Need adapter tokina 100-400 f/4.5 minolta to Canon Digital SLR

None directly. The T90 was the last Canon camera to use the older FD lenses. All newer Canon SLRs, film and digital, use the EF mount. However, by using an adapter such as http://www.rakuten.com/prod/adorama-canon-fd-lens-to-eos-body-adapter-with-correction-glass/216466533.html?listingId=120668308, you can use the old lenses on any Canon digital SLR.

Here is an article describing the process and giving some links to the necessary adapter.

Quantary makes lenses for a variety of cameras. A lens for a Minolta, for example, will not fit onto a Canon. Assuming you get the lens with a Canon EF mount, then yes, it is compatible with a Canon digital SLR.

Minolta had two lens mounts. One for manual focus SLR film cameras and one for Auto Focus SLR Maxxum film and digital SLR cameras. Sony uses Minolta Maxxum lens mount.
If the Sigma 400 f5.6 lens was made for Minolta X-700 series, XG, series, XD series, SRT series, then it will not fit on your camera.

Believe it or not Minolta Maxxum 7000 had a optional digital back but the resolution was very low. I think it was something like 640 by 480 pixels.
http://tinyurl.com/25hshb4

Montgomery Ward branded lenses were rebadged Cosina lenses supplied by Sears. As such they are virtually unknown outside of North America (and almost forgotten in their home market).

Cosina were a well known budget lens manufacturer and supplied their products with mountings for most major brands including Minolta.

Your lens can certainly fit your camera with a suitable adapter but how functional and useful it is depends upon what mount the lens already has. Due to different body depths used by competing SLR brands it will either work reasonably well or will be unable to achieve infinity focus. Canon SLR bodies were the shallowest and could accept adapters without difficulty for all other 35mm SLR brands but conversely this meant that Canon lenses with adapters could not achieve infinity on other makes. Olympus were in completely the opposite situation as they had the deepest bodies. Minolta were somewhere between the two extremes.

There were plenty of lenses for all of the major brands and an excellent supply of third party suppliers such as Cosina, as a result there was rarely any need to fit brand A to brand B and adapters were rarely produced and were generally expensive.

Minolta were one of the first manufacturers to change their mounting to an autofocus system in the 1980's so any adapters which were available have long ceased to be available and would even be difficult to find at used camera fairs.

You would be far better to look at the mounting ring of your Monty to see if there is an indication of which bayonet mount it has: K=Pentax, N/Ni=Nikon, Om=Olympus, C/Ca=Canon, CY= Contax/Yashica, MD=Minolta. There are plenty of others but these are the most common bayonet mounts, if you cannot identify the mount try taking the lens to an older hand at a traditional camera shop to ask if they recognise it. Using this information you can then sell your lens and use the funds to buy one which fits properly.

Montgomery Ward are virtually unknown to most 35mm SLR users so it's near impossible to sell and even then will be near worthless, but if you mention that it's a rebadged Cosina you increase the chances of a sale as folks will know what they're buying. Cosinas do not fetch much but at least they will attract buyers. The exception to all this is if the Monty has an X mount: this would mean it's a Fujica mount and Fujica owners were always starved of lens options. As a result X mount lenses will often fetch prices well in excess of double what would usually be achieved, particularly if there are competing buyers and if it's a particularly desirable focal length lens.

Although the Monty won't fetch much, you can also expect to pay peanuts for a replacement unless it's a genuine Minolta model and in any case will very likely have spent less than you would were you to actually find the correct adapter on sale.

I hope that you have found my posting to be of use and ask only that you return the favour by rating my answer.

As I understand it, Sony bought Minolta, lock, stock, and barrel. Theoretically the lenses should fit and may work on manual, but I'm very sure they will not totally work on sony digital cameras. I wouldn't even try to fit them as the autofocus system on the camera may be damaged.

http://shop.ebay.com/items/_W0QQ_nkwZminoltaQ20canonQ20
adapterQQ_armrsZ1QQ_fromZR40QQ_mdoZ

here is a link to an ebay search for minolta to canon eos adapter, they sell for just about every camera. i know it sucks, buying a new camera that wont work with your favorite lens, but i think you might be better served focusing (couldnt help myself) on camera features and pricing. i own a canon dslr and love it. sigma has a cool dslr. it has a three layer image sensor, with a removable on sensor ir filter. the ir filter thing is really cool.

Sorry, the mounts of Minolta manual focus lenses are different than their auto focus series. Sigma, Tokina and Tamron all make compatible zoom lenses to fit the Maxxum series cameras

A: Your local (specialist) camera shop should be able to look at that for you. But it could be that nothing is wrong and you would be wasting your time because:

B: Searching through other forums, it seems that Tokina's official stance is that it is not designed for digital cameras. eg www.dyxum.com/reviews/lenses/reviews.asp?IDLens=182