focal lengths of SLR lenses on DSLR

Hi
I’m about to purchase a DSLR, and part of my decision making will be based on which old lenses I can use.
My old film canon has a 28mm f2.8, a beautiful 50mm f1.2, and a 50 - 250 mm. These are all manual lenses.
My Wife has a newer pentax, that has a 35 -70mm and 70 -210mm and I believe they will all fit on the pentax k200d I have my eye on.

If I buy this 200D body, what focal length will the old lenses be? I’ve searched around and can’t work out what the conversion is.

I loved using my 50mm lens, great quality optics and similar focal length to the human eye (I know it’s more complicated than that) it really suited my photography style. Any suggestions on how I could use this in the future?

thanks from Matt

unless you buy top of the line, chances are your sensor will not be a full frame sensor, and you'll probably get the common 1.6 crop factor...
so basically your 50mm lens will be a 80mm equivalent lens on your DSLR....

the crop factor is usually advertised. just take it and multiply your lens focal by it to get the new equivalent one.

Also, as far as compatibility is concerned, one word: try your lens on the body before you buy.
if you find out that your lens are not compatible, then you can probably widen your search for the body.
I had a sigma that worked on my canon body, but when I moved to DSLR (Canon as well), it wouldn't work. so best try it. if they work, well, it sure is nice to be able to reuse previously bough lenses...

hope this helps..

Thanks that is very helpful.
I can now make sure I dont overlap too much with buying a body/kit.
cheers from Matt

The manual focus Canon lenses will not really work on any Canon EOS cameras whether these are film, full-frame digital, 1.3x crop digital or 1.6x crop.

There are two types of adapters which can be found. The type without optics will not allow the lens to focus to infinity and the type with optics are rare, costly and degrade image quality.

It is really a shame because there are some absolutely excellent Canon Manual Focus Lenses. Your 50mm f/1.2 is a superb lens. In fact the 50mm f/1.8 FD lens provided better IQ than either the EF 50mm f/1.8 Mark-I or Mark-II.

IMO, Canon specifically planned to make the manual focus lenses obsolete so they would sell more auto-focus lenses. It could have been possible to allow the manual focus lenses to mount and operate manually on EOS cameras. I believe that all Pentax lenses will fit on the Pentax family of DSLR cameras.

Added information: It is possible to use other brand manual focus lenses, including some with the old time M-42 mounts on EOS cameras with adapters.