Lens Mount Adapter

[jcarstan]

I have an old Takamur 400mm lens used with a Pentax. Screw Mount. Is there an adapter that

will allow me to use lens with a Rebel T3. Realize manual use only. Thanks.

[Waddizzle · Accepted solution]

There are mount adapters available to fit almost every old mount used in the last 40 years to a Canon EOS mount.  The online retailer BHPhotoVideo has a wide selection of adapters, plus online experts to help guide your purchases.

[Waddizzle · Accepted solution]

There are mount adapters available to fit almost every old mount used in the last 40 years to a Canon EOS mount.  The online retailer BHPhotoVideo has a wide selection of adapters, plus online experts to help guide your purchases.

[jcarstan]

Thank you. I'll give them a try. Have had good luck with BH Photo in the past.

[TCampbell · Accepted solution]

Is this "screw mount" actually a T-Mount?

See:  https://en.wikipedia.org/wiki/T-mount

That's a standard which is still used by astro-imagers to mount cameras to telescopes.  If the thread diameter and pitch described in that Wikipedia article matches your lens, then what you need is something called a "T-Ring".

The T-ring has the 42mm x 0.75mm thread pitch on the front side... but a Canon EOS bayonet type connection on the back-side.  It allows the lens to attach to the camera.

Know, however, that when you do this, there are no electronics involved... the camera has idea what lens is attached (it thinks there isn't any lens attached), nor can it read or control f-stops, focus, or anything else.  The lens becomes completely manual and you have to use Manual mode on the camera to control exposure settings.

[ebiggs1]

IMHO. the cold hard facts are it isn't worth spending any money on trying to make it usable on your Rebel T3.

CA and other imperfection like flare control are what one would expect from a 50 year old design.  Way back I had about all the cheap telephoto lenses made.  Fun to play with for sure.  It can be done and it will take pictures.  Some will even be pretty good. Depending on your own evaluation and judgement.

Full manual control is going to be hard to live with.  Manual focusing will be difficult.

[jcarstan]

Thanks for all the input. I know that after living with automatic for so long it will be difficult to get used to all the manual things again. Especially ISO, for me. So, it will be a learning curve and just a fun thing to experiment with. Appreciate all the input.  Jan 

[ebiggs1]

Go for it.  Experience is the best teacher.