Author Topic: Canon FD 1.8/50mm SC on a Nikon DSLR question  (Read 1123 times)

paul_k

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Canon FD 1.8/50mm SC on a Nikon DSLR question
« on: August 08, 2017, 02:05:43 »
Although I'm nowadays fully committed to Nikon (nothing ideological, simply can't afford/won't invest in two separate. in particular digital, camera systems) way back when I took my first steps in photography the first 'serious' camera I had (2nd hand, bought it from my older brother who switched to an Olympus OM-1) was a Canon FTQL together with several Canon FL mount lenses, in particular a FL 1,8/85mm.
Despite not being as rare as the FL 1.2/58mm, it in its days still  was pretty exotic and expensive. Loved that lens, took a few pictures with it which I after nearly 45 years still look back at fondly

When I later started my photography studies, switched to Nikon, and after some time gave away my Canon set to a girlfriend.
Kept the 85mm though, with the idea maybe someday finding use for it again
A couple of years ago got a FD mount Canon TX (with a FD 1.8 50mm SC) just for fun (don't shoot film seriously anymore), on which I knew the FL 85mm could nevertheless be mounted, and even have TTL metering (even if only stopped down)

Fast forward to nowadays
Recently found a Canon FD to Nikon F adapter (with glass element), quite inexpensive  at just US 18.50 (incl shipping costs from China to the Netherlands) Considering my TX accepts a FL mount lenses, I hoped the adapter would too. So took the risk and ordered one.
Delivery was surprisingly fast, already received it within one and a half week after purchase.

Well, the adapter (which BTW is non AI) doesn't accept FL lenses, due to the aperture guidance pin on those lenses sticking out too far (FD lenses have a different construction in that respect).
Fortunately I still have the FD 50mm, which with the adapter becomes a more or less 70mm.
The max aperture is a bit unclear, since the manufacturer did not mention the amount of magnification. and I consequently can't exactly calculate the exposure extension factor of the adapter. Not a biggie though as that is taken into account when using TTL metering.

Did run into another more interesting/intriguing phenomenon though.
When I use the 50mm (with adapter) wide open on my DF, the images are really soft and, apart from somewhat OoF, also seem somewhat back focused. Obviously my first thought was this was an inevitable consequence of the low quality I could only expect from such a low priced adapter.

But to my amazement, I found that when I close down the lens as little as one stop (and a bit) from 1.8 to 2.8, any possible back focusing disappears, while sharpness and contrast improve dramatically, becoming nearly as good as on my 1971 Auto Nikon 1.8 85mm H at 2.8 (don't consider it fair or realistic to compare a 1971 FD lens with a modern AF 85mm)

So my question is:
Has anybody else have experiences regarding sharpness and contrast with the Canon FD 1.8 50mm SC (in particular used wide or nearly wide open) to share, and perhaps has also used that lens with an adapter on a digital camera (Nikon DSLR would be nice, but I understand many old FD lenses end up, just like many old manual Nikon lenses, on mirror less bodies)

Thanks in advance

Akira

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Re: Canon FD 1.8/50mm SC on a Nikon DSLR question
« Reply #1 on: August 08, 2017, 04:19:38 »
Frankly speaking, you can't really except anything good in terms of the image quality from a mount adapter with the auxiliary lens, compared to the dedicated teleconverters that are made from several optical elements (some of them are even aspherical or made of ED glass).

I have an M42 to Nikon F adapter with the same lens, but I bought it for a different purpose (to mount M42 helicoids to use with enlarger lenses) and didn't even tried it with an M42 lens.

As you would already know, the auxiliary lens functions as a teleconverter made of a single element whose performance wouldn't be that stellar.  So, I wouldn't be surprised if the image quality suffers because of the back focus or the residual spherical aberration or whatever with the attached lens wide open.  With the lens stopping down, the IQ would improve as expected.
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