Sigma 70-300mm lens with Nikon D3100

Lauren

Hello everyone, my name's Lauren and I am new to the forum and recently decided to buy a Nikon D3100 camera after reading so many good reviews.

I recently decided to purchase a Macro lens from Sigma which is 70-300mm but I am having a lot of problems with this lens. For instance, I click on the big button to take a photo and instead of taking a photo the lens retracts and focuses on something completely different (for example the bee that was once sharp in the viewfinder is now soft and out of focus). Sometimes the camera makes a noise to take the photo but other times it doesn't at all, why is this?

What am I doing wrong? Is there a way to stop the Sigma lens from moving, or another button to take a photo with? I am a bit disappointed that the same button for zoom is the same button to take a photo.

Thank you for any help you can give.

Riddelske

I understand what your trying to describe, which I believe is the auto focus working. It will make a noise if it needs to focus on something else. There are solutions to this but they may be a hindrance to you.

First, to stop it from making the noise you would need to switch the Auto Focus (AF) off and switch to manual focus (that means turning the focus ring to adjust the sharpness/focus of your subject). The camera would no longer decide this. The AF is there for quickness depending on your situation.

Your question about the same button for zoom and taking picture I cant really understand, as the zoom is controlled via the lens itself. You turn the focal ring and that decides how far you want zoom in.

When you press the shutter button half way you're telling the camera to focus on a certain point. The camera may be set up to pick a point automatically and you can change this and tell the camera what point you actually want and then it will focus on that. To do this the AF would need to be on.

Always think compose, then focus (shutter half way if in AF), then recompose if necessary and take the shot.

Hope this helps.
If you have anymore questions feel free to ask.

GaryD3100

You probably aren't moving the button on the side of the lens to macro. It will lock the lens into the 200-300mm range and you won't be able to move it until you turn the button off. Also, I would turn AF off and focus manually. For the best shots with this lens doing macro, use a tripod.

Lauren

Thank you for all your advice.

I have switched the lens to manual focus which has solved the issue.

Thanks again.

Vanorvis

So, this lens will not work in auto focus with our D3100?

Riddelske

Yes, the Sigma 70-300mm will work with auto focus, it's just a bit loud.