Nikon 50mm 1.8G not sharp

Hi guys, so last week I bought the legendary Nikon AF-S 1.8G 50mm. But I noticed that the photos where kind of weird. The new lenses photos where over exposed and not sharp. I took them completely in Manual mode on a d3400.

The DSC_2270 photo is the (50mm 1.8g af-s)

The DSC_2271 photo is the (18-55mm 3.5-5.6g af-p dx vr)

Both at 1/40 f/5.6 50mm iso 100. And it wasn't windy.

Is it normal for this prime to take photos like this?

If it's stuck open at F/1.8 this would also explain overexposure.

Overexposure of the prime lens image is at most 1EV - not the more than 3EV expected if the aperture were stuck wide open.

For the image with the zoom, EXIF claims a focus distance of 13.34m, for the other it's 6.31m.

There's also a "mysterious" (to me) EXIF entry called "Exposure Difference" that's show +0.8 for the zoom image and +0.2 for the prime lens one. About the difference in exposure between the two images - I just don't have a clue what that parameter refers to.

Lastly, VR on for the zoom; obviously no VR for the prime lens - and the prime lens image shows motion blur (likely from camera shake).

EDIT: just checked with the EXIF viewer info: Exposure Difference is "Difference in actual and metered ambient exposure, usually zero outdoors, usually large indoors with flash"

Still don't know what camera setting that refers to. Or maybe I do: shot fully manual - the parameter indicates how far off the exposure was. Possible reason for the difference - different light transmission (T-stop) between the prime and the zoom?

Overexposure of the prime lens image is at most 1EV - not the more than 3EV expected if the aperture were stuck wide open.

For the image with the zoom, EXIF claims a focus distance of 13.34m, for the other it's 6.31m.

 

There's also a "mysterious" (to me) EXIF entry called "Exposure Difference" that's show +0.8 for the zoom image and +0.2 for the prime lens one. About the difference in exposure between the two images - I just don't have a clue what that parameter refers to.

 

Lastly, VR on for the zoom; obviously no VR for the prime lens - and the prime lens image shows motion blur (likely from camera shake).

 

EDIT: just checked with the EXIF viewer info: Exposure Difference is "Difference in actual and metered ambient exposure, usually zero outdoors, usually large indoors with flash"

 

Still don't know what camera setting that refers to. Or maybe I do: shot fully manual - the parameter indicates how far off the exposure was. Possible reason for the difference - different light transmission (T-stop) between the prime and the zoom?

About the focus distance I don't know what happened, at most I was some cm to the side. Maybe I wasn't focusing at the same branch, but 7 meters difference?

About exposure compensation I had both at 0, so I don't know what else I can config in my camera.

And the VR, probably that's a big cause. Tomorrow I will post 2 more pictures of fixed objects, and I'm going to put the camera on something so that it doesn't shake. (I don't own a tripod).

Sorry for making you guys loose time with amateur errors.

So now it's night time, I can't take pictures outdoors.

The DSC_2286 is the zoom lens.

The DSC_2287 is the prime.

With the zoom lens you can read the video title on the bottom right, the prime you can't.

Both at iso 800 1/250 50mm 5.6

EDIT: Both focusing in the middle of the screen, and the camera was put on top of a fixed object.

Try LV focus, cam on a tripod with VR off at f5.6 @ a nice target ~ 4m away.

If that's not sharp, the lens is bust.

The daylight picture taken with the f/1.8 G lens shows all the hallmarks of camera shake. Did you use a tripod?

Handholding at 1/40th is inviting camera shake with no VR available on the lens. Whereas the kit zoom has VR.

Also, a very slight shift in focus can make a world of difference to slightly out-of-focus subject areas.

My opinion is that far more careful testing of your new lens needs to be done before any conclusion can be drawn.

