Lens quality between brands

Bytesback · Feb 4, 2014

Hey all, had a question for anyone who may have the experience/knowledge to answer.

A few months back, I got a Tamron AF-S 70-300mm f/4.0-5.6 lens for my camera; to shoot some of the many hawks/falcons/eagles that reside in our valley. Now while I love the lens, I've noticed theres big drop in the focus speed when the subject is flying/moving, making any kind of flight shots almost impossible since birds tend to fly away faster than the lens can focus on it. I have been eyeing Nikons version of it on amazon for some time, wondering if Nikons would be any faster, or would be worth it to spend the extra cash and get it.

Any insight you can provide would be appreciated. Also, I am very new, so if I am missing something please feel free to educate me, but do not be rude or impolite about it.

Thanks!!!

Bytesback · Feb 4, 2014

Oh, and I bought the Tamron lens used on Amazon, but the seller described as "Like new"(sellers never lie right? :wink:

), so maybe thats why the lens focus speed is slow?

jaomul · Feb 4, 2014

What camera and what settings are you using that you find the lens focuses slow?

Bytesback · Feb 4, 2014

I'm using a nikon D3100. When I am shooting the hawks, and see they are about to take flight, I will usually put it on shutter priority with a speed of 1/300- 1/500. I am still too new to have a perfect handle on Manual Mode.

jaomul · Feb 4, 2014

Another thing or 2, have you the autofocus set to continuous, or auto? Is it Tamrons newer with vc or without?

Bytesback · Feb 4, 2014

The autofocus is set to auto. I'm unsure about VC, as I do not know what it is

jaomul · Feb 4, 2014

VC will be written on the lens. it is the newer tamron that has vc (vibration compensation). this lens also has an ultrasonic motor, I had this one but if its the one without, it may say macro 1:2 somewhere on the lens. The older one is slower to focus.

Firstly i am not a birder but do a bit. Set your camera to continuous focus, it will be written in the manual somewhere. I would then select your centre focus point. This will be the one thst you will try and keep on your bird as you are following it. Shutter priority is fine but I suspect you will get better results at 1/1000th of a second. Set your iso to auto. the camera will then select 1/1000th sec with the largest aperture possible combined with a suitable iso.

this is a very simplified start out point. The d3100 is nice but it doesn't have as fancy an autofocus system as more sdvanced models. The Tamron is nice, either one. The one with vc on it is better (if you have this one turn vc off as your shutter speed is above its requiremement and this can slow the lens down), but they are consumer lenses and wont focus as fast as pro lenses. What I am saying is you have a nice kit but it may have limitations for birding. try out the initial settings and see how you get on. I am sure more experienced people will chime in later with even better alternatives. Oh your iso might go up due the shutter spped but a bit of noise is better than motion blur. Good luck

Bytesback · Feb 4, 2014

Jaomul- Thank you for the informative response! To select the center focus point, would I go in and change metering to center instead of matrix? I will also try raising my shutter speed. I should just switch over to manual, but I gotta admit that learning everything that goes into a photo when shooting a dslr is a little intimidating. Thanks again for the information, I will try this the next time i get out.

jaomul · Feb 4, 2014

The metering is seperate to the focus point. I would be inclined to leave the metering in matrix for the moment. I would not even try these kind of shots in manual. There is no advantage really. The semi-auto modes such as aperture priority and shutter priority are more used than manual by an awful lot of photographers. If you hang a nice bird photo on your wall it doesn't matter if you shot it in manual or shutter priority. You are still making the creative call by selecting shutter speed and knowing what the camera will do at this setting

Bytesback · Feb 4, 2014

I am glad to hear that! I have been watching some instructive videos on Manual mode, and while its not as intimidating as it was, I am still only going to try it on more "controlled" shots, where I don't have to worry about the subject flying away in a matter of seconds. So if metering is seperate from focus point, where would I change focus point on the camera?