Whatbird.com

Sorry for lack of content, but reading through a bunch of posts on Birdforum.net, I guess the general trend is that porro prisms in binoculars give roughly equivalent results as roof prisms for lower cost.  Ie, you have to spend more money to get as good an image with roof prisms. 

Does this hold true in people's experience?  I guess the trade-off is bulk and/or weight?

I have had both roofs and porros and I currently use roofs.
Overall I like roofs better but you can get topend porros for around $500 (I can give you the model number if you are interested) - topend roofs are about $1700-2000

Roofs are:

• More expensive
• More durable
• Waterproof and Fogproof (most are)
• Lighter (this makes alot of difference)
  
• Focus easier (in my experience)

Porros are:

• Cheaper for topend
  
• Less durable (if you drop them or are rough with them)
• Not waterproof
• Heavier

I ended up getting Vortex Vipers, which are roofs.

 

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2008 Yard List: 126
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How to Measure magnification
How can I see how strong a magnifying glass is?

I bought this magnifying glass http://www.liangdianup.com/inventory/189901.htm and I want

to know how to test it to see how strong it is. I hear a lot of people talk about

magnifying and how strong the magnification is, but I would like to know the true

magnification of my magnifying glass. I have a few of them and some seem stronger then

others. How can I rate these? How can I pin a correct number on mine? How do the companies

that make these come up with these numbers.