Nikon 85mm 1.8G Sharpness (wide open)

[jjphotos]

Hi guys,

I was taking a few shots today with my 85mm (at 1.8) and I noticed that the photos I took were soft at the point I focused at (subject was my friend's face). I used the point focus rather than the centre weighed.

Is there a way to test sharpness and whether it's a matter of me just not used to having no VR (or doing soemthing incorrectly) or if it's the lens? Thanks.

 

[nerwin]

That's normal (to me), shooting wide open will not always yield the sharpest results. Even stopping down to f/2 will increase the sharpness substantially.

I had the 85 1.8G and I never recalled it being razor sharp at wide open, always had to be stopped down. If you want wide open sharpness, then you'd have to get the 85 1.4G haha. You gotta remember that f/1.8 at 85mm (or 127mm on crop) is very, very narrow depth of field. Your breathing alone or pressing the shutter button is enough to cause softness. Just keep that in mind.

But you could print out a focus test chart and depending on your camera, you can do a AF fine tune to "fine tune" the auto focus and see if that helps.

 

[astroNikon]

What was your shutter speed ?

as mentioned, f/1.8 Depth of Field is variant depending upon your distance to the subject and also if you are using a FullFrame or Crop sensor. ==> A Flexible Depth of Field Calculator

Not knowing any of that just makes us guess. Can you provide an example with EXIF ?

But, just for discussion if you are using a 1.5x crop sensor (regular Nikon) and shooting from 10 feet away at f/1.8 your depth of field would be 0.31 feet fore and aft of the focus point.

Of course, any movement what so ever by the camera holder including slight lmovement from pushing the shutter button with a slower shutter speed (say under 1/80 for most people) can also cause slight motion blur which will make the image look soft.

To test sharpness one must create a fixed, repeatable test. So the camera must be on a *sturdy* tripod, and be remote released, and no mirror slap (so either MuP or a delay) which will eliminate any motion by the camera. Then fixed on some detailed object(s).

Keep in mind, when wide open the center of the image may be sharp, but the corners may be soft. Whereas when you step down more of the overall image will be sharp, assuming no blur from motion.

 

[Derrel]

Insufficient depth of field at CLOSE shooting distances can render the subject liuterally in-focuis in some places, out of focus in other places. I would test the lens at about 25,30 feet on a flat wall, and check for mostly even sharpness, best in the center of the frame, a biut less good at the edges, worst in the farther corners.

This lens is SUPPOSED to be very,very sharp at normal apertures of f/2.8 to f/11. My sample of the lens is extraordinarily sharp; this model, 85/1.8 AF-S G is one of the sharpest lenses DxO Mark has tested on the Nikon D800/810 cameras...like the #4 lens out of 72 primes...the others are multi-thousand-dollar supertles, like the 200 f/2 AF-S VR-G-Mk 2 and 300/2.8 Mark II...really expeeeeeeensive lenses....

 

[adamhiram]

I find this lens to be one of the sharpest I have used, but really only in the studio. As a "fast" prime, autofocus speed is actually rather slow, and shooting wide open, particularly tighter shots, will give such a thin DoF that you will often miss focus. Pair that with needing to use faster shutter speeds with the longer focal length and it becomes apparent why it's best used for posed subjects in good light. From what I've read, the f/1.4 version really isn't much different, even at almost 3x the price.

I tend to use this lens mostly in the f/5.6-8 range, try to keep my shutter speed at 1/160s or faster, and only with flash or bright sunlight.

 

[PaulWog]

The lens should be very sharp even at f1.8.

Common mistakes:
- Focusing on the nose instead of the eyes
- Insufficient shutter speed / not holding the camera steady
- Not using the correct focus mode (don't use continuous especially at f1.8 unless you know what you need it for)
- Getting closer to the subject than the lens can handle
- Moving after acquiring focus, making the plane of focus not what you meant it to be (ex. camera is 1cm closer or further from the subject due to swaying your body); or, subject moves slightly forward or back
- Thinking that sharpness means everything looks sharp. Sharpness is measured by what is sufficiently within the plane of focus.

