In order to help satisfy your Gear Acquisition Syndrome, I'm offering my Sigma 8mm f/3.5 in the Nikon F mount for sale. This is a FX-format lens designed to project a 180° CIRCULAR image on an FX body. The sides and corners of the images will be black. Mint condition. I use this lens to create 360x180 VR images. Glass is clean in both front and rear. This is the CURRENT version of this lens. If you research prices, DO NOT confuse this with the older model! Original slip hood, front & rear saps and nylon case are included. This lens will work on both FX and DX bodies, but will not give you a full 180° circle on a DX body. Also be aware that there is no motor in this lens, so it will not autofocus on entry-level bodies.... you will need a focus motor in the body to autofocus. This is rarely a problem as the DOF is so deep using hyperfocal distance, that you can just set the lens focus ring manually to 3 feet, set the aperture to f/8 and fire away. The ONLY reason I'm selling this is I'm selling both my 15mm and 8mm fisheyes to fund the purchase of the new Nikon 8-15mm. I've raced the Siggmas against the Nikkor and the IQ of all three is a photo-finish (no pun intended). So I'm selling the Siggies and getting the Nikkor simply to reduce bulk and weight. This lens sells new for $899 and given that this one is 99.99999% as good as a new one, I'm asking $600. I'll even take the hit on the PayPal fees. Plus I'll pay for CONUS shipping.... outside the lower 48 I'll need a bit more so contact me for the amount if you're interested. Act fast, and I'll sell BOTH the 8mm and the 15mm fisheye I also have for sale for $950 for the pair. You can check my feedback here on the forum, as well as ebay (I have the same username there).