How do you fine tune the 300mm 2.8 or 400mm 2.8 nikon's: I have a 300mm 2.8 that has been checked out by Nikon and they say it is within specs. Well it is fine tuned to a -18 and it...

farwest Loc: Utah

I have a 300mm 2.8 that has been checked out by Nikon and they say it is within specs. Well it is fine tuned to a -18 and it still back focuses on my D500 which has no problems with any of my other lenses. It also backed focus with my D4 which I sent in and they changed the lens mount it has to be a -15 to focus correctly. So do I send the lens back in or what? I would be nice to have a lens that works correctly. It is not under warranty.

Thanks

sumo Loc: Houston suburb

Focusing Charts
http://mansurovs.com/wp-content/uploads/2012/07/Siemens-Star-Focus-Chart.pdf
http://mansurovs.com/wp-content/uploads/2012/07/Focus-Test-Chart.pdf
http://regex.info/blog/photo-tech/focus-chart

How to Check Focus
http://photographylife.com/how-to-quickly-test-your-dslr-for-autofocus-issues
http://www.nphotomag.com/2013/03/05/how-to-recalibrate-your-nikon-dslrs-af-autofocus/
http://www.luminous-landscape.com/essays/are_your_pictures_out_of_focus.shtml
http://regex.info/blog/photo-tech/focus-chart#features
https://photographylife.com/how-to-quickly-test-your-dslr-for-autofocus-issues
https://photographylife.com/how-to-calibrate-lenses
http://www.canonrumors.com/tech-articles/this-lens-is-soft-and-other-myths/
http://cameralightlens.com/newsblog/?p=264
http://digital-photography-school.com/how-to-do-autofocus-fine-tuning-on-your-nikon-dslr/.

rdubreuil Loc: Dummer, NH USA

Have you tried pushing it all the way to -20 with any improvement? Have you also tried using the built in auto fine tune feature on the D500 to see what the camera comes up with?

nikonkelly Loc: SE Michigan

it would sound like the lens may have been dropped or just had a manufacturing defect to make it so far off. yes I would send the lens in. I had a D850 that was having issues with all lenses and so I sent it in, but had it been only one lens, then I would have sent in only the lens. just my opinion.

farwest Loc: Utah

rdubreuil wrote:

Have you tried pushing it all the way to -20 with any improvement? Have you also tried using the built in auto fine tune feature on the D500 to see what the camera comes up with?

I get an error every time I try the auto fine tune. I went through the auto fine tune procedure step by step with the camera and lens supported by sand bags to keep everything steady but it won't work.

Also have tried -20 still back focuses

What disturbs me is I sent it in and they tell me it is within specs but it is also set on the D4 to a -15 to get it dialed in.

farwest Loc: Utah

Not to my knowledge has it been dropped but it was bought used also. It disturbs me that I sent it in already to Nikon and I still have this issue. I was hoping when I bought the D500 it would be ok as the D4 back focused but they changed out the lens mounting plate on the D4 but I have it set at -15 to get decent results. I would sell the lens but not until I know for sure that it isn't the lens. So I guess I have to send it in again and see what they say.

Thanks

Bozsik Loc: Orangevale, California

farwest wrote:

Not to my knowledge has it been dropped but it was bought used also. It disturbs me that I sent it in already to Nikon and I still have this issue. I was hoping when I bought the D500 it would be ok as the D4 back focused but they changed out the lens mounting plate on the D4 but I have it set at -15 to get decent results. I would sell the lens but not until I know for sure that it isn't the lens. So I guess I have to send it in again and see what they say.

Thanks

Send it in with the camera body. Let them see if they can match the two.

Fotoartist Loc: Detroit, Michigan

I have the Nikon 300 2.8. Sharp as a tack. Not familiar with back focus.

nikonkelly Loc: SE Michigan

seriously, it is not all that uncommon that when you send something to nikon that they dont find/fix what is needed. call them, send them pictures of what it is doing and them tell them... not ask them... for a free shipping label. with the pictures and by telling them in the rma info, they should be able to fix what is wrong with the lens. I hear of all too many people who have not diagnosed their issue and told nikon what to check out, that have sent their camera or lens or both and still have not gotten the problem fixed. it is almost as if they look to see if the camera is way out of focus and if not, then it must be ok, when in reality, they should be checking for critical focus. Some of us use our cameras for very critical focus and that was what it was made for, but some of the techs seem to think that we are all just a bunch of newbies or amateurs at best.

farwest Loc: Utah

nikonkelly wrote:

seriously, it is not all that uncommon that when y... (show quote)

Thanks, it drives me crazy to see the image sharp behind where it should of focused.

farwest Loc: Utah

Thanks for a few more places to research. I have been on many of them. I have lens align for my normal lenses but if feel it is to small to use with the 300mm.