Common hardware issues:
- Lenses can be defective, producing soft images at all or certain apertures
- More commonly, lenses can have focus issues (need calibration) -- hopefully your camera has in-camera calibration

Other:
- This wouldn't cause your problem, but if you shoot in Jpeg, the auto processing dictates how much the image is sharpened. If you get the wrong image from the get-go, that wouldn't be the issue. However, how you decide your Jpegs to be auto-processed in camera will change certain characteristics (ex. you can set sharpening higher, but there's trade-offs).
- If you shoot in RAW, sharpening in a program like Lightroom can be done right, and it can be done wrong. For your typical shot, you usually need to weigh noise reduction against sharpening. Insufficiently exposed shots will often appear to have less detail for a few reasons, before and after recovery.
- Poor lighting can affect a lot of things (ex. accuracy of focus). Primarily, poor lighting can make a subject less interesting in the shot, and even if you accurately record the subject, poor lighting can just end up making a shot look soft and dull.

What I'd check:
- Get the camera settings correct (focus mode, exposure, shutter speed, all that).
- Set your camera still on a sturdy surface (tables can wobble so choose a good tripod or the floor or a counter), and have a good subject to focus on (something that is still).
- Select the aperture you want to test.
- Test a few shots at 3 different distances, using properly selected autofocus: Close, medium, and somewhat far.
- As you do the test, after you fire off 3 shots of your close shot, switch to "Live View" mode, and fire off 3 more shots. Same with medium and far.

This is just a quick check that you can do in order to see what the problem is. If Live View mode produces sharp images, and regular focus doesn't, then your issue is with focus calibration (the lens isn't calibrated correctly). If both regular and live view produce unsharp images, then your issue is with the lens itself (assuming your camera works with other lenses, and you didn't make an error in conducting your tests).

Your options:
- If your lens is completely defective (calibration cannot fix it), you can get repairs from Nikon or a third party, depending on where your warranty stands.
- If your lens has calibration issues, you can also send it into Nikon. I believe they ask that you send your camera in as well, so that they can calibrate the lens to the camera (a bit of an odd practice in my opinion, if one can confirm the camera focuses fine with 4x other lenses).
- If your camera has lens calibration built in, you can make adjustments in-camera (if focus calibration is the issue). Sometimes this isn't sufficient. For example, if the lens starts focusing correctly for a week, but shifts again, then you'd probably need repairs. Or, sometimes the focus problems are so far out of the range of calibration (or a bit wacky), making in-camera calibration unfeasible.
- Depending on how the lens operates, if you disclose things, you could just sell it. I've done this with troublesome lenses and recovered most of my $$$ spent (oddly I've found buyers who don't mind certain things). I find cameras and lenses come with lots of manufacturing issues all the time... it's an unfortunate thing.

 

[goodguy]

While all lenses are always sharper stepped down it doesn't mean you still cant get very sharp pictures even fully open.
Its a lot also depends of the skills of the photographer.
Here is a picture of a bride I took with my Nikon 85mm 1.8G
F1.8 This is an awesome lens and I LOVE it!!!

 

[Derrel]

Pretty bridal photo! Good use of the shallow DOF that 85/1.8 can produce.

 

[goodguy]

Pretty bridal photo! Good use of the shallow DOF that 85/1.8 can produce.

Thanks Derrel, for this shot I could have used also my 50mm 1.8G but the look on the 85mm, the compression and insane sharpness is my go to lens for this type of pictures.

 

[fmw]

The lens will have the same sharpness in the center of the frame at any aperture. Stopping down improves corner sharpness, not sharpness at the center. I second Darrel's comment that you are dealing with a depth of field issue not a lens issue. I agree with the others that the bride portrait is outstanding. The shorter lens improved depth of field. Congratulations on the shot.

 

[goodguy]

I second Darrel's comment that you are dealing with a depth of field issue not a lens issue. I agree with the others that the bride portrait is outstanding. The shorter lens improved depth of field. Congratulations on the shot.

Geee thanks

 

[jaomul]

Yip, fab bride shot. You must have been very happy with that

 

[goodguy]

Yip, fab bride shot. You must have been very happy with that

Thank you
Yes I like this one, use it in my wedding service ads

 

[benhasajeep]

As already discussed shooting at f1.8 is a very shallow DOF. The closer you get the shallower it gets. I second the first response to do a focus test with the lens. Can print a chart (there are free ones, don't fall for the paid for one's). Or can be done with a simple yard stick. Or even accurately drawn lines on cardboard (equal spacing whole length).

