Problems with new 500 f4 G

[Beau Cotter]

Hello, I recently got a 500 F4 G (nikon), upgraded from the 200-500. I am experiencing some issues with it sadly. Almost every shot I get out of this lens is soft. When in an enclosed environment when I test the sharpness between this lens and the 200-500, they are pretty close in sharpness, so much that it should be impossible to tell in the field. Then, when I go out with this lens, it feels great, the AF is super snappy, and the f4 bokeh is amazing! But when I come home, I see that most, if not all of the shots I took are really soft. I have AF fine-tuned this lens, and again, in a controlled environment, it is pretty accurate and sharp, maybe not quite as sharp as the zoom but oh well. (using normal AF) What in the world is going on??? Ive tried shooting at high Shutter Speeds with VR off, and I still haven't gotten anything tack sharp, even at f/5.6!!! From all the research Ive done this prime lens should be noticeably sharper than the 200-500, but so far that has been anything but the case. Any ideas of what I could do? One thing that I did notice is that it feels like the AF motor is constantly adjusting and being super erratic compared to my zoom... (again shooting at f4 is going to have a thinner DOF so I thought a bit of this would be normal, I don't know)

I really really want to get this figured out, I love this lens but if it cant take sharp photos than I am in a major pickle!!!

Example photo below

 

[Beau Cotter]

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Ok, heres a photo at 300%
200-500 on left, 500 f/4 G on the right. Also, the left one has been edited and denoised, but its very very close to the unedited shot out of the camera.

This was the sharpest image I found in a sequence of about 60 shots I took of this cardinal.

 

[Beau Cotter]

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Heres an example of that sharpest Ive seen out of this lens so far at f4, and Im completely happy with this honestly, this is great, especially for wide open IMO. And even in this situation, this was on of the only sharp ones in the sequence of shots of this junco.
(300% magnification on the D500)

 

[IainD]

That is very disappointing. There is clearly something wrong. I had this lens for a long time and I never had the AF hun ting you describe. You seem to have eliminated camera movement, slow shutter speed and lack of fine tuning (which I have never had to use on any of my lenses).
I think it might need to be looked at by service.
Only other thing is, are the contacts clean? Another slight thing- is the internal filter in place? I read once that it is needed for accurate focus.

 

[Beau Cotter]

That is very disappointing. There is clearly something wrong. I had this lens for a long time and I never had the AF hun ting you describe. You seem to have eliminated camera movement, slow shutter speed and lack of fine tuning (which I have never had to use on any of my lenses).
I think it might need to be looked at by service.
Only other thing is, are the contacts clean? Another slight thing- is the internal filter in place? I read once that it is needed for accurate focus.

I did forget to mention that the filter is not in, so hopefully that might be the cause? I talked someone who used it without and said they did not notice a difference really, but maybe that could still be the issue? Also, I just cleaned the contacts last night before taking it out this morning, so that wouldn't be the cause I don't think...

 

[IainD]

Not sure, Beau. Is it possible to put it in or is it missing?

 

[Beau Cotter]

I do not have the filter sadly, but I think I do have a random UV filter for another lens that is the same filter size, I might try that... Just to see if it would effect the AF stuff, I think its pretty cheap as far as glass quality so wouldn't use it long term.

 

[IainD]

Worth a try. Otherwise it is going to be really annoying.

 

[Lance B]

As far as I can recall, they need the filter in.

 

[Beau Cotter]

So if I have the filter in, and the problem persists, what do you think would be the next step?

 

[IainD]

Service, unfortunately.

 

[Charles Loy]

I owned a 500 f4G, never was pleased with it. At any distance, close or far.
I notice the Junco you have noise in the photo, that can interrupt the sharpness too

 

[IainD]

Mine was excellent, but a friend had a dissatisfying experience with the 600, and wished he had kept the 500. Maybe sample variation? A shame in such an expensive item, if that is the case.

 

[Beau Cotter]

I owned a 500 f4G, never was pleased with it. At any distance, close or far.
I notice the Juno you have noise in the photo, that can interrupt the sharpness too

Was it because of reasons similar to the problem with mine?

