Testing D800 for left focus issue

Cheers Martin. Not much doubt that there is something wrong there! I tested mine today using my 24-70 and it appears that all is fine. Zooming right in very very close there is a very slight difference between the LV and normal focus shots, but it's nothing like what you have here.

Have to admit that I had no idea until doing this that LV focused in a different way, and I still can't quite get my head around it....
 
psybear said:
Cheers Martin. Not much doubt that there is something wrong there! I tested mine today using my 24-70 and it appears that all is fine. Zooming right in very very close there is a very slight difference between the LV and normal focus shots, but it's nothing like what you have here.

Have to admit that I had no idea until doing this that LV focused in a different way, and I still can't quite get my head around it....
Click to expand...

No problem. Yes it was all news to me as well and the info in this thread was invaluable. Glad yours passed the test. If you didn't use mirror lock up when shooting through the view finder that could've contributed to a small difference to your result with live view. Although slight, the mirror locking up causes a tiny bit of camera shake which would effect the quality. From the examples I have seen then I think its plainly obvious if there is an issue. We can now just get on with enjoying what is a fantastic camera. :-)
 
the_local_jacko said:
As requested, I have re-uploaded the images as below :

Shot taken with left focus point :


Left Focus Issue by the_local_jacko, on Flickr

Shot taken with live view focus in the exact same position :


Live View Shot by the_local_jacko, on Flickr
Click to expand...

Are those differences typical of the left focus issue?

I've been checking mine but obsessing over what could be a couple of pixels worth of difference wondering whether there was an issue, looking here this is a very significant change and I may be wasting my time....
 
Yes, from my research online the differences are pretty obvious, you generally dont need a chart/m-up/tripop or even LV to test for it, just shoot wide open at extreme AF points. The edge points will always be very slightly softer than the center.
 
I dont think it had to be as bad as above.. mine wasn't as bad as that but was still noticeably softer than the centre or right side.

If you do send it in make sure you are prepared for any issues, thats mine going back for a second time with all my lenses to be calibrated together.

I also had a Pm via another forum from a guy thats had his back this week with exactly the same issue..
 
pmac do you have any samples of what yours was like? Sounds like you both ended up with the same technician.
 
Thanks for the thoughts. I'm thinking if I'm having to look this closely and I'm still uncertain I've got an issue then I'm probably one of the lucky ones who hasn't. I don't like the thought of sending it off to have it come back worse. I feel for you guys having this issue, very disappointing with a camera this expensive.
 
Matt-P said:
Are those differences typical of the left focus issue?

I've been checking mine but obsessing over what could be a couple of pixels worth of difference wondering whether there was an issue, looking here this is a very significant change and I may be wasting my time....
Click to expand...

From the examples I've seen then that is a typical example of specific left AF issue. If you see the you tube link that was posted further up this thread then you can see similar results. There are many others unaffected by left AF issue that have had to adjust the AF in the fine tune menu setting for some if their lenses. This has been put down as a factor from the large sensor size meaning that any tiny AF inaccuracy is gleamingly obvious. It may be that its just this adjustment that is needed in your case. I would go with swifts suggestion and if it will put your mind at rest then post some samples and get opinions from others.
 
If I get some child free time this weekend I'll post a couple up. Tips like locking the mirror up may help at little but preventing a 2 year old swinging from the tripod will have a far greater benefit!!
 
Put a book upright..... I used the D800 manual.

1) Set camera to AFS, center point, widest aperture, defocus lens, take photo after confirmation beep.
2) Move center point to left point, defocus lens, take photo after confirmation beep.
3) Zoom in with LCD or Lightroom 1:1
4) If only slightly worse than center point theres nothing to worry about.

10 mins tops. DONE.
 
Last edited:
If there is a need for you to use a focus target then below is a good place to get hold of them. As twist suggests a book will work fine and is easier however.

http://www.image-engineering.de/index.php?option=com_content&view=article&id=373&Itemid=163

As a bit if an aside, I took a shot of my front room when i was playing around with the D800 the other day and there was a magazine just sitting on a chair in the shot around 11-12 foot away from camera position. On it was a barcode around 1.5 inches square with a number under it that was probably in font 8. There's no way you could make out that that it was text with the naked eye let alone read it but if I zoomed on the image you could read the text clear as day. The detail in the D800 images is just mind blowing.
 
You must log in or register to reply here.
Back
Top