Focus not sharp.

john*thomas

Senior Member
I have a D7100. My focus is not sharp. Soft I guess. Did I do something? LOL....I know I on occasion hit things I didn't mean to. What's the best way to check this? I've got nothing saved....can I just reset the settings? (I believe I've seen people suggest this).

DSC_5170-20150904 (800x576).jpg

Now this is my Tamron 70-200 2.8. Before I could see extreme detail of a bird. I bought this lens as a refurbished and thought maybe whatever was the reason for original return, returned. I have approval to send it back but then I thought I should make sure it's the lens.

I put on my Sigma 18-250 3.5-6.3. Maybe I'm just not sure but it doesn't seem as sharp as it was either.

DSC_5174-20150904 (584x800).jpg

Where should I start?
 

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Horoscope Fish

Senior Member
It's hard to be 100% certain but it appears to me you MIGHT have a little front-focusing going on in the bird shot. Notice how the screw-head and tail feathers appear sharper than the bird's head? That's what I'm basing my suspicion on. It's not a lot to go on (your images are 600 x 400 so they don't resize well) and I could very well be wrong but have you checked/calibrated your lenses for front/back focus?

Also, is your Tamron 70-20mm the later version, the one with VC?
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john*thomas

Senior Member
It's hard to be 100% certain but it appears to me you MIGHT have a little front-focusing going on in the bird shot. Notice how the screw-head and tail feathers appear sharper than the bird's head? That's what I'm basing my suspicion on. It's not a lot to go on (your images are 600 x 400 so they don't resize well) and I could very well be wrong but have you checked/calibrated your lenses for front/back focus?

Also, is your Tamron 70-20mm the later version, the one with VC?
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I can take other pics and resize to whatever is needed. It is the older one but it was super sharp. I've never calibrated squat before. LOL

Isn't a calibration lens specific?
 

Fred Kingston

Senior Member
Yes...it is lens specific... Your lens is focusing fine, in my opinion. It's just NOT focusing where you want it to... Nikon has a Fine Focusing feature in your camera, realizing that manufacturing tolerances are greater than what the consumer wants, the Fine focusing feature allows you to adjust and compensate for those tolerances... If you google "Fine Focusing D7100" you'll get dozens of videos that walk you through the various ways to correct and fine tune the focus for that lens.

Sending the lens back may or may NOT resolve your problem.
 

john*thomas

Senior Member
Yes...it is lens specific... Your lens is focusing fine, in my opinion. It's just NOT focusing where you want it to... Nikon has a Fine Focusing feature in your camera, realizing that manufacturing tolerances are greater than what the consumer wants, the Fine focusing feature allows you to adjust and compensate for those tolerances... If you google "Fine Focusing D7100" you'll get dozens of videos that walk you through the various ways to correct and fine tune the focus for that lens.

Sending the lens back may or may NOT resolve your problem.

Right......I'll do that and follow instructions before sending anything back. As I said, I do not believe my other lens is focusing correct either. (second pic above).
 

Horoscope Fish

Senior Member
I can take other pics and resize to whatever is needed. It is the older one but it was super sharp. I've never calibrated squat before. LOL

Isn't a calibration lens specific?
Well first off, if you haven't calibrated your lenses I would strongly suggest you do so.

For a quick and dirty test you could shoot some test shots of a looong expanse of a tape measure on the floor. Be far enough away you can see a couple feet of the tape measure in the viewfinder. Use a tripod, ISO 100 and put the lens at the widest aperture. Then, very specifically focus the camera on a specific number, say the 36" mark, and take your shot. If the 30" mark looks sharper in you photo, you know you've got a front-focus issue. If the 41" mark looks sharper, you know you've got a back-focus situation.

The above steps are just a quick test but to do a PROPER test/calibration for this you'll need to be more precise. There are several methods but the simplest method is probably THIS ONE found on the Nikon Europe website.

Another popular route is the Dot Tune Method (link goes to YouTube vid) or you can invest in a software based solution like Reikan FoCal.

Lastly, and before I forget... Yes, lens calibration is specific to the lens/body combination.
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john*thomas

Senior Member
O.K.....I can be a little slow and dense....lol, but I focused directly on the center battery. It appears here the focused ended up back focused. Should I do this for multiple focus lengths?

DSC_5178-20150904 (1280x852).jpg
 

john*thomas

Senior Member
Well first off, if you haven't calibrated your lenses I would strongly suggest you do so.

