Nikon 24-85mm f/2.8-4 ED IF lens review

I was looking for a standard zoom for my Nikon D700 when I made the purchase and got a very good deal on this lens so I bought it. I was more interested in the Nikon 24-70mm f/2.8 AFS G lens at the time so I tried one at the shop and also tried my friend's lens. The 24-70mm f/2.8 is a very heavy lens and I decided to give the 24-85mm a try before I decide to sell it.

I was primarily using the 24-85mm as my main lens and I have been shooting extensively with this lens. This is my very subjective opinion about this lens. This pertains to FX format but most of it holds good for DX format also but this becomes a 36-129mm in DX format so something to keep in mind.

This is the current lens in the Nikon line up so it is not weather sealed but of adequate build quality. I am not the person who looses sleep overbuild quality since half of those who comment on it do not have a clue about the materials used. In modern lens standard the only relevant question is weather sealing. All else is immaterial. Most people do not realise that expensive lenses withstand the same amount of abuse as this one baring weather effects. I will try to expand on this in some future blog. But suffice to note that this lens will take a lot of abuse before showing signs of it. The zoom is smooth and precise. There is no creep or other issues. The lens is internal focusing so the front element does not rotate, makes it useful if you use a polarizer.


Autofocus:
This is a Screw-drive lens meaning that there is no internal motor but relies on the camera to focus. This translates to the effect that the AF speed will depend on your camera also. On a D700 AF is fast and precise. You will not loose any shots due to the AF speed. The closest focus is 0.5 m.

(For in depth explanation of various Auto focus settings and custom modes in auto focus for users of Nikon D700 D3 and D300 please seehttp://prakashphotography.blogspot.com/2008/12/nikon-d700d3d300-autofocus-settings.html)

Manual Focus:
This lens is optimised for AF. MF is possible with a switch. It is easily workable as a MF lens if need be but not as fluid as dedicated MF lens.

Vignetting:
There is some vignetting at the widest end (24mm) which is easily correctable with software (I have used both lightroom or Capture NX2 to good effect). The vignetting is gone by the time you stop down to f/4 or f/5.6. There is also decrease in vignetting as you go from wide to tele. For practical purposes vignetting is not a problem.

Chromatic Aberration:
This lens handles CA very well and I could not recall any photos where I had any significant CA.

Distortion:
There is moderate barrel distortion at the wide end with curvature of field. This is typical of a zoom lens. The 24-70mm G lens also has similar distortion.

Resolution:
This lens has excellent resolution that is better than 35mm f/2 at 35mm and almost as good as 85mm f/2 Nikkor. I have no experience with 85mm f1/8. You will be hard pressed to fault this lens based on its resolution.

Macro:
Not a true macro. Excellent close focus of about 21cm. You cannot go wider than 35mm in macro mode. But at 85mm you get 1:2 which is very decent macro for a zoom lens.
Important tip: Switch to normal mode from macro when you want to zoom wider than 35mm otherwise you will not be able to go beyond 35mm. Another important consideration is to focus beyond 50 cm before you will be able to switch from macro to normal mode. Remember this otherwise you will think that the lens malfunctions.

Contrast:
There is some loss of contrast wide open but contrast become very good as you stop down. This is where the 24-70mm G pulls ahead. The expensive zoom has spectacular contrast even wide open.

I still have the 24-85. The reason is this is such a good walk around lens for Nikon full frame. The lens has excellent resolution and decent in most parameters. Most importantly this is such a light weight lens. Personally the weight is the only factor that prevents me from switching to 24-70mm AFS. By no means am I suggesting that the 24-85mm is a better lens. What the 24-70mm gets you is slightly better distortion control, better contrast, uniform aperture of f/2.8 and better build quality. Only the user can determine if it's worth more than $1000 price difference.

For FX format Nikon this is the best walk around lens considering the price, performance and weight factors. I have briefly used the 28-105 but was not impressed either with resolution or with the wide end. No its not a bad lens but the 24-85mm is definitely better. If you are buying this lens used there is no better bargain. For comparison let me put this in a way I am familiar with. I have used most Canon zooms which are excellent by the way and this 24-85mm is as good as the Canon 24-105mm f/4L which I owned and is a great zoom in its own way. This is one of the few things that Nikon has impressed me with. They really don't hold back on consumer zooms and give the best possible within that price range.

Check my impression on the Nikon 70-300mm VR AF-S here

Some photos with this lens:

Autofocus Microadjustment

I had the opportunity to use both Canon 5D MKII and Nikon D700 recently and I found one of the new advances in the last year was AF Microadjustment feature these new cameras offer. This feature is extremely useful for both consumers and the camera makers and helps you save a lot of time in sending lenses back to the company for calibration.

You may already know that DSLRs and lenses like most products have manufacture tolerances. If the camera or lens focuses, say within +/- 3 then it may be acceptable for the manufacturer. But if your camera is +3 and your lens is also +3 then you may have focus issues. The most common cause for front or back focus is because of this.