 

[DRwyoming]

To my eyes the Cardinal shot looks like motion blur, especially the oblong catchlight in the eye. How were you supporting the lens and what shutter speeds were you using?

The Junco shot looks very noisy and low contrast which makes it tough to assess critical sharpness. Again, what shutter speed, what ISO and what kind of support?

 

[Beau Cotter]

To my eyes the Cardinal shot looks like motion blur, especially the oblong catchlight in the eye. How were you supporting the lens and what shutter speeds were you using?

The Junco shot looks very noisy and low contrast which makes it tough to assess critical sharpness. Again, what shutter speed, what ISO and what kind of support?

The Cardinal was 1/800" handheld, and IIRC VR was on, f/5.6 and a ISO 200
The Junco was shot at 1/250" handheld, f4, ISO 400 (heavily cropped on the D500 gets noisy quick sadly), I was crouched down though so had more stability. VR was also on.

 

[IainD]

Ok. I was never able to get a decent shot hand held with this one. Tripod only for me.

 

[Beau Cotter]

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Here is a better example of a shot the 200-500 would've gotten spot on. Perfectly resting on the ground, and it looks like it just straight up missed? I was laying down for this one, and had what seemed like enough time to focus, but then it comes out like this.....
Hopefully it's just my technique that's to blame here, although I swear the zoom would've just focused on this junco like normal...
Thanks for all of the help so far everyone!

(300% Magnifiaction) 1/250" ISO 250, f4

 

[IainD]

It does seem to have focussed somewhere other than the bird. Could you show the whole frame? It might be helpful to see if something else is sharp.

 

[Whiskeyman]

Get a filter and install it; the filter is part of the optical formula, so Nikon will say it's an issue. Then, take it out on a tripod and see if you can get better results.

Your handheld results with 1/800 and 1/250 second exposures are similar to what I'd get. When I use my 500mm+ lenses, I want to employ a shutter speed of at least the reciprocal of twice the lens length. When I'm tired, or having a "bad day", I need to go to at least three times the lens length reciprocal.

Only if this doesn't improve the IQ of the images would I go for a lens checkout and/or service.

 

[Jerry Heitschmidt]

As far as I can recall, they need the filter in.

 

[Beau Cotter]

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Heres the whole frame, I think that stick on the right is the most in focus, although I was using Single Point AF, so not really sure why that is.

 

[IainD]

Looks to me as if the bird is best focus.

 

[DRwyoming]

The Cardinal was 1/800" handheld, and IIRC VR was on, f/5.6 and a ISO 200
The Junco was shot at 1/250" handheld, f4, ISO 400 (heavily cropped on the D500 gets noisy quick sadly), I was crouched down though so had more stability. VR was also on.

Try some shots in good light with solid support which could be as simple as resting the lens on top of a fence or table top or something else solid. Even resting the lens on a backpack or log while laying prone for low shots can work but for testing I’d eliminate any camera motion issues.

With practice, folks can learn to hand hold a lens the size and weight of the 500 f/4 G lens at 1/800” but that’s not nearly fast enough for initial lens testing with a lens of that size and weight. Remember on a D500 that has the field of view of a 750mm lens and it’s much bigger and heavier than the 200-500mm.

Hard to say if the lens has a sharpness issue but I’d withhold judgement based on these tests. I’d also consider resetting any AF fine tuning you dialed in to zero if that testing was done handheld at similar shutter speeds. AF fine tuning can make things worse if not done carefully. I’d personally only do it if I see a consistent pattern of front focusing or back focusing but not both. It’s also important to do any AF fine tuning at representative distances. IOW, don’t AF fine tune at 20’ if you’ll typically shoot subjects at 50’ or longer distances.

For handholding I’d start with shutter speeds up around 1/1600” or faster until you have a lot of experience with that much lens and possibly discover you can start dropping shutter speed.

If the lens still seems soft after doing all that then yeah I’d probably send it in for service or return it if that’s an option.

 

[Lance B]

Let's get the filter in place and then be concerned about other things if they are still an issue. AF may be affected due to the lack of filter. My 500 f4G VR was an excellent lens and was sharp as a tack.