For a quick and dirty test you could shoot some test shots of a looong expanse of a tape measure on the floor. Be far enough away you can see a couple feet of the tape measure in the viewfinder. Use a tripod, ISO 100 and put the lens at the widest aperture. Then, very specifically focus the camera on a specific number, say the 36" mark, and take your shot. If the 30" mark looks sharper in you photo, you know you've got a front-focus issue. If the 41" mark looks sharper, you know you've got a back-focus situation.

The above steps are just a quick test but to do a PROPER test/calibration for this you'll need to be more precise. There are several methods but the simplest method is probably THIS ONE found on the Nikon Europe website.

Another popular route is the Dot Tune Method (link goes to YouTube vid) or you can invest in a software based solution like Reikan FoCal.

Lastly, and before I forget... Yes, lens calibration is specific to the lens/body combination.
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THANKS!!. I'll get more specific and do all my lens if that is what needs done, but any idea why all of a sudden things would go out of focus?
 

Horoscope Fish

Senior Member
O.K.....I can be a little slow and dense....lol, but I focused directly on the center battery. It appears here the focused ended up back focused. Should I do this for multiple focus lengths?

View attachment 178099
I agree. That shot is clearly back-focused. I would adjust that lens to about a -7 and see where that get's you.

To be thorough, yes; you should test at both the minimum and maximum focal lengths. Hopefully things won't go massively sideways on you... They could, but they shouldn't.

As for why this is happening... I could spout all sorts of conjecture but in the final analysis I'd say, "Because s--t happens."
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john*thomas

Senior Member
I can handle "stuff happens"...I got a slap for cussing earlier. LOL

Obviously I went too far with -7 and I understand this concept and how I need to do this under controlled settings (obviously the camera has moved) but how does the focused part look out there? I have an older laptop that isn't the best as far as screen resolution goes. Sometimes my pics look so-so but I get on a different computer and they look far better. (I have a better computer, the laptop is just far more convenient)

DSC_5179-20150904 (1280x852).jpg
 

Horoscope Fish

Senior Member
Obviously I went too far with -7 and I understand this concept and how I need to do this under controlled settings (obviously the camera has moved) but how does the focused part look out there? I have an older laptop that isn't the best as far as screen resolution goes. Sometimes my pics look so-so but I get on a different computer and they look far better. (I have a better computer, the laptop is just far more convenient)

View attachment 178100
The in-focus part of that shot looks very good. So that's good news, the lens *IS* taking sharp shots, you just need to get the Auto-focus dialed in.

Focus calibration in a bit of a pain in my opinion but the better the camera, and the better the glass, the more it needs to be done. It'll all be worth it in the long run.

Question, though... Are you shooting RAW or JPG? If you shoot JPG have you adjusted the Sharpness setting in the Picture Controls menu?
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john*thomas

Senior Member
I went -4....looks like I need to go -5, take some pics....see how they turn out and then go through all of this correctly with all of my lens. (Shooting Raw). I made no adjustments when I converted to JPG.

DSC_5180-20150904 (1280x852).jpg
 

Horoscope Fish

Senior Member
I went -4....looks like I need to go -5, take some pics....see how they turn out and then go through all of this correctly with all of my lens. (Shooting Raw). I made no adjustments when I converted to JPG.

View attachment 178101
That's a big improvement, and looking pretty spot on, I'd say... ^^^

Since that's an unsharpened RAW/straight to JPG image, I'd think a light touch of sharpening would really make it pop.

I'd suggest getting the AF dialed in at one specific focal length and then see if that adjustment looks just as good at other focal lengths.

Are you having fun yet? . :D

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john*thomas

Senior Member
Thanks......Here is -5.

DSC_5181-20150904 (1280x852).jpg

Yeah, absolutely no sharpening or adjustments.

How we looking?

DSC_5182-20150904 (1280x996).jpg

If this is all I have to do......I can probably handle it. LOL.

Thanks. (I'd still like to know what made things go off) :p
 

Horoscope Fish

Senior Member
Thanks......Here is -5.

Yeah, absolutely no sharpening or adjustments. ... How we looking? If this is all I have to do... I can probably handle it. LOL.

Thanks. (I'd still like to know what made things go off) :p
I think those images are looking quite good. The final decision has to be yours of course since I'm looking at significantly reduced images, but clearly you have the process nailed down. The rest is details.
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