I got this lens on Ebay for Minolta / Sony A-mount. The Sigma 500mm F/7.2 APO AF is a 35 years old AF lens. Basically, it is a 400mm f/5.6 with integrated x1.25 teleconverter. You could buy it in the 90s for 500bucks and it really didn't turn heads at the time.
Age is a disease... The stupid Sigma Zen coating was litteraly disintegrating. Had to spend 3 hours removing it, and it's not totally done yet. But it will, and this lens will look quite pretty. The glass is not too bad. There is some dust, no fungus, and likely no balsam separation or foggy element that the naked eye can see. First thing you notice is how compact this lens is. It's smaller than the 135-400 and not very heavy: 1.1kg. Feels nice to walk with a 500mm that is lite. But as we'll see later, it requires a tripod even with the body stabilization, which annihilates the weight advantage.
Anyways, after cleaning, it turned out that lens suffered some extreme  back focus. Even with AF fine tune set to -20 on the A77, there is still a little backfocus. The fact you need to shoot this lens at least at F/11 to get some sharpness helps with that problem: there is a more comfortable depth of field.
Like all Sigma lenses of that era, it suffers some weird spherical and chromatic aberration; color fringing definitely is an issue. It can be somehow mitigated in post.
AF is not bad in good light but it’s better to set the AF motor to slow. On a static contrasted subject it’s OK if you don’t shake… On a tripod (almost mandatory) it’s much better. Manual focusing is not easy: the action is super short, and since it’s old, the mechanism is basically moving freely: if you blow on the focus ring, it will move. When I disassemble it to adjust the internal focusing element to neutralize the back focus and clean the glass, i’ll try to make it more resistant.
This is not a sharp lens at base aperture, and contrast is not great either, especially micro contrast, even if you manually nail focus perfectly. F/11 is the minimum aperture to get acceptable sharpness. It also makes the spherical aberration less of an issue and contrast is greatly improved. It keeps improving until you reach the sensor diffraction limit.
Mounted on the A77 II, 0nly the center AF point is working due to it being an F/7.2 lens. Overall, I’m happy with the images I got from this very inexpensive old lens.F/11 requires a lot of light, and on a long lens you need speed to reduce hand blur. The way to go with this lens is to crank the ISO up (ISO noise isn’t really a problem anymore, blabla blabla I already said that many times). Even with the body stabilization and tripod, you need fix to freeze what you’re likely to shoot with a 500mm that behaves like a 750.
You can judge by yourself with the photos. All were imported in LR, sent to DXO Photolab for basic processing (denoise prime, fine contrast, purple fringing, cropping), sent back in LR for the final processing. A few were also processed in Topaz sharpen AI on a 50% transparent layer (the gulls I shot hand held were soft. The AF struggled). My usual workflow. Nothing fancy or special.
For 89 bucks, it’s a lens you can buy if you occasionally need 500mm and don’t want to spend big money. That is if you can find one with good glass. They aren’t super common, lots of them have fungus or fogged internal elements, and ALL of them have the stupid sticky disintegrating Sigma Zen coating.

You may also like

Tamron SP AF 70-200mm F2.8 Di LD IF Macro
2022
It took me some time to write about that A-mount lens I got NOS for 250 bucks. At that price, you will unlikely find any better F/2.8 telezoom.
Fun with the DXO ONE in 2023
2023
In 2015, Dxo decided to sell a tiny camera that connected to the iPhone. They used the 1inch 20MP sensor from the Sony RX100 m3 that I really love a lot, 32mm equivalent lens that is pretty bright: F/1.8 and shoots RAW.
Nikon N50 / F50 shooting Kodak UltraMax 400
2023
I didn't shoot film for years. Didn't really plan to. Not that I don't like it, because I love film, but I just didn't have an opportunity to do so. When I saw that Nikon F50 with a 35-80 for 20 bucks, I just bought it. Ordered a new battery on amazon and a couple rolls of Kodak Ultramax 400
Shooting the Olympus OM-D E-M1 in 2023, 2024 and later.
2023
One month ago, I was fed up with travelling with camera gear. Air travel became a miserable experience: arguing with check-in people, Unpack all that expensive shit at security, having gear damaged in the plane when frantic fellow passengers trow their hard cases in the overhead bins. I want to travel light: then a classified caught my eye: EM1, grip, charger, 2 batteries and 45-150 for 300.
Shooting the Sony Alpha 77 mk II in 2022
2021
I wrote about the A77. But what about the noticeably more expensive used A77m2? You’ll have to pay $600 to $800 to buy a used one in good condition. Is it worth it? The A77m2 came a few years after the A77. in my opinion, the improvements are mostly marketing stunts. Despite a lot more AF sensors, a so-called new AF system, better video and a bigger buffer, I keep thinking the A77m2 used isn’t a very good deal.
Tokina 12-24 DX adapted on Micro 4/3
2023
Some sample photos taken with the Tokina SD ATX pro 12-24 F/4 IF DX ASP Nikon F-Mount on the Olympus EM1.
Olympus OM-D E-M5
2018
August 2018 I bought that little camera for $150. Definitely a bargain considering it was sold boxed, in a not too bad condition, with less than 6.000 clicks, and included two batteries and charger, a 12-50mm F/3.5-6.3 zoom lens, a 45mm F/1.8 prime lens, the tiny Olympus flash, a couple filters (ND1000 and CPL) and a (slow) 64GB SD card that I just trew away and replaced with a Sandisk Extreme Pro.
Nikkor Plastic 70-300 F/4-5.6 AF-D ED
2023
This Nikkor 70-300 has been one of the most poorly reviewed Nikkor lens ever.
Improving cheap flatbed scans
2023
I still shoot film from time to time, not enough to invest in am excellent neg scanner or bother trying to shoot my negs with a camera. I tried that, don't like it. I love the scanning - editing process.
Shooting the Minolta Maxxum / Dynax 7D in 2022
2019
The short lived most advanced Minolta DSLR was released in late 2004. It became later the foundation for Sony's A-mount cameras. It featured the first in body stabilization in a DSLR, a 6MP CCD sensor and loads of controls. This camera is a photographer's delight. The body feels right, the controls are great and natural: coming from a film SLR, you just feel at home with the Minolta 7D. And You can use all the now often cheap quality Minolta lenses, as well as the more expensive Sony A-Mount lenses.
Back to Top