A phylosophical question regarding lenses (so to speak...)

[Seb]

Hello,

As some of you may already know, I have been involved into photography for nearly two years now, using a simplistic Nikon F65/N65 with the kit lense (28mm=80mm, 1:3.3-5.6 G type lense).

I have now reached the point where I will switch to digital (the Nikon D70, D100 and Pentax D *ist being my 3 possible choices). I want to take advantage of the fact that I am going digital to ugrade to a better quality system rather than simply getting the digital counterpart of my current system. The 3 bodies I am looking at all represent a significant improvement over the F65 but things are more complicated when it comes to lenses.

Chances are that I will "stay true" to Nikon and I was looking at their digital specific DX lenses. The 17-55mm zoom with ED elements appeared to be the obvious choice until I found out that it was a genuine pro grade lense and that it was twice as expensive I assumed it would. On the other hand the 18-70mm zoom should be way cheaper but I doubt that it would offer a significant optical improvment over my current entry level G type lense. Finally, a third and less obvious choice could be the Tamron SP AF 28-75mm f2,8 XR DI. Choosing a third party lense doe's not naturally come to my mind, especially considering that I am fairly clueless about third party brands. However, I have read a rave review about this lense in a recent magazine and reviews right on this site are highly positive as well.

Now here's the ultimate question: consumer grade lenses against pro grade lenses, is there a signigicant difference in optic quality? It seems to me that there are two clans here: people who consider that pro grade lenses simply offer a beefier, more durable built (the difference in optics being marginal at best) and people to claim that pro grade lenses do offer a significantly better optical quality. I obvioulsy don't want to compromise on the optics yet I am not sure that I can justify spending big money on a top lense.

Any thought here would be much appreciated!

regards

Seb

[another view]

First off, I'd probably stick with the D70 (or Pentax, I don't know much about that one though). Nothing wrong with the D100, but the D70 is new technology and has some good features. Consumer vs. pro lenses is almost a film vs. digital topic - everyone will probably have a different opinion. Unless you're a professional photojournalist who's paying the rent with your gear or heading to Antarctica for the winter, you probably don't need pro lenses for the build quality. I've never heard of anyone wearing out a consumer lens from over use. You do gain other things from pro lenses though. Take the 85 f1.8 vs. the 85 f1.4 from Nikon:

The f1.8 version is about 60% less money, lighter weight, uses smaller filters and is only 2/3 stop slower. You wouldn't hesitate to throw it in your bag for a low-light lens. It's very, very sharp.

So why do people buy the f1.4? Sure, the extra 2/3 stop is nice but not that big of a deal. It looks better when shot wide open. The out of focus areas are much smoother. It uses 77mm filters like many other pro lenses (less filters or step-down rings to worry about). It's even sharper.

I saw a side-by side comparison of the images taken with both and went for the 1.4. It's heavy so it doens't go everywhere but it's a great lens on both 35mm and digital cameras. The sharpness isn't going be a factor in most situations. If you're shooting hand held you'll never see the difference. My advice would be to buy the consumer version unless there's a reason (whatever it might be) that the pro lens will be better suited for you.

[Seb]

I just came back from my usual photo shop and:

1) The sale rep was consistent with what he claimed few weeks ago; they have the D70 in exactly 2 weeks.

2) I asked about the Tamron SP AF 28-75mm f/2,8 XR Di lense and I was told that this lense is in a class of it's own. It appears that while the autofocus isn't as fast as latest Canon lenses the optical quality of the Tamron is unrivalled. According to the guy, there are no digital specific zoom with a constant aperture of f /2.8 that match this Tamron regardless of the price or brand. I was a bit surprised to hear that but since I get extremely good review about this lense from so many different sources I am thinking that I should probably get it. Beside, I actually held the said lenses in my hands and I have to say that it feel really sturdy and well built.

Seb

[Jeff82]

I use both. For me this is how it breaks out.

The better consumer zooms have optics that are very near the quality of pro lenses when shooting enlargments that are up to 8x10. I'll go farther and say the that even many non-manufacturer consumer zooms have excellent optical quality approaching that of pro lenses. However, much of this can't be realized, if you need to use 400-speed film to shoot with.

This brings me to the subject of pro prime and zoom lenses. Lens speed is the big benefit here. When I used to shoot with a 70-300 zoom, I almost always had to use 400-speed film. With my 180-2.8 I can get shutter speed in excess of 1/2000th using 100-speed film. At these speed the sharpness of the optics comes out in full when handheld. Also, faster lenses are great for zeroing out backgrounds. The whole lens speed issue is not too significant at lesser focal length, but really is much more critical at longer focal lengths.

There are other big differences too. The pro lenses are almost always internal focusing, making them much faster to auto-focus. They usually have well damped manual focus rings, and they're of much better build quality.

These days I've switched over to prime lenses for most of my shooting.

Interestingly, with digital I'm not sure that the same shutter speed requirements apply.

--Jeff