The GetDPI Photography Forum

Great to see you here. Join our insightful photographic forum today and start tapping into a huge wealth of photographic knowledge. Completing our simple registration process will allow you to gain access to exclusive content, add your own topics and posts, share your work and connect with other members through your own private inbox! And don’t forget to say hi!

D800/E live view vs manual focus indicator

vjbelle

Well-known member
I wanted to be able to focus a little faster while using my manual lenses and tested the accuracy of the focus indicator against live view. All of my lenses ( Zeiss 100mm, Zeiss 50mm Macro, Zeiss 35mm F2 ) focused the same way - all of them back focused. If I relied on the focus indicator the intended target was out of focus and the focus point was behind the target. I could repeat this time after time. If I focused in live view and then checked the focus indicator I found that I was just on the leading edge ( left arrow and slightly blinking focus indicator ). So, if I focused that way using the focus indicator I was able to accurately match live view..... 95% of the time. Even when I was off it was so slight that I don't think it would ever matter as I usually shoot at f 5.6 to f 8. What's even more interesting is that my Nikon 85 f 1.8 focuses very accurately with the focus indicator as long as I leave the micro adjustment activated. If I zero out the micro adjustment it exactly mimics the Zeiss lenses. This is hardly the end of the world for me but my Canon 5D II is dead on when comparing manual focus indicator vs live view. I'm quite sure that this can be adjusted by Nikon but am curious if anyone else has checked manual focus vs live view for accuracy. Could this be an accurate way of determining whether or not the camera itself has a focus issue?

FWIW I use live view with a lupe and always at f 2.8 as this provides, for me, the clearest image on the LCD.

Victor
 

Jack

Sr. Administrator
Staff member
That's totally normal behavior: Live view uses the sensor itself to determine focus, so is dead-on accurate. AF uses the AF module behind the mirror which needs to be tuned for your lenses and camera. You do this in the tool menu under AF Fine Tune -- note that it works for manual focus lenses using the AF confirm dot too. Most of my lenses back-focus on my body and need to be tuned to around minus 10 to minus 15.

Cheers,
 

Guy Mancuso

Administrator, Instructor
Same as Jack here and also on my Zeiss glass my focus confirm happens right at arrow turning to full circle. It happens right at the blink over. Now in live view this week especially with my samyang 14mm I tried opening to 2.8 from working aperture for manual focus in live view and it did not seem to be any advantage over working aperture as long as I had good light. Now I also use manual exposure most of the time and you can just open up more by dialing in a little extra exposure to brighten up live view for focusing. I find manual mode to be far nicer to work in with live view . I can also see and adjust exposure better in live view. So in effect it does two things better focusing and nailing exposure and the LCD nails them both very well. Of course doing night work live view is much harder to use but that I can deal with.
 

vjbelle

Well-known member
That's totally normal behavior: Live view uses the sensor itself to determine focus, so is dead-on accurate. AF uses the AF module behind the mirror which needs to be tuned for your lenses and camera. You do this in the tool menu under AF Fine Tune -- note that it works for manual focus lenses using the AF confirm dot too. Most of my lenses back-focus on my body and need to be tuned to around minus 10 to minus 15.

Cheers,
I would think that Nikon could make this whole system a little tighter but that probably is very wishful thinking. I'm aware how it all works regarding reading off the sensor vs the AF module and am somewhat relieved to see that you/others are also experiencing what I am seeing. I presumed that AF Fine Tune was limited to only AF lenses..... but am now aware that the DEFAULT value can be changed which would then affect my manual focus lenses and all AF lenses ( haven't tried this yet but am going to). I'm also assuming that if I change the default value that I would then have to make a compensation for any AF lenses that were fine tuned with the Default value at '0'. If the Default value is changed it would be additive/subtractive from an individual AF lens adjustment. Hope I'm making sense.....

Appreciate your pointing that out.

Victor
 

jlancasterd

Active member
I've only recently bought a 25-35-50 set of Zeiss manual-focus lenses for use on my D800(E) and have been pleasantly surprised to find how easy it is to focus these lenses (especially the 35 f2 and 50 f2) on the ground glass screen in both cameras. It isn't a particularly fast way of focussing, but it does seem to give accurate results. I'm no great fan of live view.
 

vjbelle

Well-known member
I tried adjusting the Default Fine Tune but it had no affect on my manual lenses. If it would then I would be able to live focus and check the AF Dot accuracy ( which should be a round dot ). However nothing changes...... even going all the way to -20 or +20. That is the only adjustment available when a manual lens is attached. Like I said in my original post.... not a big deal. If you know of a way to adjust the AF module for manual lenses please share.....