Focusing accuracy is the second most important factor in image sharpness (after blur due to camera shake). So if your lens looks to be not sharp enough this is worth a try to rectify your problem.

If you own one of the newest cameras from Nikon or Canon (I am not sure about other manufacturers) then you should have this feature. In Nikon this feature is available in D300, Nikon D700, Nikon D3 and Nikon D3x. In canon this feature is available in Canon 50d, Canon 5d mark II and also in 1 DS & 1D mark III.

(For in depth explanation of various Auto focus settings and custom modes in auto focus for users of Nikon D700 D3 and D300 please see http://prakashphotography.blogspot.com/2008/12/nikon-d700d3d300-autofocus-settings.html)

I have used this feature in both Canon and Nikon and I will go through this set up process.

AF MICROADJUSTMENT:

For this you need the test image which you need to download (links below) and use LIVE View feature in your camera. The adjustment process uses Moire interference patterns produced by these images when they are in focus.

You need to put your camera on your tripod. You need to have the image on your computer screen (Please don't print !!!). If possible use a monitor, instead of laptop screen. Use Live View to manually focus. Do it slowly and carefully and a patience helps a lot in getting your focus accurate and also use less tries to get it set up.

Here are the steps:

(Please note these steps best work for f/2.8 or faster lens. If you use f/2 or faster primes this method may or may not work, please see below another method for these fast lenses)

1. Bring the Test image on your screen. Make sure it is at 100% size on your screen.

2. Place your camera secure on a tripod. Level it by viewing the center of the image on the screen (do not bother about focus now). Turn off VR, IS features if your lens has one. Make sure the camera lens and monitor screen are parallel.

3. Place the tripod so that the lens is beyond the minimal focus distance at its longest focal length (if it is a zoom, ex. for 24-70mm use minimal focal distance at 70mm). If your lens can focus to 1 meter then set the tripod at 1.2 to 1.5 meters.

4. First turn on Live view. Use Aperture priority mode and use maximum aperture for the lens (as wide open as possible). Set your lens to manual focus.

5. Use Live view screen to manually focus your lens till you see the most significant Moire pattern on the Live view.

6. Now without moving your camera or lens set your lens to Autofocus. Set your camera to single shot AF. Manually select center AF point for focusing. Next half press the shutter while you watch the focus distance scale of your lens.

7. If your lens focus distance scale did not move then your lens does not need any AF microadjustment. Go back to live view and make sure the moire pattern has not changed. Repeat this process if needed to make sure.

8. If your lens focus scales did move then you need to make AF Microadjustments. Go to Set UP menu in Nikon to access AF fine tune or Custom Fn. III in Canon to access AF microadjustment (set to adjust by lens). Now if the distance scale moved clockwise dial in (-) or if it moved anticlockwise dial in (+). Dial in 5 or 10 depending upon the movement. If you make a mistake and dial in + instead of - your focus will be way off so you should be able to recognise this. Keep changing the AF adjustment till the focus scale does not move. Once you are done do not forget to save this setting for this lens. You have to press the info button in Canon and the OK button in Nikon otherwise none of your settings will be saved.

That's it you are set for this lens.

Well his method works for zooms whose widest aperture is f/4 or smaller. But for primes f/2 and larger, I did not found this method to be efficient. These fast lenses have razor thin DOF and the above method is not very accurate. So I created my own way of adjusting AF fine tune. Please give it a try you may find it very accurate.

You can always get the commercial available tool for this at www.rawworkflow.com/lensalign but if you want to save $140 you can try my method.

Basically I use a remote. You can use any remote that has numbers. It is readily available and no one should have problems finding several in your homes.
Now I think this is a very good method. This method is copyrighted by me and me alone and you can try it free but if you post it elsewhere my international copyright attorney is watching every website in this planet and you will be found and brought to justice. If it does not work the fine print says I am not liable. Beware of my legal entourage. Okay just kidding. Here goes my innovative method.

I selected a remote and not a ruler because in a remote each number has its own button which is 3 dimensional and so your accuracy will be very high.

1. Place the remote on a flat surface or better at 45 degrees.

2. Place your camera and lens on a tripod at a distance just beyond the near focusing distance (with the lens at maximum zoom if it is a zoom).

3. Focus on any number in the middle of the remote. Make sure there are numbers below and above this.

4. With your lens wide open and your camera set to single point AF take pictures. Examine the photos at 100% and check for AF accuracy.

5. If your photo shows that the focus is exactly on the number you tried to focus and if the numbers in front and behind are blurred then your lens does not need any AF microadjustment.

6. If your photo shows that the number behind the one that you tried to focus is sharp then dial in + adjustment. If the number in front is focused then dial in - adjustment. Keep repeating this till you get your number in sharp focus. Once you get a sharp focus save this AF microadjustment. You are done.

The only suggestion is to improve accuracy and ease is try to find a remote where the number spacing is such that you get only one row of numbers in focus with the front and back rows blurred. This should be very easy if you have 2 0r 3 remotes in your home.

As usual your comments are greatly appreciated.