This is a 500mm f8 Photax lens originally designed to mount on SLR cameras (35mm and smaller formats) using a T-mount converter. Focusing is manual (from infinity down to about 40 ft. if the lens is used without additional extension), aperture control is manual using the preset ring method. On a 35mm body this is a very long lens - on a digital camera with APS-C or smaller sensor it is an extreme telephoto, very useful for wildlife photography etc.

It's in average optical, mechanical and cosmetic condition and would benefit from a full clean and service. There is slight internal fibrous dust in the front element which may be an early sign of fungus. The rear element has slight whitening which is caused by oxidation of the glass, a common problem with these long lenses which may reduce contrast slightly. There are minor marks and scuffs on the front glass but nothing that will cause problems. The lens barrel has some scuffs and scratches.

I'm selling it with front and rear caps, a skylight filter, a nylon bag (originally intended for a tripod; not padded) and an M42 screw T-mount - if you would prefer a different mount please check with me, I have a few others (but may not have rear caps for some of them). I don't have any mounts for mirrorless cameras.

I took test pictures using a Sony A3500 with M42 adapter. All pictures were taken at f11, 800 ISO. Weather was overcast for all pictures. Some marks visible on the final picture are dust on the sensor, not a problem with the lens.

Church 230 yards - 1/640th f11

Tree 30 yards - 1/320th f11

Bird bath 17 yards - 1/125th f11
Aircraft, 1-2 miles - 1/4000th f11
These lenses were sold under many different names from the 1970s onward - Photax and Paragon were a badge name used by Dixons, one of the British importers, not the manufacturer, and nobody seems to be entirely sure who actually made them. There are reviews here:
https://www.pentaxforums.com/userreviews/quantaray-500mm-f8-f32.html
Warning - I wrote the most recent review on this page eight years ago, when I had a very similar Dufay-branded lens. This is the model with 72mm diameter front element.

As usual I'm starting low and with no reserve. I'm separately selling some other photographic items. If you buy multiple auction items from me please request a combined postage invoice (UK ONLY), I'll do my best to get it down to the lowest possible price. Due to its length it must be sent as a medium parcel, postage is priced accordingly. Postal prices recently rose.

International buyers: Due to this item's size I am only able to send it via eBay's global shipping service. Please note that eBay sets the price for this, not me, and that additional items cannot be included when this service is used. eBay will add VAT or sales tax to the price in some countries.