Friday, February 4, 2011

Mid-Range Crisis!






Introduction
I've owned and used so many lenses and have shot in focal lengths from 8mm to 300mm [12-450 equivalent on DX].  As much as I love fisheyes, wide angles, macros, f1.4 primes, and f2.8 teles if I had to live with only one lens it would be a midrange zoom.

Almost all DSLR bodies will come with a kit lens that has a range of 18mm to +/- 55mm and an aperture of 3.5-5.6.  Nikon's 18-55VR and 18-105VR are the latest kit lenses available for its shooters.  Although very capable performers, they are cheaply built and don't inspire much confidence.  I wanted a lens with decent build quality, faster focus and better ergonomics.  The Nikon 17-55 f2.8 costs about $850 used and was waaay over budget. The Sigma 18-50 f2.8 and Tamron 17-50 f2.8 both cost around $300 used.  I was about to buy the Tamron when I came across a Nikon 18-70 f3.5-4.5 for $130.  I had to give it a shot!



Why the 18-70?!?!
The 18-70 doesn't have VR, has plenty of distortion, and doesn't have any significant lowlight advantages over the Nikon 18-55VR and 18-105 VRs.  However there are a few things that make this lens an attractive option.  I'll explore the negatives and positives I found about this lens and whether or not I can recommend it based on my experience.

Below is a size comparison between the Nikon 18-70 and Nikon 18-55VR.  Although similar in size the 18-70 feels a lot nicer on bodies like the D90 and up.  The 18-55 is perfect on the smallest Nikons.

|Nikon 18-70 f3.5-4.5 | Nikon 18-55 3.5-5.6 VR | 



Build Quality
Don't expect anything like the Nikon 17-55 f2.8; this 18-70 is almost completely plastic.  What it does have is a metal lens mount, rubber ass-gasket around the mount to keep out moisture and dust, and a bayonet style lens hood.  When it comes to kit lenses these are considered luxuries!



Autofocus
This 18-70 focuses WAY faster than the 18-55 and focuses slightly faster than the 18-105.  Like the 18-105 this lens has fulltime manual focus override.  This means you can grab the focus ring and readjust without any switches.  Also, this kit lens actually has a focus window.



Image Quality
Sharpness is decent wide open and improves when slightly stopped down.  Corners have a good amount of vignetting but don't always show up in shots and can be easily corrected in post processing.  A shallow depth of field can be achieved when zoomed in to 70mm.  It's no Nikon 85 f1.4 but in an emergency it would suffice as a portrait lens.

Audriana | Nikon 18-70 @ 70mm f4.5


 Cupcakes | Nikon 18-70 @ 70mm f4.5


Distortion
Distortion!  This lens has a fair amount of COMPLEX distortion.  This can't be avoided at the wide end and straight lines running through the edges of the frame will suffer from complex barrel distortion.  I didn't plan to shoot architecture with this so I was hoping I could live with it.

Blick Art Materials | Barrel Distortion [notice the shelf's edges distort outwards] | Nikon 18-70 @ 18mm f3.5

Blick Art Materials | Photoshop CS5 Distortion Correction

Photoshop has a lens correction filter that allows you plug in numbers and fix distortion, vignetting, and others lens flaws.  It's not perfect and works better on some lenses than others.  It's not perfect on this 18-70.  The corrected picture still has visible distortion flaws.

The Bad!!!
Now everything I've mentioned so far [other than the distortion] is great.  Sharpness, build quality, zoom range, and autofocus are all better than many standard kit lenses. The 18-70's build quality is especially superior to newer Nikon kits.

What killed it for me with this lens is its handling.  It could very well have been my copy but I found significant problems with how it felt to use the lens.  The zoom ring was far from smooth.  It would lightly squeak at the middle of the range and took a lot of effort to move through the focal lengths.  The focus ring was equally as stiff and difficult to use.  Lastly the lens zoom barrel is made up of two parts and sucks in air and dust as you zoom in and out.



Conclusion

I really really wanted to like this lens!  It was once a $400 lens but can now be bought for about $150-$200.  It is built nicely for a kit lens and autofocuses as fast as many higher quality alternatives.  Also, its image quality and features are all great for its market price.  However, its poor handling killed it for me.  Every time I looked at the lens I knew it would take good pictures but I dreaded having to hear that zoom squeak and feel the rough zoom and focus rings.

If you shoot Nikon and are looking for a mid-range zoom I suggest you pass on the Nikon 18-70.  If you insist on getting this lens make sure you try it out in person.  I bought mine from ebay and had no idea its handling would be so poor.  Even if you get a decent copy, the 18-70 is so old that I would be worried that its zoom and focus would soon weaken.

I suggest getting the: Nikon 17-55 f2.8 if you have the money, the Tamron 17-50f2.8 if you have ~$300, and the Sigma 18-50 f2.8 HSM if you have ~$300 and require quiet focusing.  Take my advice and never buy a kit lens if you're even lightly serious about photography.  If it came with your camera that's fine because they are completely capable of producing great images; just don't buy one if you don't have one.  Put your money towards better glass.

Hope this was helpful and happy shooting!
***I have since sold the 18-70 and ordered a Tamron 17-50 f2.8 [i should have done this from the beginning].  I'll do a comparison once I get the lens.***


Vegetables | Nikon 18-70 f3.5-4.5