Pistnbroke
Active member
Even if steve cannot make his mind up this steve knows where his head is.
Is a Fine tune setting of +18, +20 mean a lens is defective?
- Thread starter blong10
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blong10
Member
I haven't got my Tap in console yet but I noticed something odd. When I use the viewfinder it's front focusing and when using the live view it's back focusing lol Is this normal??
For example at 70mm F 2.8 with +19 fine tune it's perfect in the viewfinder however with live view it's back focusing. I also noticed when I move further away at 70mm it will back focus however, if I get closer it will be ok. Am I doing something wrong or does this definitely suggest someone has values in the lens and until I get the console hopefully Monday I can't fix this
For example at 70mm F 2.8 with +19 fine tune it's perfect in the viewfinder however with live view it's back focusing. I also noticed when I move further away at 70mm it will back focus however, if I get closer it will be ok. Am I doing something wrong or does this definitely suggest someone has values in the lens and until I get the console hopefully Monday I can't fix this
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In Live View it shouldn't front or back focus - AFFT values aren't used one way or the other. CDAF (live view focus) focuses by turning the focus ring back and forth until it achieves maximum contrast. Even if the lens had a value set, it shouldn't matter since that's not what's determining focus in LV. It almost sounds like technique, but I can't really imagine too many reasons why - are you focusing on a flat or slanted target? A slanted target will cause weirdness like this.
blong10
Member
I'm using a Datacolor Spyderlens Cal
https://www.amazon.com/gp/product/B0041L3JS4/?tag=backcogaller-20
I tested it on another lens 35 1.8 and I don't have this issue. I have my D850 on a tripod and the Spyderlens on another tripod as well
with a fine tune value of 0 in live view, it's perfect (tested with 70mm) but with the view finder it's front focusing around 6. I then have to dial in +19 to make it way better
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That is odd - that's a good target for it. Is the target well lit? Normally, something like that should be perfect in LV. I just don't see how any AFFT settings in the lens would matter based on how LV works, but I've not dealt with lenses like that before so there could be a piece of the puzzle I'm unaware of. At this point, probably best to play with it with the console tomorrow and see.
One other thought, keeping in mind I'm not an optical engineer or anything remotely resembling one. Is the target sharp under the AF area where you focused? Also, is that area sharper or as sharp (or not as sharp) and the rest of the target? I almost wonder if there's a lens element that's slightly tipped or something. You may want to try turning the camera vertically and see if the results are the same.
Still, I'd probably wait and see what happens with the console before anything else.
blong10
Member
I'm going to wait until the console comes in as I can then work with a clean slate after I reset the lens. I'll definitely keep you all posted. Thanks everyone
blong10
Member
Sorry for the delay. I was able to update the Lens and reset it back to factory settings. I now require only a +4 HOWEVER I'm having a strange issue now. At 70mm 2.8 at almost infinity, I'm getting extremely soft images in Live View but not the view finder. When I move closer I get better shots in LV . Here comes some more weirds issues. If I turn the camera horizontal at the same focal length and distance the picture is sharper not by a lot but noticeable. I have to stop down to 3.2 to get a sharp picture at 70mm 2.8 in Live View I'm using a tripod and a shutter delay. Is something wrong with my camera? or is more or less the lens.
That is weird. All I can say is I had a similar problem with the Nikon 80-400. Lv focus was really poor. Didn't make any sense, but when I focused it manually in LV, it was fine. In fact, I'v had people comment on some of my older tests that included that lens and they were surprised how well it fared against my other optics, especially when compared to what they had heard from other tests. Since most lens tests are done using LV (it's usually better) I have a feeling my 80-400 wasn't the only copy that behaved that way!
In any event, at this point if you can still return it, I think that might be the way to go. For me, it's to the point where I just wouldn't be able to trust the lens. Anytime I have a piece of gear I don't trust completely, it's out the door. It seems to me like you've done everything within reason - and then some. I'd go for another lens.
blong10
Member
Thanks Steve! I think that's the best option. I'm going to purchase a nikon 24-70 VR once I get my money back. If I do manually focus on live view using and using the focus peaking it's dead on. So does that also help some? I'm just praying it's not my d850
Pistnbroke
Active member
You did not say if you did a full input of all the setting points required by the doc or just did a setting at max focal length. If you only did it at full length that could be your problem
blong10
Member
Sorry, After I reset the lens I did a full calibration at every focal length and at 70mm at infinity it was way off in live view but could be fixed if I stop down to 3.2 but in the view finder it was ok at 2.8. I just tested my DX 35mm 1.8 lens and I don't seem to have this issue by the small tests I've done in dx mode. Live view matches what the view finder does. Also I found it odd if I put the 24-70 lens vertical it was better. It seem like something is not aligned in the lens correctly
Pistnbroke
Active member
What you are saying does not make sense to me ..I assume you are using the auto fine focus adjust on your D850 to get the figures ?? You should have your camera at zero and all the offsets in the lens.
I have posted the figures for my two T 100-400 which look like total madness but they work perfectly. If you or steve want me to do a post on how to do this let me know.
I have posted the figures for my two T 100-400 which look like total madness but they work perfectly. If you or steve want me to do a post on how to do this let me know.
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blong10
Member
Yep, I have done that already. Started at a perfect 0 on all my adjustments. I used the Spydercal to make sure all was right but adding + and - at every focal length until it's a dead zero on my calibration tool. It is the oddest problem ever. It's ok in the viewfinder after taking the picture but off in live view until I stop down to 3.2 then it's good. My other lens doesn't do this or behave this way. But if I turn the 24-70 sideways it's perfect at 70mm 2.8. I must have got a bad copy. And I've been playing with this lens for about a week and getting nowhere.
Pistnbroke
Active member
Well I would not be using spydercal when you have auto fine tune in the camera. Its certainly not big enough to use at 60 yards ..infinity. Have you upped the sharpness in picture control as this sharpens the rear lcd but does not affect RAW. I suggest +9