IN MY LAST LETTER TO YOU, I SUGGESTED THAT I WOULD TRY TO REVIEW THE STATE OF AFFAIRS ON THE PECO PORTION OF OUR PROJECT.

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP89B00487R000300640034-6
• Release Decision: RIFPUB
• Original Classification: K
• Document Page Count: 4
• Document Creation Date: December 22, 2016
• Document Release Date: August 9, 2011
• Sequence Number: 34
• Publication Date: May 26, 1955
• Content Type: LETTER

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May 26, 1955
In ny last letter to you, I suggested that I would try to review the state of
affairs on the Peco portion of our project.
On Tuesday, May 24, we had a day-long meeting in which all aspects of each project
were discussed. I met with each of the project engineers in turn and brought mV-
self up-to-date as to just where we stood.
I. Rework of 214" Lens. To date we have received 43 Pacific Optical lenses and 40
pairs of filters. We have had an opportunity to check the performance of 26 of
these lenses and 23 of the pairs of filters. The last shipment was received on
May 19, and at the moment is being examined. We have found that all lenses suffer
more or less from inaccurate centering, and have come to the conclusion that the
cells should be reworked to improve this purely mechanical defect. This work is
now underway on a pilot ran. From the optical point of view, under JOB'S direction
we have passed through two stages and are now engaged in a third. JOE provided us
with a new formula calling for the modification of the radii of two of the curves
and a respacing of the various elements. The lens was made incorporating these
changes but showed a disappointingly ama].1 improvement in performance. The second
attempt was the application of an aspheric figure to one of the surfaces in order
to nwuw44 ze the performance on-axis. The rovement was considerable, bbinging
the resolving power from 28 lines/non up to 148 lines/md in the iamediate vicinity
of the center of the field but the change at larger field angles was exceedingly
small. Only the central portion of the surface is employed in producing on-axis
images so we are now at work modifying the outer portions of the lens to improve
the field performance. The results are not yet available from this third rework.
Two-thirds of the red filters examined do not show an appreciable reduction in
resolution at the 50 lines/mm level. The remaining third not be discarded on
the basis of this test. One-third of these filters, but not necessarily the same
individuals,as the one-third above, show some striae. On the yellow filters, 24
examined do show striae but the reduction in resolution is only slight. A
definitive report of all of these tests including the latest shipment of filters
is now in preparation. As soon as this data is accummlzlated, we will ask JOB'S
opinion as to which individuals he would consider acceptable. One question,
however, does face use Since we plan to use the same filters with the new 24"
lens as they gradually replace the reworked 24", we will have to obtain from some
source additional filters as there are not enough acceptable ones in the present
lot. The problem is in the glass and thus rework is not possible. Should we
attempt to obtain additional finished filters for further selection or should we
place an order for glass from which new ones could be made? It is to be borne
in mind that the process of asking the filters which have been supplied to us has
already involved a selection of satisfactory glass from a larger lot.
II. Windows. As I mentioned to you a week or so ago, the tooling for the mann-
ac o the window has been delayed by a strike at the foundry making the
basic casting. Nevertheless, we are proceeding with finishing the first sets by
hand. At the moment of writing, the entire requirement for June has been ground
and polished and is now being edged. The first phase of this project involved
some work on the physical properties of glass in order to establish appropriate
thicknesses. This work has now been completed and a report covering results is
enclosed.
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May 26, 1955
III. New 24" and New 36" Lenses. These lenses utilise two kinds of glass. The
first type,. LaK-9 is now on hand in sufficient quantity to sake two 36" and fifteen
24" lenses. The other type, KzFs-4i we have been notified, is being shipped today
from Germany. Melt data will be supplied to JOB during the early part of next week.
From this he will have to supply us with a definitive optical design before we can
proceed with the actual construction of any lenses. Prototype schedules are quite
close but are still realizable if JGIB can give final formulas very quickly. The
cell designs are complete and have been released for manufacture. Coordination of
these lenses with their various shutters and cameras has been completed so that work
in those areas may proceed.
IV. Inns Test Device. This device has been in operation approximately one month
is going used or the determination of the resolution of the 24" lenses and
their filters. We are extremely pleased with the data which this device is yielding
and a report covering its operation and results is in preparation. We are somewhat
disappointed with the lenses which have been tested by this method since the contrast
capabilities of these lenses have proved to be considerably below what we ocpeeted
based on the normal limiting resolution numbers. As an example, a lens having a
limiting resolution of 25 lines (quite a good lens) turns out to have 50% contrast
at only 8 or 10 lines.
V. Charting Camera. The optical design is complete and many of the glass parts are
well advanced in their fabrication. The film transport mechanism for the prototype
is now in operation and with the samples of film available works extremely well.
