Focus Issues
Jul 22, 2020 10:53:25 #
I have a Nikon D750. My Tamron 45mm 1.8 works flawlessly in auto focus. I tried to manual focus using the focus dot and the photos are all in focus so I know the camera is working properly.
I bought a mint condition Nikkor 300mm 4.5 manual focus lens. I setup the lens in NON-CPU and the aperture reads correctly when changed on the lens. So I went out to test the lens. I took 135 photos, taking photos only when I got a solid white dot. Well, all 135 photos are out of focus. Not some, ALL. I have tried close and distance. The white dot seems to mean nothing with this lens. Is this a defective lens or is this lens simply not compatible with the D750? It is in mint condition however it is about 50 years old.
Any suggestions?
I bought a mint condition Nikkor 300mm 4.5 manual focus lens. I setup the lens in NON-CPU and the aperture reads correctly when changed on the lens. So I went out to test the lens. I took 135 photos, taking photos only when I got a solid white dot. Well, all 135 photos are out of focus. Not some, ALL. I have tried close and distance. The white dot seems to mean nothing with this lens. Is this a defective lens or is this lens simply not compatible with the D750? It is in mint condition however it is about 50 years old.
Any suggestions?
Jul 22, 2020 11:16:24 #
Yes, a few thoughts:
1. Why not just manually focus the lens onto the subject as best you can? Watching a dot in the corner of the view finder can't be any more efficient than just focusing on the actual subject with your eyes via the view finder.
2. Why not use the back camera LCD in Live View and manually focus on the subject as best you can via the 10x zoom of the display?
3. Why not mount to a mirrorless camera and use the EVF in the 10x zoom and focus on the subject as best you can?
4. What aperture are you using, older lenses rarely look good wide open. What did your results look like at say f/8 and f/11?
5. Why are you wasting your time with manual focus lenses if you want autofocus confirmation?
1. Why not just manually focus the lens onto the subject as best you can? Watching a dot in the corner of the view finder can't be any more efficient than just focusing on the actual subject with your eyes via the view finder.
2. Why not use the back camera LCD in Live View and manually focus on the subject as best you can via the 10x zoom of the display?
3. Why not mount to a mirrorless camera and use the EVF in the 10x zoom and focus on the subject as best you can?
4. What aperture are you using, older lenses rarely look good wide open. What did your results look like at say f/8 and f/11?
5. Why are you wasting your time with manual focus lenses if you want autofocus confirmation?
Jul 22, 2020 11:18:12 #
Jul 22, 2020 11:37:39 #
Jul 22, 2020 11:50:52 #
Jul 22, 2020 11:53:19 #
authorizeduser wrote:
I have a Nikon D750. My Tamron 45mm 1.8 works fla... (show quote)
Post a sample image. Use the "store original" checkbox.
Jul 22, 2020 15:40:03 #
I used to have that lens. I had problems getting good focus too sometimes but I focused with visual acuity rather than the focus dot in the view finder. I used mine with the smallest f stop possible for a good exposure for good DOF but still had a lot of poorly focused images. I gave it to my sister-in-law along with a pretty new D 7100 when I upgraded to full frame. She uses it and likes it.
Jul 22, 2020 18:51:38 #
I returned the Nikkor 300mm 4.5 Ai lens for a refund since it turned out to be more trouble than it was worth. Since I already have a Tamron 45mm 1.8, and love it, I decided to buy another Tamron. Bought a brand new Tamron 70-200 2.8 Di VC USB G2 lens. Now all photos are crisp and in focus. No, it is not 300mm but then what good is 300mm if it will not focus. Got a 6 year warranty to boot. I am happy ................ 
Jul 23, 2020 07:47:51 #
Are you sure it isn't camera shake? What shutter speed did you use? Maybe post an example image?
Jul 23, 2020 09:22:44 #
wingclui44
Loc: CT USA
authorizeduser wrote:
I have a Nikon D750. My Tamron 45mm 1.8 works fla... (show quote)
I think you have to set where the focus point you what in the view finder of your camera, when you manually focus your MF lens at the same focus point, then the camera will confirm the focus is correct. Just set it with single focus point.
Jul 23, 2020 09:26:03 #
David Taylor wrote:
Are you sure it isn't camera shake? What shutter speed did you use? Maybe post an example image?
Exactly 300mm, you need a tripod. It’s true though that older glasses are not sharp enough for modern cameras, it’s the character of these old lenses that matter and in that case some softness is welcomed!
Jul 23, 2020 11:07:03 #
My experience with the focus dot on Nikon camera bodies is that it rarely gives you accurate focus at the same spot in the image that you had intended. I gave up on it years ago with my manual focus Nikon tele lenses and just focused them manually. That way I got the spot in focus that I was intending to get.
Today I would check focus on the LCD screen using the magnification feature. Or use Live View when appropriate. There is a custom setting you can set to magnify it so it is quick and easy.
With many of the Nikon tele lenses, they are designed to be shot wide open. The sharpest aperture may be the widest one available on the lens.
The same thing also applies to AF tele lenses. Sometimes to get the most accurate focus point, you tweak the focus manually after you get your shot taken with AF set.
Today I would check focus on the LCD screen using the magnification feature. Or use Live View when appropriate. There is a custom setting you can set to magnify it so it is quick and easy.
With many of the Nikon tele lenses, they are designed to be shot wide open. The sharpest aperture may be the widest one available on the lens.
The same thing also applies to AF tele lenses. Sometimes to get the most accurate focus point, you tweak the focus manually after you get your shot taken with AF set.
Jul 23, 2020 17:14:47 #
vbhargava
Loc: San Diego
The dot focus has a range where it stays solid. Try using the dot tune method to fine tune your lens/ camera. I just did this for all my lenses and D750. My photos are sharp.
Jul 24, 2020 05:40:34 #
D-lenses on my Nikon 7000 was problem. Other lenses worked Ok. On my 810 the D lenses are workingWithout any issue. Later I read the reviews about the 7000 where it’s shows that is a known problem, even if this body was send to fixed it’s an ongoing problem.
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