), full 12 hour polish, figuring, coating and shipping. I will recommend a full refigure if I find an incomplete polish which requires polishing to a sphere at the least. The $75 evaluation fee is included in the prices below.

Aperture below f/5 f/5 and above *
10"

$690

$590

12.5"

 $870 $725
14.5" $1250 $950


* Maximum focal length of 84" for all mirror sizes.

Because a mirror destined for refiguring is frequently of a different focal length than other mirrors that are in process in the shop, the mirror must be processed in between longer runs of mirrors. It is best to send your mirror in at a time when I will have a break in the schedule and can tackle the refiguring job in a timely manner for you. I know how frustrating it can be to have a scope without a mirror.

In order to make the turn-around time for refiguring your mirror as short as possible I have started a list of those who are planning to have their mirror refigured by Stevens Optical. When your mirror comes up in the schedule I will contact you with instructions for shipping. The mirror will leave my shop within one month of receipt of the mirror unless it is decided the mirror needs annealing. A mirror that needs annealing will need an additional four to six weeks for shipping and processing by the annealing company after which I will be able to start the refiguring process.

I ask that you make a commitment for refiguring your mirror by placeing a non-refundable deposit of $50 with me. A deposit of $50 will ensure a confirmed place on the refiguring schedule and is applied toward the cost of the refigure.