I was asking if the photo showed the proper eye relief. Normally you would see a sharp edge instead of the blurred circle in the photo so the field of view may be wider than it appears in the photo. The description I've read of the periscope use for the rear guns stated that the pilot could steer the guns normally towards the aircraft in the scope because the image was reversed as if in a mirror. This would not be desirable when pointing forward so the image must have reversed when the scope was rotated forward to back.
It seems obvious to me that the guns had to point back along the flight path in order for the periscope to target the bandit instead of being angled down where the bandit is masked by the fuselage.
The image may or may not apply to the PV1B head.
For a fact it was for the RF2C forward & rear view but no PV1B rear view is shown in any of the documents I have.
As far as guns pointing directions are concerned only documents I have all say downwards pointing.
With all the information I now have on the PV1B head they do mention it was designed for rear facing guns.
Yet with all that is there with how to bomb on the forward view there is no mention at all how to sight guns with the rear views.
Even the pilots hand book that I now have makes no mention of rear guns & how to use the PV1B head for shooting.
It only talks about the forward view & the BZA & how to bomb with it.