Iris

DI-TT-4A on his dedicated tripod

The Iris is a little family of night vision scopes developed and produced in france by Optique et Précision Levallois (O.P.L.) in the 50's for the French navy and army.

The device has at least four variants known so far, all using Gen 0 image intensifier tubes.

It is powered by a removable power supply box plugged into the side of the scope and kept in place by metallic belts. All variants require an external power source to be connected to this power supply. These devices were originally assigned to and used on ships or on land, mounted on a tripod.

The device is supplied with an additional 24V Heymann ES1 oscillator (navy version Iris 2x67 and Iris 4x100) or a 6V oscillator (army version DI-TT-4A), low voltage cables for connecting to the ship's power supply (navy version) or to 6V cadmium nickel batteries (army version), an IR powered collimator who can be plugged into a secondary low voltage output and mounted in front of the scope and 6 spare small lightbulb's for the collimator.

Variants

Iris 2x67

Iris 2x67 and 4x100 power supply front panel

a photo showing the crosshair illuminating directly in the scope , here the device is sideway

a shot taken 7 meter away, here the crosshair have been removed, the observed subject fully civilian black clothes doesnt wear anything on the head or face,the bright horizontal line is a metallic ladder reflecting the IR light

Navy version which uses the BA 56M 24V power supply plugged into the scope. It is fully painted in a light blue color, however at the begining all these devices had a darker blue navy color that has been covered by the lighter colored paint. The optic is a 67mm lens in a seemingly oversized body, as all variants of the 50's use the same chassis.

Iris 4x100

A version of the Iris scope with a bigger 100mm f.1,8 lens giving a 8 degree large vision.

DI-TT-4A

The army version using the same chassis than the others and the same optic than the Iris 4x100, but here it uses a 6V power supply box and conected to a 6V battery by cable. This version is the main part of a whole set deployed by multiple crews that include a 45 centimeter 24V and 250W IR searchlight, a box of batteries and 2 tripods,the DI-TT-4A is easely reconisable by having certaine parts colored in black instead of being fully mono color.

Iris 2x60

the latest member of the Iris family from 1965, it use a diferent more compact and lighter body compared to others Iris scopes , it also adopted a white color instead of the usual blue

Other details

It is believed that all versions from the 50's use the TV.1.A or TV.1.B image intensifier tube, however its only firmly confirmed for the army version.

All version's from the 50's have two anti humidity cartridges inserted in the scope and can be observed trought a round window. Each of them are attached with three screws, the cadridges themself can be unscrewed to be opened for removing the anti humidity sand which can be reused and reinserted in the cartridge after 5 hours at 110°C in the oven, the cartridge is dry when the sand is blue, if the sand is pink/sand colored then the cartridge is humid and needs to be dried out by the manner described above.

All versions do not have any adjustable focus setting, the focus is fixed at 400 meters for the army version of the scope.

The navy version's collimators use a German style reticle, unknown for the army version.

The army version power supply box delivers 15kV, the scope consumes 0.5A, the navy version is believed to deliver between 10 to 12kV and consumes 0.2A.

The scope itself and the power supply box have each their own distinct serial number, having mismatching serial numbers is not to be considered abnormal.

Due to the non adjustable and rather small eye piece compared to modern standards and the rather low light output on the phosphorous screen, its rather dificult to take pictures or video's trought the device, the later parameter may depend of each individual scopes since they are all from the 50's or 60's for the latest version.

It have been observed that lightly illuminated elements or near the limite of visible distance when observed trought the scope appear with a grey color but turn on a more green color when its more strongly illuminated by IR light a phenomene that aparently can be seen irl but hard to capture with camera's, a strange detail that make the Iris one of the only gen 0 device's with such screen colors output.

Warning

For any fortunate owners of the navy version of the device, due to their age it is recommended to power these devices only with 12V instead of 24V to avoiding risks of overheating and damaging the power supply box permanently,indeed the isolant grease used inside the power supply had the time to dry and leave exposed surfaces around the diferent block's of the said power supply.

External links

http://roland.weber4.free.fr/

http://opl.foca.free.fr/viewtopic.php?t=1340&sid=fe1fb6fc0a03d427590fff73250f1d9a

https://www.passionmilitaria.com/t121763-marine-lunette-iris-2x67

http://www.foca-collection.fr/pages_opl/materiels_militaires.html