LENS REHOUSING GEAR
recementing – needs doing. Assuming they are happy with the condition for rehousing, it’s full steam ahead. Next, explains Lowe, the lens gets fully disassembled. The optics and iris (if it doesn’t need replacing) are meticulously cleaned, before getting loaded into new metalwork. After that, the lens will be built up to a stage where you can set the back focus and check and align the image. “Once we’re happy the image is as expected and within specification, there’s a final clean and full assembly with all the blank sleeves on,” continues Lowe. “We then set the back focus again, take the lens into the projection room and mark up the focus scale individually, so each mark on every focus scale is done individually. The iris is done on the T-scale bench to make sure we get accurate aperture readings.” TLS will then remove and engrave sleeves, build the lens back up into its final form and give it back to the technician, who completes a last check and ensures the whole set matches and ARTISANAL TOUCH The rehousing process can throw up challenges, but they're usually surmountable in expert hands
feels consistent, before a final QC. Once it gets the stamp of approval, it’s time for the newly revitalised lens or lenses to be shipped out to the customer.
for. If they still want to go ahead? “We’ll give feedback, let them know the faults with the lens, then advise them on the work,” says Whitehurst. “Sometimes, a lens needs replacing. If a client still wants that lens rehousing, as long as we think we can mark it up, we’ll be clear about the limitations and do it if they want to.” GLASS ACT Another point in the pros column for rehousing is the simplicity of maintaining them, claims Leach. “Servicing an old lens which has been rehoused can be much easier than servicing the original lens because the mechanisms in modern housings are usually simpler in design. Present-day designs employ advanced machining capabilities as well as modern materials, enhancing simplicity and ease of maintenance. These improvements will also boost durability – extending their life and usability. “Many old lens housings are damaged by years of use, servicing and people using the wrong tools, making them hard to dismantle,” continues Leach. “Additionally, since many old housings are worn out – leading to problems like backlash and alignment issues – they
WHEN CAN’T YOU REHOUSE A LENS?
The process can throw up issues; Leach points to intricate designs that are tricky to disassemble and reassemble as well as the availability of parts – both of which are surmountable in capable hands. Meanwhile, Whitehurst says floating elements (where there are one or more groups of elements moving at a different rate to one another) present hurdles in ensuring everything is correctly aligned. To tackle this, TLS uses a variable cam system which allows for fine adjustments – a feature not universally employed by other rehousing companies. But are there situations where rehousing is simply not possible? “If you have enough money and can find someone willing with the time, then any lens can be rehoused!” assures Leach. TLS cautions, however, that occasionally a lens is so badly damaged – or has a fungus problem so severe – that a client might not get the result they are hoping
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