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Forum: Pentax Lens Articles
01-19-2009, 06:18 PM
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Sorry Stewart i probably should have taken a wide angle shot of the room... there are 2 windows separated by a little bit of wall, one was positioned to the rear to cause backlighting and the other out of the frame and closer to the foreground for a lot of side light about 45 degrees off the line of the lens
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Forum: Pentax Lens Articles
01-19-2009, 02:44 PM
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I agree, there is no point it getting rid of your current hoods, they may be adequate in the cases of DA primes or they may be useful on other lenses, they can also be what you transform into a longer hood... and the reality is that this seems to affect the lenses with bad contrast the most, many lenses are pretty decent with the hood provided
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Forum: Pentax Lens Articles
01-19-2009, 02:05 PM
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Great point RBellavance, also the Nikon 14-24mm F2.8 has a stationary hood
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Forum: Pentax Lens Articles
01-19-2009, 12:49 PM
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I have often said that i hate my FA50mm F1.4, sure its a sharp lens at F4.0, some say even at F2.8 but when i want the speed the sharpness
just isn't there, in fact the only fast lens i have that doesn't really suffer a lot from low sharpness wide open is my FA35mm F2.0...
In the case of the FA50, its all about low contrast, same goes for the F50 F1.7 and Sigma 24mm F1.8... and a little bit on the FA77mm F1.8 Ltd...
I know a hood is important for getting rid of stray unwanted light, but you really never no how important it is until you have a bad case of low
contrast for a given lens and you try a lens hood on it. in a personal review of the Sigma 24mm F1.8 someone wrote online they made a really
interesting point, The film (FF) lenses come with a hood that blocks stray light for the FOV related to full frame, however on a crop sensor the
hood needs to be 1.5 times longer to get the greatest benefit, he said he used his Sigma 70-200 F2.8 hood on his 24mm F1.8 without vignetting
and with far better contrast... the other thing we all should understand is that zoom lenses hoods are only good for the widest FOV...
with this in mind i picked up a lens hood off ebay said to be good for 37-90mm ore something like that, its a 49mm thread and its about 37mm
long and 60mm in diameter (it came with a 58mm lens hood)... the hood is longer then the built in hood of the 77Ltd too by about 1.3 times.
here are some of my conclusive test to confirm how much a lens hood helps
Testing back light glare 50mm F1.4 @ F1.4, F2.0, F2.8
what the test looked like
100% crops description written on photo
You can clearly see a marked improvement in contrast and overall sharpness
Now here is one test for the 77mm F1.8 at F1.8, no hood, built in hood, new hood
what the test looked like
100% crops
Look at the contrast in the text and the effect of purple ringing on the black dots
I hope this is clear for everyone now that the right lens hood is rather quite important to improve lens performance especially on fast
primes... now the next thing i have to look for is a larger hood to fit my 24mm F1.8
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