Quote:
Originally Posted by Duniac
This will be my second photographed lunar eclipse. I have the opportunity to use a Canon EF 500mm f4.0 on my Canon 7d, with the crop factor this will be the equivalent of 800mm. I don't think this will be a problem as I have a very solid tripod.
Should I also use a Canon 1.4x extender on this lens? This would produce an equivalent focal length of 1120mm, however I would loose an f-stop. So my question is, would this be a better setup to use the extender?
Thanks in advance for your assistance.
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If you understand this already please ignore. Just seen a lot of people get caught in this myth.
Crop factor magnification is a furphy. It's an illusion. Nothing can increase the focal length of a lens.
What crop does is actually reduce the FOV of your lens compared with fullframe.
So you are actually getting less use of your EF lens.
It's what some less reputable camera people use to sell crop frame cameras.
example
http://digital-photography-school.co...rop-factor.jpg
RE the 1.4 tele. Go for it. Before getting my telescope I used my 100-400 + 1.4 tele on manfrotto tripod. Remember you'll want shutter up around 1/1000th or better. Which will mean ISO800 +
Is the lens IS?