Nikon D800 auto focus

JayceeC

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John
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I was having a auto focus issue with my camera despite the lens that was attched. After a bit of research I decided to but a sensor cleaning kit. After watching a few youtube vids on cleaning I locked the mirror up for cleaning, was having a look at the inside and put it back together. Since then it hasn't missed a beat and the focussing on the 50mm lens is very quick, hopefuly it will stay that way.

Just wondering weather to clean the sensor when the kit comes if it is still working fine.
 
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Dust on the sensor shouldn't affect autofocus. If the sensor is dusty then you'll see small dark specks all over the image when you're stopped down.
 
I found that on the 800 that I had, the focus was very dependent on having a good contrast. It hated focussing on dark or low contrast images.

Maybe your 'problem' is/was related to this? :thinking:
 
I hoped in that kit is included a"Loupe". I no longer have that camera (the D810 I also had was a lot better). Whatever you do Don't ever ever never use a rocket blower you will make matters much worse.

my sensor cleaning kit now for mft cameras

Top Artic butterfly and" Loupe best thing (essential in my opinion) you can have for sensor cleaning"
below cleaning fluid and swabs and rocket blower
Du00EGjm.jpg


Can I please pass you on a tip I learn't from cleaning my camera sensors over many years. If your going to use cleaning fluid with a swab, don't pour the fluid over the swab you will flood the sensor. NO what to do is put a drop of fluid onto a clean surface and dip the swap onto it. That way you limit the amount needed on the sensor.

Don't try and rush the job, take time and be gentle, it may take several wipes to get rid of stubbon dirt so check after each wipe preferrably with a clen swap
 
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We have different techniques. I find a blower useful, and (as directed by the maker) I put a drop of cleaning fluid on the swab.

Probably best to follow the instructions of the kit you bought for the first clean.
 
Whatever you do Don't ever ever never use a rocket blower you will make matters much worse.
Actually, a bulb blower is probably exactly what John would have needed. It's almost certain that the issue with autofocus was due to something on/blocking the AF module's field lens in the bottom of the mirror box; and not due to a dirty image sensor.


Just wondering weather to clean the sensor when the kit comes if it is still working fine.
Personally, I don't clean the sensor unless it really needs it (i.e. when editing out sensor spots becomes annoying).
 
Thanks for the reply guys, I took the camera out today with a different lens and it worked fine, the kit hasn't arrived yet so I will hold off for a while.

It would get really close to focusing but would not beep, and would not take a pic until the focus ring was turned and the resulting picture looked under exposed.

Perhaps the movement from locking the mirror dislodged some particle of debris.
 
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I got a similar cleaning kit to @realspeed, I used the blower and followed the instructions that came with it. That seemed to do the trick but the problem re-appeared.
I seem to remember that the camera hadn't been used for a few years so I gave the sensor two more passes with the cleaning fluid. I have taken 50 plus test pics without issue so hopefully problem is sorted.
 
take an image at f/16 or f/32 against a white wall and you will see any dust on the sensor

no need to focus...... just take the image and process it
 
An old saying:- If it ain't broke, don't fix it. The hand held blower is ideal if you have to do anything, together with a VERY
soft lens brush that is used for this job and no other.
 
Have you tried cleaning the electrical contacts on the camera and the specific lens?
 
Thanks for the comments guys, the contact cleaner will be my next task, it worked with the hot shoe flash
 
Well I cleaned the sensor twice more and it has worked ever since, thats is about 200 actuations
 
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