Cameras, Lenses and Accessories

petesmit · #1 (**permalink**) 03-01-2009, 10:22

I recently got a Nikon D90 and decided to also get a Sigma 150 -500mm as the equivalent Nikkor Lens would cost a fortune. Wondering if I have got a duff lens as sometimes but not always when using Autofocus the lens just adjusts itself to a completely blurred iamge and the shutter release doesn't work (not that I'd want a blurreed image anyway) Anyone any experience of using the same kit or ideas generally would be very much appreciated

**Ogofmole** · #2 (**permalink**) 03-01-2009, 11:15

Hi Pete, If you have the 'Autofocus' set to single, you will not be able to take a photo unless the camera has focussed on something in the image, if you set the 'Autofocus' to continuous, then your camera will take the image, this is useful at sunset where there is very little contrast for the autofocus to lock onto. As for your lens, I have seen some very good images taken with this lens (look on flickr), but if you are using the lens at the 500mm end make sure that you are pointing at something with good contrast otherwise use manual focus. Also if the lens has a focus limit switch on it then use it if you are taking shots at the longest end of the lens, as this will help with the autofocus.

extruckie · #3 (**permalink**) 03-01-2009, 11:52

I think this shows what phototopix is all about. A newbie asks a question and within the hour, he has an answer. Bl**dy fantastic! SUPER site.
Happy New Year to all.

**Dennyboy** · #4 (**permalink**) 03-01-2009, 12:32

Quote:

Originally Posted by extruckie

I think this shows what phototopix is all about. A newbie asks a question and within the hour, he has an answer. Bl**dy fantastic! SUPER site.
Happy New Year to all.

Barry, glad you are back mate, but an hour! What kind of service is that

Same answer i would have said so great minds and all that!

Pete call us TESCO "always happy to help"! Has it worked is the question??

carregwen · #5 (**permalink**) 03-01-2009, 12:59

Canon cameras have an auto-focus aid but the Nikon D90 has an AF assist beam for low light focusing compared to the Canon EOS 50D were the flash has to be raised in order for the AF assist feature (multiple bursts from flash) to function. Not sure it's much good though on long shots such as distant landscapes.

petesmit · #6 (**permalink**) 04-01-2009, 07:27

Many thanks to you all for the great responses. I will try the different Autofocus settings you mention Barry the continuous one you mention I assume to be AF-C (Continuous servo AF) on my D90 as opposed to the single default setting AF-A

Pete

**Ogofmole** · #7 (**permalink**) 04-01-2009, 10:17

Quote:

Originally Posted by petesmit

Barry the continuous one you mention I assume to be AF-C (Continuous servo AF)
Pete

Correct

Quote:

Originally Posted by petesmit

my D90 as opposed to the single default setting AF-A

Pete

Correct, although this is the setting that I use most of the time, unless I'm taking moving wildlife (like birds) or motorsport where I would use AF-C.

samstewart · #8 (**permalink**) 15-12-2009, 23:51

I currently have a D90 and am strongly considering getting a 15-500mm sigma. I would like it for wildlife (birds mainly) what does everyone think???

Good lens/Not good lens

**Ogofmole** · #9 (**permalink**) 16-12-2009, 18:38

Hi Sam, We have got a few members who have used this Lens with great results especially wildlife shots, here is a review.

Sigma Lens: Zooms - Sigma 150-500mm f/5-6.3 DG OS HSM APO - SLRgear.com!