FS - 7 3/4", fast, swirlie petzval for 8x10, 5x7, 8 1/2 x 6 1/2 This is a Gundlach Manhattan Optical petzval lens, no doubt originally a projection lens. It is one of the swirlier ones I've seen, with a nice rapid dropoff, and nice out of focus highlights. It is also a focal length you don't see every day. Most of these seem to be shorter or a fair bit longer than this. This is an excellent lens for those creative 'out of focus' swirlie type photos. Details: 7 3/4" focal length, approx f3.3. Lens is 3" high with a 2 3/4" barrel diameter, weighs 452g (16 oz). There is another tube that can screw into the rear, about 1 3/4" high and 4oz shown from when this was used for projection. I'll included it since you can use it to vignette the image if you want to do that, especially on a format smaller than 8x10. Comments: The glass is in good shape with the usual cleaning wisps and some dust but nothing to bother your photos. The lenses are marked 'front' and 'back' with the focal length. The two black bands you see are black flocked paper that I put when I use a lens in my universal flange. It helps kill possible light leaks, but you can peel it off if you don't need it. As you can see in the photo of the 8x10 ground glass, there is a rapid falloff of sharpness and a lot of the swirls, even focused at a distance of 50 feet. (The black space under the car on the ground glass is actually the bar across my window...). The next photo shows a smaller part of the ground glass, with the focus around the camper. Very little of the center stays in focus. and the out of focus highlights on the car are practically glowing. Even with whole plate or 5x7, there should plenty of 'bad' coverage to give you swirls away from the point of focus. I popped this on my Wisner 4x5, and even that was starting to get swirlie at the corners at infinity. The rear spacer is homemade but works fine. I tried using the lens without a spacer at all to see if it would increase the swirls, but it seemed about the same to me. I know of one person who is using ONLY the rear elements from a petzval as a meniscus lens and getting interesting results. The traditional way is to use only the front element, but in the rear position. Petzvals can be used a lot of different ways. Price: $165 shipped in the USA from the USA, via USPS priority, insured. I prefer USPS money orders but will take Paypal sent as a gift or if you pay the fees . If sold to Australia, I can take direct deposit. Trades or offers are always considered as well. Yes, I'll ship overseas. You can check your shipping at USPS.com and the rates for a medium flat rate box to your country, including $165 insurance.