Nikon 85mm f/1.8G

So I recently received the Nikon 85mm f/1.8 G lens in the mail and decided to give it a test run.  The way I like to do these field tests is to take the lens out with the family on a walk.  This gives me time to play with the lens and test its various features based on the broad range of challenging photographic situations my family create.  As anyone who has ever tried to take pictures of kids can attest they are some of the most challenging subjects to shoot.

Why I bought it:

In terms of cost I paid around USD 500 for this lens which is a mid ranged price as far as I am concerned.  I purchased this lens specifically to take pictures of the family.  I wanted something where I could get a 3/4 portrait shot without standing back a mile away.  I wanted something fast to be able to shoot in low light.  And I wanted something sharp.

If I do a search in Lightroom most of the shots I take of family is in the larger aperture ranges and higher ISO.  This is because the kids move fast so I need to keep the shutter speed fast and most of the time we are in doors.

First Impressions:

Out of the box I noticed that it was very light.  It is made from a plastic body with metal mounts.  The lens focuses internally which means it does not change length.  It has an odd 62mm filter size and is made in China.

So the good news is that it is light and fairly well made.  The downside is that this is not a touch lens so if you are going to be rough with it I would suggest a sturdier lens.

Field Test Plan:

I took the kids out to a park and took my D800 with the 85mm lens on.  It is a good walk so I wanted to capture the kids on our walk there.  With the long walk I was thankful for its light weight.  I can carry this thing all day long.

The kids were going to play on the playground which ensured they would move a ton.  The sky was completely cloudy giving me the chance to open up the apeture as wide as the lens could go.  It also gave me some even lighting to really see what the lens can do.

Overall Impression:

This lens is indeed sharp.  Here is the thing about sharpness though…it is relative.  By this I mean that if I take a lens, mount it on a tripod and shoot a stationary object then chances are good it will be reasonably sharp.  If I take a lens with a widest aperture of 4.5 or so the lens might be very sharp on this test but when I take it to the field it may not be vary sharp and here is why…

When you cannot get a aperture open very wide the lens cannot let in much light which means you need a longer shutter speed.  This longer shutter speed means that you are not freezing motion as much as you could with a shorter shutter speed which, in turn, means you shots will be less sharp.  If you increase the ISO you can reduce your shutter speed but you will introduce grain and will end up using software to remove the noise at the cost of sharpness.

So a fast piece of glass gives you the ability to open up the aperture and reduce your shutter speed to really freeze motion.  If you are in the 1/500 sec or faster range then there is a much better chance of getting a sharp image.

So with a 1.8 aperture capability the chances of getting a sharp image are rather high.  The key thing to remember is that you will have a very thin focal range which means that even a slight bit of movement closer or farther away from your subject will instantly loose sharpness.  Keep your continuous focus turned on to improve results.

This lens is indeed sharp.  I was able to capture flies in several shots.  That I could zoom into the fly and see its wings tells me that I have a great resolution sensor (D800) and that the lens is well into the acceptable range of sharpness.

One disappointing thing about the lens is that it does not focus very fast.  It is not nearly as fast as my professional f/2.8 gear which is unfortunate.  That small lag really does make me loose some shots.  When kids are sitting still you have to move fast and I need that focus to be tack sharp in an instant.

Sample Shots:

Gabriel In Field (Perth, Australia): D800 85mm, shot at 85mm, f/1.8, 1/1250sec & ISO 100.

So here is my 3 year old Gabriel.  He was running around all day but I managed to get down to his sight level and follow him with the focus to capture this shot.  You can see I am wide open at f/1.8 and the background is nice and soft.  He is sharp (focused on his eyes) and the fall off is gentle.

Lucas on Gym (Perth, Australia): D800 85mm shot at 85mm, f/1.8, 1/250sec & ISO 100.

In this shot I have my middle child Lucas.  He stood still for this shot allowing me a bit of time to get the focus right.  The lens is plenty sharp with soft background.  If you see the yellow pole behind him this was about three feet behind him.  You can see it getting very soft in a short distance while his eyes and nose are still in focus.  So the focal plane is narrow but acceptably so.

Sabrina Swing (Perth, Australia): D800 85mm shot at 85mm, f/1.8, 1/1250sec & ISO 100.

This final image we see my daughter on a swing.  I pre-focused to capture this one.  It took me three shots to capture it because of the slow focusing.  This would have been a single shot capture using my Nikon 24-70mm.

That being said it is nice and sharp and the background is wonderfully blurred.

Overall Verdict:

Simply put I would buy this lens again.  I do not believe that the added speed and sharpness of the Nikon 85mm f/1.4 is worth paying three times the price.  I like that it is light and and thrilled with its sharpness and fall off.  The lens has some vignette but Lightroom fixes this with a click of a button.  The odd filter size is annoying but not a shot stopper.  The build quality is good enough and I am sure it will give me years of joy.