I've been a big fan of particular Tamron "SP" Adaptall-2 lenses for at least a couple decades... esp. 90/2.5 or 2.8 Macro, 300/2.8 IF, 400/4 IF, 180/2.5, 80-200/2.8, and the two mirror lenses 350/5.6 and 500/8. But I don't personally have any experience with or knowledge of the two lenses OP has, or ones others have mentioned. I'm not sure if they would be worth adapting or not. Maybe some more info would help you decide for yourself.
Tamron made (actually still makes) entry-level, mid-grade and pro-grade lenses, same as most lens manufacturers. Tamron is even a major supplier of lenses to Hollywood and the movie industry. In general, the "SP" series are their higheest quality pro grade lenses, some of which might be found relatively cheaply today and may be well worth adapting.
Here's a 90mm f2.5 SP Macro adapted for use on Canon...
There is a Canon EOS Adaptall-2 mount (chipped version) on the lens, and alongside a Nikon AI/AI-S mount is shown. There's a lens hood reversed for storage on the lens, too. One reason I like this lens is that it's compact and tucks into a corner of my camera bag. In fact, I have a couple more copies of the 90mm set up for use in vintage film kits: one with (another) Nikon AI/AI-S mount and another with Konica K/AR mount. You can get Adaptall-2 mounts for practically any SLR/DSLR system.
The mount is easily interchanged. It's essentially another bayonet and there is a little silver lever/button on the side to release the latch. The little aqua paint dot seen in the above photo is aligned with a similar dot on the mount, then it's twisted until it latches (just like mounting most bayonet mount lenses on cameras). The Adaptall-2 mounts - in particular - might have an adjustment for the lens' max aperture, so that the lens "registers" properly on older mechanically-linked cameras. The original Adaptall mount, you had to buy a mount that matched the lens... f2.8 mount for f2.8 lens, for example.
Here's another view of the macro lens, this time mounted on one of my 7Ds...
And, here's a sample image taken with the above lens...
Bee on orange poppy.
Tamron SP 90mm f2.5 lens at f11, with 25mm extension tube.
EOS 7D camera at ISO 400, 1/400 shutter speed. Ambient light, handheld.Not bad for a $60 investment! I picked up the macro lens for all of $20 and it cost me another $40 for an adapter from China (off eBay).
However, it isn't all wine and roses!
First of all - and perhaps obviously - these are
manual-focus-only vintage lenses. Not too big a deal for macro, and probably for some other types of shooting... But some modern DSLRs really aren't very manual focus friendly. Small viewfinders, dimmer viewfinders and focus screens without any sort of manual focus assist features can make it challenging. It can help to get the "chipped" adapters (pretty widely offered for these and most other types of EOS-adaptable lens) so you will be able to use Focus Confirmation. Be aware that only works in One Shot mode, so remember to set it before removing your EF/EF-S lens from the camera.
Focus Confirmation only works up to the camera's limit of focus ability. The center AF point on most Canon is good to at least f5.6, the 1-Series cameras can operate to f8. WIth the third party adapters you can work a little beyond this limitation. It sort of depends upon the situation... Will work better in bright, contrasty situations. Live View might work better (altho slower) than standard AF detection, too.
More importantly, these lenses on EOS cameras are
manual-aperture-only, too. Sorry, but a previous response is incorrect.... You
cannot use Av, Tv, P. You'll have to be using M (or B/Bulb for really long exposures) and manual metering ("stop down" metering method, when using the camera's internal meter... or take readings with a separate light meter).
And you'll need to stop the aperture down manually before taking the shot. This makes it a little slower working with these lenses. Now, when using larger apertures it isn't too big a deal... just set the aperture first, then focus manually. But at smaller apertures, with the lens stopped down your viewfinder will dim and, depending upon how small the aperture, Focus Confirmation can get iffy or stop working entirely, so manual focusing can be more difficult. You might want to select your aperture, but keep the lens wide open during focusing, then stop down afterward, just before taking the shot. Depending upon what you are shooting, that might be fine... or it might be difficult. It's pretty tricky, for example, to capture a moving subject such as a bee flitting from flower to flower, especially at macro magnifications.
Also, in the EXIF you won't see correct info about the lens. The focal length will be incorrect and the actual f-stop you used won't be noted.
So, there is no free lunch... A few things you have to consider if you want to adapt and use those lenses on your modern cameras.
By the way, modern Tamron lenses, some of which are excellent, do not have interchangeable mounts. Now that pretty much all camera manufacturers have gone to electronic camera to lens communication and control, each lens has to be dedicated to the specific mount and it's impractical or impossible to offer interchangeable mounts.
, but i was asking about this lenses because they are just laying there anyway, so i might as well give them a try if it is not to expensive to get this adapter!
but what does that mean?
