k 35 lenses

rob spence · August 3, 2007

Hi

If anyone is buying any K35 lenses on ebay or wherever please make sure that they haven't got yellowed ( and therefore unusable ) glass. I bought some recently which were yellowed and managed to return them and get the money back, but they may be out there for sale again...so please beware

cheers

rob spence

Stephen Williams · August 3, 2007

Hi
If anyone is buying any K35 lenses on ebay or wherever please make sure that they haven't got yellowed ( and therefore unusable ) glass. I bought some recently which were yellowed and managed to return them and get the money back, but they may be out there for sale again...so please beware

cheers

rob spence

Hi Rob,

Many older lenses are 'yellow' it's due to radioactive decay. I often shoot with 'yellow' glass, it's no big deal and you dont need an 85 filter with some bad examples such as a Cooke SII 75mm.

Stephen

Nate Downes · August 3, 2007

I rather like some yellow lenses...

rob spence · August 3, 2007

Hi Stephen,

they were very yellow...rather like looking through a coral filter. I love k35 and would love to buy some ... but surely they must colour the image when they are this yellow?

best

rob spence

Stephen Williams · August 3, 2007

Hi Stephen,
they were very yellow...rather like looking through a coral filter. I love k35 and would love to buy some ... but surely they must colour the image when they are this yellow?

best

rob spence

Hi Rob,

Probably worth doing a film test if you were worried, sounds like the colour of some Cooke SII's I've used. I have some Nikon Stills glass 35mm & 50mm f1.4's that look kind of coral. With digital grading such errors are easy to fix.

Stephen

Hal Smith · August 10, 2007

Many older lenses are 'yellow' it's due to radioactive decay. I often shoot with 'yellow' glass, it's no big deal and you dont need an 85 filter with some bad examples such as a Cooke SII 75mm.

No kidding, my recently calibrated Minolta Color Meter II says my 75mm SII is almost exactly an 85, it looks more chocolate/orange than yellow to the eye. Has anyone ever seen a proper autopsy of radioactive decay colored lenses? Is it all the elements, reversible by some process, etc?

Stephen Williams · August 10, 2007

No kidding, my recently calibrated Minolta Color Meter II says my 75mm SII is almost exactly an 85, it looks more chocolate/orange than yellow to the eye.

Hi Hal,

I am sure many people reading my post thought I was joking!

Stephen

chuck colburn · August 10, 2007

For some reason I remember the yellow look of the glass in the K35 lenses was due to the type of lens coating. But it's been awhile.

Hal Smith · August 11, 2007

I am sure many people reading my post thought I was joking!

Geoff Boyle wants everyone who has a set of those obviously inferior old SII/III's to put them through a crusher so he'd be the only one left with a set.

Stephen Williams · August 11, 2007

Geoff Boyle wants everyone who has a set of those obviously inferior old SII/III's to put them through a crusher so he'd be the only one left with a set.

Hi Hal,

Geoff Boyle sold his set to a CML member who had his cameras & lenses stolen. I understand they were rather expensive!

Stephen

rob spence · August 12, 2007

Hi Chuck,

the coatings on the K35s are yellow...but thats not the same as the glass being discoloured yellow.

My 85mm example is perfectly clear when you look through it, and has yellow coatings.

Does anyone know if it is only the 35mm and 50mm lenses that are affected?

best

rob spence

Hal Smith · August 12, 2007

Geoff Boyle sold his set to a CML member who had his cameras & lenses stolen. I understand they were rather expensive!

Were Geoff's lenses rehoused? If so, they would have been expensive, VERY expensive!

I've managed to put my Arri standard mount set together one lens at a time for relatively little money and have gotten pretty decent lenses so far. An incredible bargain was a mint 25mm SPIII that someone had pulled the focus stop to get in closer and as a result had jammed it. I got it for $250 and Guy at ZGC was able to fix and collimate it for their minimum charge - that was a deal! I've sent all my lenses to Guy for checking and collimation, I may not have a matched set but at least they've all been checked and collimated by the same factory service representative here in the US.

I'm buying a 50mm SPII Monday so the only one I won't have in SPIII/III's is the 32mm. I've also been looking somewhat for the longer Cooke lenses like the 100mm Deep Field but they've gotten pretty rare at the prices I'm willing to pay. The last 100mm I saw for sale was with a Nikon converter and was going for around $1200US.

Stephen Williams · August 12, 2007

Were Geoff's lenses rehoused? If so, they would have been expensive, VERY expensive!

Hi Hal,

They were rehoused by Van Diemen who charged approx £4500 ($9000 in todays currency) per lens to convert them. I understand that Geoff made a profit.! The set that was stolen were Century conversions.

The sets never really 'matched' in todays terms, they can vary quite a bit lens to lens. I know Van Diemen often took elements from several lenses to make a really good one, I guess the less good elements got reassembled and ended up on EBay :(

Stephen

Robert Hughes · August 13, 2007

Sometimes the yellowing in old lenses is not from radioactive decay but from aging of the Canadian Balsam used in cementing lens elements. Ive heard that the cement yellowing can be lessened by exposing the wide-open lenses to direct strong sunlight for an afternoon to bleach out the cement. Be careful not to let the lens overheat, or have anything directly behind the lens that might burn or melt, because a camera lens works just like a magnifying glass, roasting ants and lighting firecracker fuses like we did in our youth.