Went full frame and now my Sigma DC 17-50 f/2.8 isn't compatible.

I just went full frame last week and today getting ready to head out to a shoot and I realized my Sigma DC 17-50 isn't compatible with my 5dmkii. Good thing I still have my old 60D so I can still do the shoot. Is there an adapter I can get or what lens should I replace it with? Thanks!!

I presume you shot at 17mm and discovered image cutoff due to a too-small image circle to cover the 24mm x 36mm frame dimension?
(and not an issue of mechanical interference with the reflex mirror)

There was no interference with the mirror but bad vignette at all lengths.

Did you like the field of view range that the 17-50 gave you? Did you find yourself wishing it were a little bit wider or a little bit longer?

APS-C 17mm = FF 28mm
APS-C 50mm = FF 80mm

So 'same FOV' for FF as 17-50mm on APS-C simply means finding a 28-80mm f/2.8 lens
Better than adding lens elements to 'adjust' FL by introducing more contrast-losing optics into the optical design.

I was happy with the 17-50 but a little wider wouldn't be a problem. I was thinking about trying out the Canon 17-55 f/2.8

ready to snap wrote in post #18662830
I was happy with the 17-50 but a little wider wouldn't be a problem. I was thinking about trying out the Canon 17-55 f/2.8

The Canon 17-55mm is an EFS lens, and will not fit the EF mount of your FF camera, and its smaller image circle will mimic the Sigma 17-55mm on FF!

If you want wider FOV on FF compared to your APS-C 17mm, you want wider than 28mm, the most common FL wider is 24mm.
So you might want to consider Canon 24mm - 70mm f/2.8 lens (but this is a pricey alternative!), or 24-70mm f/2.8 Sigma or Tamron

The 17-55 will not physically mount to the 5D mark II. The 17-55 is only for crop sensor cameras and the 5D series are all full frame cameras.
the 17-50 on a crop sensor is the equivalent to 28-80 on full frame. The best equivalent for your full frame camera will be a 24-70. There are several to choose from and most of them are great. This will get you slightly wider field of view than your 17-50 on the crop sensor.

The Sigma 24-70 DG OD HSM Art should be considered. A bit pricy at $1300 list but the refurb is available at $969. See https://www.sigmaphoto​.com …8-dg-os-hsm-a-refurbished.

ready to snap wrote in post #18662830
I was happy with the 17-50 but a little wider wouldn't be a problem. I was thinking about trying out the Canon 17-55 f/2.8

EF-S lenses are made for crop cameras.

You need an EF lens

Maybe the Canon 24-105 or 24-70 would get you started.

24mm is considerably wider than 28mm on FF body!!!

On APS-C, having 24mm on FF is like using 15mm lens on APS-C

I think the OP has a Sigma 17-50 which has an EF mount. The image circle is designed for a crop sensor and the vignetting will be there. I can mount my Sigma 8-16 on my 5D3 with no mirror interference, but only at 16 mm there is no vignetting

MakisM1 wrote in post #18662974
I think the OP has a Sigma 17-50 which has an EF mount.

EF or EF-S confusing! The best description is that from wiki where it is stated "The Canon EF-S lens mount is a derivative of the EF lens mount created for a subset of Canon digital single-lens reflex cameras with APS-C sized image sensors."

In the Sigma line a DG designation is comparable to EF and the DC designation is comparable to the EF-S. Specifically the OP has the Sigma 17-50mm f/2.8 EX DC OS HSM FLD. Physically it may mount, but for the reasons you outline may yield undesirable artifacts in the final image.

Crop refers to 1.5 or 1.6 (APS-C), not 1.3 (APS-H)
Designations used:

Sigma.....Crop: DC...........Full frame: DG
Canon.....Crop: EF-S.......Full frame: EF
Tamron...Crop: Di-II.........Full frame: Di (and Di-III for mirrorless)
Tokina.....Crop: DX..........Full frame: FX

So a few lenses to consider:

Canon EF 24-70 2.8
Canon EF 24-70 2.8 II
Canon EF 24-70 f4 IS
Canon EF24-105 f4 IS
Canon EF 24-105 f4 IS II

Tamron SP 24-70mm f/2.8 Di VC USD
Tamron SP 24-70mm f/2.8 Di VC USD G2
Tamron SP AF 28-75mm F/2.8 XR Di LD

Sigma 24-70mm f/2.8 DG OS HSM Art
Sigma 24-70mm f/2.8 IF EX DG HSM
Sigma ART 24-105mm F/4 DG OS HSM

Thanks everyone for the informative replies. What budget wise Lens would be a good companion with my 70-200 f/2.8? Most of my work is portrait and I do not mind buying used.