Internal focus or not?

That is the question.

Does anyone have experience with using both of these type of lenses, and what are your thoughts on the pros and cons of each type of lens?

I'm buying a macro lens , and after much research I have narrowed it down to the Tokina 100mm f/2.8. However it is not an IF focusing lens, which means that the lens extends while focusing.
The internal focusing lenses are much more expensive. I might be willing to spend the extra money if the non IF lens would be a problem bumping into the subject while focusing.

The internal focus is better, and I wish I had that, but external focus isn't much of a problem that I have noticed my friend.

I haven't used one, but keep in mind the minimum focus distance spec that they give you is from the subject to the sensor. To get the minimum working distance (front element to subject), you need to subtract the length of the lens. So you might want to search out when and how much that lens extends when you are at the distance for 1:1.

Edit:
I forgot about the depth of the camera body. From the min focus distance spec you want to subtract the length of the lens and 46.5mm for the Nikon body depth.
I found this site with a hard to follow chart that reminded me:
Macro lens calculations
If I am looking at the right lens, the tokina has a 115mm working distance or about 4.5 inches.

Sorry I can't offer any info on which is better, but that length is also a nice telephoto. Any plans on using it outside with a circular polarizer? Don't some of the non-internal focusing lenses rotate the front glass (I'm not entirely sure though)?

If you go with a non-internal focusing lens, you could always get a set of extension tubes if you find yourself working too close.

The only difference between the two is if you use a polarizer on the EF lens... Once you adjust the filter, you don't want the lens to rotate... With an IF lens, you can adjust the filter , and then change the focus point (refocus the lens) without the filter having changed without you being aware of it...

FredKingston said:

The only difference between the two is if you use a polarizer on the EF lens... Once you adjust the filter, you don't want the lens to rotate... With an IF lens, you can adjust the filter , and then change the focus point (refocus the lens) without the filter having changed without you being aware of it...

Click to expand...

Many non-IF lenses have filter threads that do not rotate. The two functions are totally independent of each other.

I have two macro lenses, the Nikon afs105mm VR, and an older Nikon AF55 D which extends to focus, the filter doesn't rotate on both lenses. If you are using AF then the internal focus would be better for sure. The way I use my macro lenses though, is I set the focus to the distance I want and it stays there, so either system works for me. I mostly prefer to use my old 55mm for my bugs etc. it's just a great lens, I don't find the external focus limits me at all.

I had the Nikon 200mm macro with IF on my 35mm gear,yes it was very sweet to use as we only had MF in those days,i now have the Sigma 105 and do find it can block light at full ext,but what i dont know is if IF keeps the front element further away from the subject at a given magnification,ie is the IF any longer in the first place.

Thanks everyone for chiming in. I think I'll just go with the Tokina 100mm.

I've owned the Tokina for about 5 years and think it's a great macro lens. You already know about Tokina's build quality. Good luck and enjoy it.

singlerosa said:

I've owned the Tokina for about 5 years and think it's a great macro lens. You already know about Tokina's build quality. Good luck and enjoy it.

Click to expand...

Thanks Jim. I didn't know you owned one. (Now I see it in your gear list).