Not all Nikons have fine focus adjustment. Deppends on your body.

I have the D version of the lens, and I have had no reason to sell it or trade up to newer version.

 

[Shehzad]

The lens should be very sharp even at f1.8.

Common mistakes:
- Focusing on the nose instead of the eyes
- Insufficient shutter speed / not holding the camera steady
- Not using the correct focus mode (don't use continuous especially at f1.8 unless you know what you need it for)
- Getting closer to the subject than the lens can handle
- Moving after acquiring focus, making the plane of focus not what you meant it to be (ex. camera is 1cm closer or further from the subject due to swaying your body); or, subject moves slightly forward or back
- Thinking that sharpness means everything looks sharp. Sharpness is measured by what is sufficiently within the plane of focus.

Common hardware issues:
- Lenses can be defective, producing soft images at all or certain apertures
- More commonly, lenses can have focus issues (need calibration) -- hopefully your camera has in-camera calibration

Other:
- This wouldn't cause your problem, but if you shoot in Jpeg, the auto processing dictates how much the image is sharpened. If you get the wrong image from the get-go, that wouldn't be the issue. However, how you decide your Jpegs to be auto-processed in camera will change certain characteristics (ex. you can set sharpening higher, but there's trade-offs).
- If you shoot in RAW, sharpening in a program like Lightroom can be done right, and it can be done wrong. For your typical shot, you usually need to weigh noise reduction against sharpening. Insufficiently exposed shots will often appear to have less detail for a few reasons, before and after recovery.
- Poor lighting can affect a lot of things (ex. accuracy of focus). Primarily, poor lighting can make a subject less interesting in the shot, and even if you accurately record the subject, poor lighting can just end up making a shot look soft and dull.

What I'd check:
- Get the camera settings correct (focus mode, exposure, shutter speed, all that).
- Set your camera still on a sturdy surface (tables can wobble so choose a good tripod or the floor or a counter), and have a good subject to focus on (something that is still).
- Select the aperture you want to test.
- Test a few shots at 3 different distances, using properly selected autofocus: Close, medium, and somewhat far.
- As you do the test, after you fire off 3 shots of your close shot, switch to "Live View" mode, and fire off 3 more shots. Same with medium and far.

This is just a quick check that you can do in order to see what the problem is. If Live View mode produces sharp images, and regular focus doesn't, then your issue is with focus calibration (the lens isn't calibrated correctly). If both regular and live view produce unsharp images, then your issue is with the lens itself (assuming your camera works with other lenses, and you didn't make an error in conducting your tests).

Your options:
- If your lens is completely defective (calibration cannot fix it), you can get repairs from Nikon or a third party, depending on where your warranty stands.
- If your lens has calibration issues, you can also send it into Nikon. I believe they ask that you send your camera in as well, so that they can calibrate the lens to the camera (a bit of an odd practice in my opinion, if one can confirm the camera focuses fine with 4x other lenses).
- If your camera has lens calibration built in, you can make adjustments in-camera (if focus calibration is the issue). Sometimes this isn't sufficient. For example, if the lens starts focusing correctly for a week, but shifts again, then you'd probably need repairs. Or, sometimes the focus problems are so far out of the range of calibration (or a bit wacky), making in-camera calibration unfeasible.
- Depending on how the lens operates, if you disclose things, you could just sell it. I've done this with troublesome lenses and recovered most of my $$$ spent (oddly I've found buyers who don't mind certain things). I find cameras and lenses come with lots of manufacturing issues all the time... it's an unfortunate thing.

Very very informative post,really
I have problem may u solve.i am beginner,just got 85mm 1.8 at 610 body.
When I was done a couple shot before some days,I was shocked when I found that both were not properly..bride eyes n near area was sharp but her jewellery or dress were not sharp.
Pls advice what I can do when
I WANT COUPLE FULL LENGTH PICTURE PIN SHARP WITH BLUR BACKGROUND.
thanks