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                                                                 EXHIBIT 10.51


[LOGO]

                                 January 14, 1999


William L. Grivas, Sr.
c/o Robert S. Brewer, Jr., Esq.
McKenna & Cuneo, L.L.P.
750 B Street, Suite 3300
San Diego, CA 92101

     Re:  Agreement Between Photomatrix Corporation and All Affiliates and 
          William L. Grivas, Sr.

Dear Mr. Grivas:

     This is to confirm and memorialize the agreement by and between 
Photomatrix Corporation, on behalf of itself and any and all of its 
affiliated, related and subsidiary entities (collectively, the "Company"), 
and you (hereinafter, the "parties"), relating to your resignation of any and 
all chairmanships and directorships you have, and leave of absence with 
respect to any and all other capacities, employment, memberships, offices, 
positions and seats you have, with the Company. The parties hereby enter into 
this agreement intending to be bound by each and all of its terms.

     1.  Upon your execution of this agreement, you shall be deemed to have 
tendered, and the Company shall be deemed to have accepted, your 
above-mentioned resignations and leave of absence, with suspension of any and 
all benefits and compensation, except for payment of the Base Salary per the 
Executive Employment Agreement between you and Photomatrix Corporation (the 
"Employment Agreement"), stock options already granted per the Employment 
Agreement, and normal and customary health insurance. Nothing herein shall be 
construed to alter, expand or 


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modify any and all non-competition covenants and agreements and 
confidentiality covenants and agreements between you and the Company which 
shall continue in full force and effect in accordance with their terms. You 
will comply with the Company's written policies of which you have notice and 
which are applicable to all executive and managerial employees. The 
above-mentioned resignations and leave of absence shall be effective 
immediately upon execution of this agreement by the parties, except your 
resignation as a director, which shall be effective upon the nomination and 
acceptance of the nomination(s) to the Board of Directors of the Company of 
either or both Michael J. Genovese and/or David A. Prolman.

     2.  Until the Company's Board of Directors votes otherwise, you agree 
that all communications by you with the Company regarding the Company, its 
business, its customers, its employees and your role (past, present or 
future) with the Company shall be directed by you solely to members of the 
Company's Board of Directors, or such persons as you may be authorized to 
communicate with in accordance with written policy adopted by the Company's 
Board of Directors. Until the Company's Board of Directors votes otherwise, 
you agree to not contact or otherwise communicate with any staff, employee, 
manager, customer, representative or agent of the Company regarding the 
Company, its business, its customers, its employees, or your rule (past, 
present or future) with the Company. You understand and acknowledge that the 
staff, employees, managers, customers, representatives and agents of the 
Company will be directed not to contact or communicate with you regarding the 
Company, its business, its customers, its employees or your role (past, 
present or future) with the Company.

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     3.  By entering into this agreement, neither party shall be deemed to 
have admitted to having engaged in any wrongdoing or actionable conduct. 
Further, the parties mutually understand, acknowledge and agree that by 
entering into this agreement, they are not waiving, relinquishing or 
otherwise withdrawing, nor shall they be deemed to have waived, relinquished 
or otherwise withdrawn, any of their rights, remedies or claims they, or any 
of them, may have, if any, against the other, except you waive, relinquish 
and otherwise withdraw any claim that the Company breached the Employment 
Agreement, provided the Company complies with this agreement. All such 
rights, remedies and/or claims, if any, of the parties shall be fully 
preserved and continue in full force and effect independent of this agreement.

     4.  You acknowledge and agree that in addition to any other remedy that 
may be available to the Company under this or any other agreements with you 
or applicable law, a breach by you of this agreement will excuse the Company, 
upon a vote of the Company's Board of Directors, from the performance of the 
payment or delivery to you of any and all compensation or other forms of 
benefits hereunder.

     5.  The Company acknowledges and agrees that in addition to any other 
remedy that may be available to you under this or any other agreements with 
the Company or applicable law, a breach by the Company of this agreement will 
excuse you from the performance of your agreements and representations 
hereunder, including but not limited to your agreement in Paragraph 3 to 
waive, relinquish and otherwise withdraw any claim that the Company breached 
the Employment Agreement; provided however that no breach by the Company of 
this agreement will affect any non-


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competition covenant or agreement or any confidentiality covenant or 
agreement between you and the Company, which shall continue in full force and 
effect in accordance with their terms.

     6.  All parties to this agreement acknowledge that they have had the 
opportunity to consult with and have consulted with their own independent 
legal counsel regarding this agreement and each of its terms and further 
acknowledge and agree that this agreement was entered into by them freely and 
voluntarily intending to be fully bound by each of its provisions and terms.

     7.  In the event of a dispute regarding the existence of a breach or the 
performance of this agreement by any party, the parties agree that such 
dispute shall be resolved solely and exclusively by binding arbitration in 
accordance with the rules of the American Arbitration Association. Venue 
shall lie exclusively in the County of San Diego, California. The parties 
further agree that reasonable attorneys' fees and costs shall be awarded by 
the arbitrator to the prevailing party in the event of a dispute is submitted 
for resolution to arbitration.

     8.  The parties agree that the terms and conditions of this agreement 
are the result of negotiations between the parties, and that this agreement 
shall not be construed in favor of or against any party hereto by reason of 
the extent to which any party hereto or his or its counsel participated in 
the drafting of this agreement.

     9.  This agreement may not be changed, altered, or modified except in a 
writing signed by the parties. This agreement may not be discharged except by 
performance in accordance with its terms or by a writing signed by the 
parties.


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     10.  This agreement contains the entire agreement between the parties 
relating to the transactions contemplated hereby, and all prior or 
contemporaneous agreements, understandings, representations, and statements, 
whether oral or written, and whether by a party hereto or such party's legal 
counsel are merged herein.

     11.  Each party represents and warrants that in executing this 
agreement, they are not relying on any representations whatsoever, whether 
express or implied, including without limitations, representations of fact or 
opinion, made by or on behalf of any party or their agents, representatives, 
and attorneys, with the exception of the representations set forth in this 
agreement.


                                            PHOTOMATRIX CORPORATION


                                            By: /s/ Patrick W. Moore
                                                -----------------------------
                                            Its:
                                            Dated: January 18, 1999


Accepted and Agreed:

Dated:  January 18, 1999                    /s/ William L. Grivas
                                            ---------------------------------
                                            William L. Grivas

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