View Full Version : any one has a Sigma 8mm F4 for Nikon?

nick fan
05-19-2009, 10:03 AM
Any one has the F4 version? I need to know the difference between F4 and F3.5. I have the F3.5 version.


05-20-2009, 04:57 AM
Hi Nick,

may be this can help you further

http://michel.thoby.free.fr/SIGMA8mm/Alpha%20test%20300D/ Nodal%20point%20of%20SIGMA%208... - 8k - Im Cache

i found it with google: "sigma 8 mm" and it is the article about finding the nnp of this lens.



05-20-2009, 10:11 AM
Geeze -- all ya gotta do is take some pictures of something close to the camera and look at the background to see how the foreground moves with respect to something in the middle distance back ground.

Start with a guesstimate on where the lens should go -- then move the camera back or forward 2mm each series of shots. Turn the camera so that your reference object is on the left of the viewfinder. Turn the camera so that the reference object is in the middle. Turn the camera so that the reference object is on the right of the viewfinder.

Move the camera over 1 or 2cm in 2mm steps and take the three shots and then look at the pictures.

It helps to write down the mm setting of the camera on the upper arm on a piece of paper and put that piece of paper in the field of view so you record the actual setting in the picture so you don't forget or have to figure it out. Below is an example. It aint that complicated. Takes about 20 minutes. Unless you like pining bank notes together with clothespins...