Lenses almost never get more unsharp between open aperture and f/4. That's the range of aperture I'd be testing a fast prime at. And I'd choose a flat subject with plenty of detail, not a monitor screen that provokes moire patterning. I'd also have the camera tripod mounted and use flash illumination to be doubly sure of eliminating vibration. Auto-collimating the lens and subject with a small mirror is also a good idea, as is bracketing the focus in tiny steps to eliminate any focus-related blurring.

With the zoom lens you can read the video title on the bottom right, the prime you can't.

Come on, man! The photos of the test pattern on the computer screen are tilted. The left side of the monitor is closer than the right. This is not a good test.

The fact that the zoom shows the text in the bottom right corner legibly and the prime does not doesn't mean the prime is less sharp. Indeed, if you look only at the center of the test patter, the prime looks sharper. The bottom right corner is less sharp, but there could be various causes. For one, the camera may have front-focused with the prime, causing there to be less depth of field behind the focus point. (You may need to AF Fine Tune the camera with the 50mm lens.) For another, the prime may have more field curvature than the zoom (at 50mm).

More rigorous testing is needed.

The new lenses photos where over exposed and not sharp. I took them completely in Manual mode on a d3400.

Well, that kinda implies you overexposed it, not the camera or the new lens....;)

Take focus adjustment and fine tuning out of the equation and just do a tripod based LV focus experiment. It should use Contrast Detect AF, which relies on what the sensor actually sees, so is, in theory, the most accurate test you can do.

Hi guys, so last week I bought the legendary Nikon AF-S 1.8G 50mm. But I noticed that the photos where kind of weird. The new lenses photos where over exposed and not sharp. I took them completely in Manual mode on a d3400.

The DSC_2270 photo is the (50mm 1.8g af-s)

The DSC_2271 photo is the (18-55mm 3.5-5.6g af-p dx vr)

Both at 1/40 f/5.6 50mm iso 100. And it wasn't windy.

Is it normal for this prime to take photos like this?

 

[ATTACH=full]1314190[/ATTACH]

 

[ATTACH=full]1314191[/ATTACH]

Did you also try APerture preference? if so what shutter speed did the camera choose ?

Still don't know what camera setting that refers to. Or maybe I do: shot fully manual - the parameter indicates how far off the exposure was

Indeed,

It's gotta be the 'extra exposure' the OP chose to dial-in over the indicated exposure.

If the D3400 has an internal - >+ exposure indicator bar, I guess they dialled in +0.8 or 8/10ths of an EV above what it suggested.

For the screen shot images, the exposure differences persist; -0.7EV for the prime lens shot and -0.2EV for the zoom.

The photos of the test pattern on the computer screen are tilted. The left side of the monitor is closer than the right. This is not a good test.

Indeed. The moire pattern also seems to indicate that the focus with the zoom is farther to the right than with the prime - handily explaining why the lower right hand corner appears sharper with the zoom than with the prime. The tilt is also more pronounced for the zoom image.

just do a tripod based LV focus experiment

+1

Daniel,

For the daylight images. Your images are soft all over. There is no point of sharpness. This is likely due to camera shake. The general camera shake rule for shutter speed with 35mm or full frame DSLR is shutter speed should be at least 1/focal length of a non stabilized lens. The angle of view of your 50mm lens is equivalent to that of a 75mm lens since your shooting a 50mm lens with a DX 1.5 crop body into full frame. I would shoot hand held at 1/80 of a second or faster as a starting point. More over 1/250 is far better and would probably obviate any motion from hand holding if your standing still with little to no wind shooting a static subject that your not having to track. Don’t worry we all make this mistake. A tripod would be best.

The second set of images do not assure that there is no sensor pitch or yaw that changes the angle of the focal plane and therefore the focus on certain parts of the image as you change lenses. The sensor is so small that any subtle change of angle when you change lenses especially with a larger target will be appreciated.

If you can fully control these parameters then I think you may be right but at this point I can’t be convinced it’s the lens and not the operator. Thanks for sharing your camera settings.

