Nikkor 50mm f/1.8G on D610 - back focus issue

[8bit]

Posted this on Talk Photography forum already but thought it was worth asking here too...

Upgraded my old D5100 to a D610 last week and noticed that most of my shots at wider apertures seemed to be out of focus. I did some tests last night with the camera on the tripod, angled about 30 degrees at a piece of printed A4 paper flat on a table about a meter or so away and the camera and lens combination is consistently focussing behind the selected AF point (center in this case).

I can adjust with AF fine tune, but even at the maximum setting it's slightly better but still considerably off. It's definitely not camera shake because some text about an inch further up the page was nice and sharp but the text directly under the focus point was blurry.

The only other FX lens I have is my Sigma 105mm macro so I test that as well and it's fine. I did also test both those lenses on the old D5100, there's no adjustment there but both of them were better than the 50mm on the D610 so it seems to be an issue between the 50mm and D610 only.

What are my options here, is it the lens that might need some attention or the camera, or both? The camera was bought used from MPB.com so there's some warranty there, the lens I've had for a couple of years so I guess I'd have to foot the bill to get that sorted, if it comes to that.

[Simpo Two]

Welcome to the shallow DOF you bought an FX body for Things you never noticed before are now an issue.

I think the answer is to send them off to somewhere and get them calibrated together, but I can't suggest where as never needed to do it.

Or say 'bks' and use f4....

[8bit]

I take your point, but I did test both lenses on the D5100 as well, it's only the combination of the D610 and 50mm lens that shows the focus as being off. The difference in DoF between the two cameras with the same lens is quite significant though, for sure.

[Beggarall]

Jon Mullins found here has a very good reputation for sorting these sort of problems - suggest you give them a call

[8bit]

Beggarall said:

Jon Mullins found here has a very good reputation for sorting these sort of problems - suggest you give them a call

Thanks for that. Looking at the website though, they seem to be charging hundreds of pounds just to update camera firmware (free from the manufacturer), adjust the AF fine tuning options (available to the user in the camera's menus) and enable back-button focus. That can't be right, surely?!

[Beggarall]

8bit said:

Thanks for that. Looking at the website though, they seem to be charging hundreds of pounds just to update camera firmware (free from the manufacturer), adjust the AF fine tuning options (available to the user in the camera's menus) and enable back-button focus. That can't be right, surely?!

Have never used them myself - agree it looks expensive - it still maybe worth giving them a call and asking for an opinion/quote. They come highly recommended by others. Otherwise I think you will have to do a google search or maybe talk to your local camera shop.

[8bit]

Well if that really is all they're doing then that's bloody daylight robbery. Anyway, I bought Reikan FoCal off the recommendation of a few folks on Talk Photography (and other threads on here) and tried calibrating my lenses at the weekend. It recommended AFFT of -16 for the Nikon 50mm and -3 for my Sigma 105mm. I took the 50mm out and about yesterday, haven't had a close look at the shots yet but I guess without sending the camera and lenses away for anything more in-depth, that'll be about as good as I'll get. Will report back once I've had a look.

[steveatesh]

8bit said:

Well if that really is all they're doing then that's bloody daylight robbery. Anyway, I bought Reikan FoCal off the recommendation of a few folks on Talk Photography (and other threads on here) and tried calibrating my lenses at the weekend. It recommended AFFT of -16 for the Nikon 50mm and -3 for my Sigma 105mm. I took the 50mm out and about yesterday, haven't had a close look at the shots yet but I guess without sending the camera and lenses away for anything more in-depth, that'll be about as good as I'll get. Will report back once I've had a look.

Sorry, assuming some people on here won't understand your post, ahem, I think my friend for example ahem, could you please explain a bit more about this? Like what is AFFT and how on earth do we adjust automatic focus on a prime lens or any other lens for that matter without the presence of a screw or widget to do so?

I'm asking because I have one of these lens and I've always struggled getting really sharp images, especially at the wide open end, so much so I dare not use it in shoots which matter. I didn't know whether I have a bad copy or I'm just st at using the lens (More likely the latter) Er I mean my friend has one....

I'll be sure to tell my friend.....

[8bit]

steveatesh said:

Sorry, assuming some people on here won't understand your post, ahem, I think my friend for example ahem, could you please explain a bit more about this? Like what is AFFT and how on earth do we adjust automatic focus on a prime lens or any other lens for that matter without the presence of a screw or widget to do so?

I'm asking because I have one of these lens and I've always struggled getting really sharp images, especially at the wide open end, so much so I dare not use it in shoots which matter. I didn't know whether I have a bad copy or I'm just st at using the lens (More likely the latter) Er I mean my friend has one....

I'll be sure to tell my friend.....

So AFFT is AutoFocus Fine Tuning. It's a facility on a lot of DSLR cameras to allow for compensating for a lens which consistently front or back focuses. By that I mean the autofocus point will be placed on something (a subject's eye, to use portrait shots as an example) but the sharpest part of the subject will end up being in front of that, e.g. their nose (front focusing) or behind that, e.g. their ears (back focusing).

I noticed that my 50mm lens was doing this on my new camera, consistently focusing quite far behind, e.g. if I focused on my cat's eye from a couple of meters away at wider apertures, the fur between her ears and behind her whiskers would be much sharper than her eyes or other front features of her face.

I never really noticed this with that lens on my older camera, from what I've read it tends to be a combination of a specific lens and camera and is due (at least in part) to manufacturing variance. If you feel that a certain lens is consistently focusing either in front or behind compared to what you'd aimed the autofocus point on then you might be able to resolve it with AFFT. If your camera doesn't have that then you may be a bit stuck, though.

[steveatesh]

8bit said:

So AFFT is AutoFocus Fine Tuning. It's a facility on a lot of DSLR cameras to allow for compensating for a lens which consistently front or back focuses. By that I mean the autofocus point will be placed on something (a subject's eye, to use portrait shots as an example) but the sharpest part of the subject will end up being in front of that, e.g. their nose (front focusing) or behind that, e.g. their ears (back focusing).

I noticed that my 50mm lens was doing this on my new camera, consistently focusing quite far behind, e.g. if I focused on my cat's eye from a couple of meters away at wider apertures, the fur between her ears and behind her whiskers would be much sharper than her eyes or other front features of her face.

I never really noticed this with that lens on my older camera, from what I've read it tends to be a combination of a specific lens and camera and is due (at least in part) to manufacturing variance. If you feel that a certain lens is consistently focusing either in front or behind compared to what you'd aimed the autofocus point on then you might be able to resolve it with AFFT. If your camera doesn't have that then you may be a bit stuck, though.

Cheers for that, everyday is a school day