I will be on the road tomorrow, so I hope you will permit me to post this a day earlier than normal. The astrophotography bug is biting and so I'm looking to purchase a lens that will perform on the other end of the spectrum from this one and to pay for it I need to move a couple of my better lenses, but this is a beauty. You already know that LOOONG focal length macros are desirable for working distances. (See the prices for the Pentax-A* 200mm macro, as an example). Here is a macro that gives you 1:2 at 180mm (and the freedom to use other focal lengths as well). The "Flat Field" means higher quality in the corners than you are probably used to in ordinary macro lenses.
This is one of the "cult classic" lenses that you rarely find in a Pentax mount. This is a gorgeous copy of this lens and it it ready to use on your Pentax DSLR. My only reason for selling this beauty (and another scarce lens) is to pay for a high-dollar lens that I really need more for astrophotography. The Cult Classics page has this to say about the Vivitar Series 1 90-180mm Flat Field: - - - beginning of quote - - - Vivitar 90-180mm f/4.5 Flat-Field Macro Lens Vivitar also made a number of high quality zooms under the Series I label. The 90mm to 180mm f4.5 flat-field VMC lens from 1978 is an optic that has also achieved cult status . This Vivitar 90-180mm f/4.5 lens was really designed for medical photography needs. A ring-light flash unit was designed to mount on the front of this lens too. But as far as I know, it was never released. This original medical market niche explainssome of the design features and range of this high quality zoom lens. This lens is over 6 inches long, and pretty heavy at 2.3 pounds. At a constant f/4.5, you aren't going to value it for its speed either. But it produces excellent results in macro-work down to 1:4 at 90mm and to 1:2 at its 180mm setting. On most modern zoom lenses, macro photography settings are a lower quality setup. Achieving macro capabilities means shifting some elements and so sacrificing some of the zoom's control over spherical and other aberrations. Most current zooms only offer macro settings at either one end or the other of their range. Generally, you would prefer macrophotography at the longer end of the range, but most zooms opt for the easier macro settings at the shorter end of the zoom's range. Only a few zooms offer continuous macro-settings over their full range. Even the better current zooms generally only get to 1:4 to 1:6 reproduction ratios (.e., the object is one-fourt h lifesize on film). The Vivitar 90-180mm f/4.5 Series I macro zoom is designed to provide the highest possible quality continuously down to its closest macro settings. The Vivitar 90-180mm f/4.5 flat-field lens provides high quality macrophotography continuously from 90mm (to 1:4) to 180mm (to 1:2). That's unique, and useful, so you should expect to pay quite a price premium for such a cult status lens! " - - - end of quote - - - Here is a set of images produced by this same model of lens: http://www.flickr.com/photos/odderikgarcia/sets/72157606482781081/ and here is another thread with images from the Vivitar Series 1 90-180mm Flat Field http://forum.mflenses.com/viewtopic.php?t=17707 This lens is in excellent cosmetic, optical and mechanical condition. I will be happy to ship this lens WORLDWIDE to PDML members. This lens is virtually never seen in a PK mount, so here is your chance to get a Pentaxian's rarity. Priced to sell at $399 plus actual shipping. (See eBay for much higher prices in a much more common mount, and you don't often find eBay sellers willing to ship worldwide). http://www.ebay.com/itm/like/280905685736?lpid=82 Contact me for a shipping quote to your location (serious only, please). (Apologies for the wordiness, but I figured I would just copy and paste what I plan on saying in my Pentax Forums Marketplace ad, to be placed later today. Email me for photos, if interested.) Respectfully, Darren Addy Kearney, Nebraska -- Nothing is sure but death and Pentaxes. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.