I’m trying to pick a DSLR-compatible Canon telephoto lens for wildlife photography in low-light conditions (also, I like doing urban candid photography/street photography from distances, so that too). Naturally, this means high ISO and low f-stop. For some reason, all I can find are like f-4; is that normal? Also, what’s with all the “telephoto” lenses that max out at 200mm? Shouldn’t something like 400mm be better? I suppose I don’t want something too bulky, so 400mm is probably pushing it but idk… if you have experience in this, let me know what you think. I can only seem to find a handful of options, and most are for mirrorless cameras which sucks because I don’t want too many camera bodies so getting ANOTHER one for this purpose would really clutter my shelves as I don’t have any mirrorless Canon’s.
Anyways, budget is tight, nothing north of $1000, let me know what you think!
“Telephoto” has varying meanings from a technical (focal length is longer than actual length) to a “it’s long”, so can be rather meaningless in advertising copy.
Low-light handling is as much to do with the body of the camera as the lens - the lens just gathers light, its the body and its sensor that offers the sensitivity (and you may find mirrorless cameras better at that).
A low-ish aperture number, such as F4, will certainly help in low light but will also add to price and weight by quite a bit (F4 on a 800mm can lead to a silly price!). So, keep it as low as your budget allows for the focal length you want.
The focal length will depend on whether full-body sensor or a crop sensor - if the latter, then 400mm might well be ideal, but for the former, for wildlife such as birds, I’d suggest more like 600mm if you can. If its the local badgers, that’s different.
You might also want to consider zoom - adds to the cost, but adds to options.
Background: I had a lot of pleasure with a Canon R6 + F11 RF600mm (which is something of a budget lens) taking wildlife shots, and often in poorer light (up to ISO2000 or so gets OK shots, and can go much higher for “ID” shots) - I’ve upgraded to a much better (heavier, more expensive…) lens, but that’s outside your budget. The Canon R6 was always billed as good in low light - ironically for having fewer pixels (there’s a trade off).
Given you don’t want RF lens, I’d strongly recommend looking at 2nd hand Canon (or Sigma!) lenses from a reputable source - ideally a competent local camera shop offering a years guarantee on the lens or the like. Don’t just buy from Ebay!!! Many camera enthusiasts have moved to mirrorless (for good reasons, though DSLR still has one or two reasons to use), and Canon therefore cater far more for that market - which means smaller range of new lens, and lots of 2nd hand lens on the market as using EF-RF adapters sucks.