Where you buy this lenses for HD cameras? Do you have some inexpensive source? Century Optics lenses are too expensive.

I have Sony FX1E camera. I need high quality CU lens but want to save money.

How far must be adapter from the camera lens? Is there ideal distance?

http://www.optosigma.com/miva/merchant.mv?Screen=PROD&Store_Code=OS&Product_Code=pg49-52&Category_Code=Achromatic+Doublets

These achromats appear cheaper than Century Optics. 100-120 USD for 51 mm lens. They say they have larger sizes too. These may good for FX1. Did anyone check the price on 72 mm lens? Is 72 mm needed?

How you determine what diopter they are? There is some formula.

Also could you use these as condenser lens?

Where you get metal frame that goes around it?

I found out how figure out diopter of lens. Just devide 1000 by focal length (in mm) of lens.

That means Opto Sigma achromats rated from 1 to 12 diopters.