The least expensive way to test your camera’s exposure is to compare it with other cameras using the same lens. Another way is the Wallace Expodisc. I have owned one for years. It came from the factory with hand inscribed calibration correction for the disc itself. In recent years it has become even more popular for white balance. It will help you nail down exposure error on your camera/lens combination. The d3400 is a great camera and so is the Nikon 50mm f1.8 AF-S G.

Don’t give up.

Sorry guys for making you wait so much.

I received today my tripod so the first thing I did was test again.

Almost clear sky, no camera shake because of tripod, some moving objects like leaves on light wind, and not moving objects like the parked cars.

Fully manual didn't even touch any button while changing lenses(18-55mm 2526.jpg)(50mm 2528.jpg)

Aperture mode both 5.6 (18-55mm 2533.jpg)(50mm 2530.jpg) (Camera decided to change shutter speed)

Fully auto (18-55mm 2536.jpg)(50mm 2537.jpg)(camera changed aperture and ISO)

There's a consistent difference in the focus distance being reported - the 18-55 images are at 13.34m and the 50 images at 6.31m. Assuming you focused on the same spot and given that the 18-55 are sharp and the 50 images are soft, there appears to be an issue with the 50; that's also assuming that those reported distances are actually accurate and that both lenses would report the same value for the same distance (the reporting is in discrete steps and they may differ from one lens to the other).

Have you tried focusing via live view? This is a necessary test now to determine whether the 50 is just a bad copy or whether it's an AF fine tune issue (though the focus error might well exceed the range of AF fine tune parameters). If the sharpness difference persists when focusing was done in live view, then the 50 needs to be returned to the store (or send to Nikon to be worked on - which might not be an economically viable option).

The exposure difference appears to be due to the difference in light transmission between the two lenses - though I am surprise by the magnitude of it.

There's a consistent difference in the focus distance being reported - the 18-55 images are at 13.34m and the 50 images at 6.31m. Assuming you focused on the same spot and given that the 18-55 are sharp and the 50 images are soft, there appears to be an issue with the 50; that's also assuming that those reported distances are actually accurate and that both lenses would report the same value for the same distance (the reporting is in discrete steps and they may differ from one lens to the other).

 

Have you tried focusing via live view? This is a necessary test now to determine whether the 50 is just a bad copy or whether it's an AF fine tune issue (though the focus error might well exceed the range of AF fine tune parameters). If the sharpness difference persists when focusing was done in live view, then the 50 needs to be returned to the store (or send to Nikon to be worked on - which might not be an economically viable option).

 

The exposure difference appears to be due to the difference in light transmission between the two lenses - though I am surprise by the magnitude of it.

Sadly my camera doesn't support AF fine tune, I will try to focus manually. Could it be that these problems are happening because the camera is dx and the lens is fx?

Sorry guys for making you wait so much.

I received today my tripod so the first thing I did was test again.

Almost clear sky, no camera shake because of tripod, some moving objects like leaves on light wind, and not moving objects like the parked cars.

 

Fully manual didn't even touch any button while changing lenses(18-55mm 2526.jpg)(50mm 2528.jpg)

Aperture mode both 5.6 (18-55mm 2533.jpg)(50mm 2530.jpg) (Camera decided to change shutter speed)

Fully auto (18-55mm 2536.jpg)(50mm 2537.jpg)(camera changed aperture and ISO)

Seems to me your 50mm has some kind of alignment or spacing issue with its elements. While the center is blurry, the left and right edges at the same depth as the center point (on the grass) are sharp. This is not accounted for by the normal field curvature of the lens, which is minimal. This copy is a dud and should be returned, if possible.

Without being picky...:)

Nikon Nikkor AF-S 50 mm f/1.8G review - Image resolution - LensTip.com

2.8 isn't that great...:(

5.6/8 maybe.

That being said, it's awfully cheap and just plain awful IQ wise..

The 1.4 version is very expensive, and not much better.

If you want sharp wide open, leave Nikon standard primes alone.