There doesn't seem to be many places about, this place has three versions +3,4,5 but the AC versions are pricey, I think I would want to be putting that sort of money to a dedicated macro lens
http://www.camerafilters.com/pages/closeup.aspx
If that's USD, those prices are whack! I just did a search and came up with this:
http://www.digitalrev.com/en/kenko-filters-224-category.html?match_type=1&page=2
Look at the bottom two rows. Those are typical prices. Not discount cheap prices either... but "typical". Here's what the Japanese site lists:
http://www.kenko-tokina.co.jp/imaging/eq/eq_camera/close/closeup/ac345.html (being the official site they show the actual item too
)
Keep in mind that those are maker prices (MSRP). Discount shops will have them lower. Usually there's a 20% ~ 25% margin.
I also want to thank Tesselator for his excellent instructional guides on macro. All of his contributions were very well presented and contained very useful information. :thumbup::thumbup::thumbup:
NP, <blush>
Now I need to put some of this to practice so I ordered a new Kenko AC No.3 lens for $45 USD including shipping. That's the best price I was able to find. I am anxious to get my hands on it and give it a try.
That's about right.
just wondering is there any gain on putting these on a macro lens for more magnification, say a tamron 90mm with lens element recessed inside?
No.
Hehehe, these close up filters aren't primarily magnifying the scene objects - not very much anyway. They correct for close focusing - mostly. So the numbers correspond to the distance (range) you can focus whatever lens they are placed on. So you would put a #3 or something on a sharp zoom lens that otherwise has a minimum focusing distance (MFD) of 5 feet or something and be able to focus on subjects 9" to 12.9" away at whatever zoom (magnification) you select. Since most "real" macro lenses are already capable of focusing just inches away from the front element you gain very little by using these on a macro lens. There is some increase but it's usually not substantial - or not
nearly as substantial as it would be on a non-macro lens. But, since the AC grade ones detract nothing noticeable in terms of IQ and also attempt to offer a flatter field at the same time, it's certainly worth playing with - especially if you already have both handy.