After our conversation at Rochester, some careful measurements of the uniformity
motion indicates that satisfactory operation may be expected. The big difference be-
tween the operation of this camera and the sort which we were talking about the
other day is that the camera will work on reasonably carefully handled fresh negative
stock whereas the devices which we were looking at are expected to operate with well-
used positive stock over and over again under a wide variety of conditions as to past
history of the stock. It turns out that the poi ni ma slit openings and actually con-
siderably wider than I had thought and that the real requirement is resolution rather
than uniformity of exposure. These factors added together to give us considerable
assurance that the mechanism as it is now designed will be satisfactory. The project
engineer working on this problem has had considerable experience both with sound on
film projection equipment and with projectors designed for television work. He wasn't
unaware of the problem which was pointed out to us.
The automatic exposure coniz .device has been made up in prototype form and looks very
satisfactory on the bench. The schedule for delivery of the first camera appears
wholly practical.
VI. Periscope. The optical design is complete and glass is now on order. The final
specifications are as follows: The field lens has a 6 3/4" clear aperture, the en-
trance pupil is 34", and with an eye relief of 26" the true field is 38?, the power
0.375 and the exit pupil 2"in diameter. A power changer increasing the power and
reducing the field has been under consideration and at various times was in or out
depending upon the balance of the various advantages and disadvantages. At the moment
the thought is it would be included but there is still some question as to getting it
within the weight limit. Coordination of the mounting and the space requirements for
this periscope have been worked out in considerable detail with Ell. The present cockpit
mock-up includes a model with the specifications described above.
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May 2$, 1955
My recent trip to California turned up the information that the aircraft people
had spent a considerable amount of time in establishing just what they wanted in
the way of a hand control and other knobs and indicators. Among other things, we
have now decided on a reversal of the direction of sensing of the hand control.
This, unfortunately, will require a redesign of a portion of this control, and it
is estimated that a two weeks' delay will result. We have examined the schedule
with some care, and while it may not axu longer be possible to meet the exact dates
shown on some previous pieces of paper, the installation of this device will not
materially suffer in arm case. It was the opinion of all concerned that the change
was worthwhile and should go ahead. We have coordinated the problem of coupling
between the hand control and periscope since this will require some shafting through
already crowded portions of the aircraft but no real difficulties have yet appeared.
We are now building a wooden mock-up of the control panel for installation and ap-
proval.
VII. Cow utor. A report covering the design background on both the periscope and
computer s losed, and although the report covers work carried on some weeks ago,
there has been no significant change in our approach to this problem. Some portions
of the memory unit have been built and placed on life-test. After 30,000 cycles,
equivalent to perhaps 20 missions, no malfunction or significant wear has been un-
covered. The moving pins which form the heart of the memory unit were a source of
concern to us but we have been greatly encouraged by the life-test. A considerable
problem in coordination of the electrical connections involving the computor, the
hand control and the control panel, the recorder and other pieces of electronic
equipment now faces use We have made a small start but I an sure that it will take
a considerable application of effort to straighten out all the details. I an sure
that in the very near future it will be necessary for me to visit BFM for some other
required information.
VIII. Mirrors for "B" and "CO. There is very little new to report here since we
have proceed about as far aswe can go in our preliminary thinking and must await the
delivery of the larger pieces of quartz, which are expected very soon, before con-
tinuing with the fabrication of mirrors.
IX. Configuration C. Our primary need is a more definitive optical design in
order that we may get glass on order and begin to attack the details of the mounting.
Some lay-out and study work is in process and some coordination with the engineers
working on the film transport and reel mechanism has been started but it is not
well-advanced. I have suggested that a quarter scale wooden model be constructed
to simplify the problem of fitting the business together.
I. Test &juipment This aspect of our program is still practically at a standstill
because except for certain standard pieces of equipment, collimators, illuminators,
eyepieces, etc., we are awaiting description from JOB.
GENERAL. By and large I feel that all is going pretty well. We have not encountered
arr serious breaks in schedule or any technical problems of a sort which lead to
difficulty. It is possible that the first periscope will be delayed because of the
hand control but otherwise I am very encouraged. One area in which I an becoming
apprehensive is the extremely heavy load which is building up for JGB.within the
next month. We expect him to complete the rework data on the 24" within the next
week or no. Our schedule calls for the delivery of a definitive design on the 24"
and 36" for Configuration B. within just a few days of our delivery of the melt data
to him. We are still pressing for preliminary design data on "C" and the optical
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test equipment of the special nature is still before us.
I hope this report will serve to bring you up-to-date with our progress.
RMS/dmg
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