Thanks for your responses.

Victor
 

glenerrolrd

Workshop Member
How could this be normal ? Surely the position of the AF sensor vs Sensor has to be taken into account . Aren t we just looking at an issue of acceptable tolerances . Just as in the screen may not be exactly calibrated to show what is sharp at the sensor .

LV uses a read off the sensor ..the other methods rely on calibration accuracy .

I have got to try the default adjustment as this could help with the manual focus lenses .
 

Jack

Sr. Administrator
Staff member
It is normal. Even if the AF module is perfectly placed relative to the sensor, the communication between the AF module each individual lens focus motor is also a variable and probably very difficult to control as tightly as needed for this sensor -- a few microns one way the other and you will see it at 100%. Moreover, lenses vary between the same model and one element may be a few microns off compared to the one sitting next to it on the line and this also adds another significant variable: that difference of element positioning can change the exact focal length of the lens. The difference is very small, like one lens is really a 49.8mm lens and the other is a 50.2mm lens, but now the focus 'run' is not linear and the code for that motor is slightly off the median benchmark of 50.0mm. Finally, actual contrast at the AF module can vary based on image, and cause more issues. All of this is why Canon and Nikon give you the options to AF tune your lenses in these newer high res cameras.
 

vjbelle

Well-known member
LV uses a read off the sensor ..the other methods rely on calibration accuracy .

I have got to try the default adjustment as this could help with the manual focus lenses .
I'm in total agreement with you..... I just thought that the two methods could be tighter or the AF module adjusted so that it agrees with the sensor focus. I am convinced that the Default fine tune adjustment has no affect on manual lenses.

One other piece of info..... all of my Zeiss lenses when focusing on infinity do not give a solid round dot but rather a left arrow and blinking dot. When checked in live view things are very crisp. Again..... no big deal..... in fact it may be a blessing in disguise. The dot itself has a fair amount of play before indicating either focusing too far or too close..... too much play for me. The left arrow and just blinking dot is a very tight focus adjustment.... you gotta be really on the money to make that happen. Just so happens that this coincides with accurate focus.... at least for me. Very repeatable!

Victor
 

Jan Brittenson

Senior Subscriber Member
My focus assist also is accurate as soon as only the circle is light and the right arrow goes out. Good thing too, because the indicated in-focus range is too wide otherwise.
 

Jan Brittenson

Senior Subscriber Member
The default setting isn't additive; it's simply a value used when you have nothing else set for a lens.

I actually wish they had two defaults: one for AF, and one for non-chipped. Or a separate for AF and MF regardless of whether the lens is chipped, to permit fine tweaking when it's used solely for assist.
 

vjbelle

Well-known member
It is normal. Even if the AF module is perfectly placed relative to the sensor, the communication between the AF module each individual lens focus motor is also a variable and probably very difficult to control as tightly as needed for this sensor -- a few microns one way the other and you will see it at 100%. Moreover, lenses vary between the same model and one element may be a few microns off compared to the one sitting next to it on the line and this also adds another significant variable: that difference of element positioning can change the exact focal length of the lens. The difference is very small, like one lens is really a 49.8mm lens and the other is a 50.2mm lens, but now the focus 'run' is not linear and the code for that motor is slightly off the median benchmark of 50.0mm. Finally, actual contrast at the AF module can vary based on image, and cause more issues. All of this is why Canon and Nikon give you the options to AF tune your lenses in these newer high res cameras.
Jack,

My post had/has nothing to do with AF lenses..... only manual focus lenses. I only mentioned my 85 f1.8 (my only Nikon AF lens) because without an AF fine tune it exactly mimicked my Zeiss lenses.... same back focus and same left arrow and blinking dot when in focus with live view. So the question still goes begging.... is this a way to determine whether or not the camera itself has a mis-aligned AF module? If so then Nikon could Zero in the AF module and more than likely I wouldn't have to make a -12 adjustment for my 85 1.8 and all of my manual focus lenses would be in the center of the focus assist dot when in focus. Make sense?

Victor
 

Guy Mancuso

Administrator, Instructor
My focus assist also is accurate as soon as only the circle is light and the right arrow goes out. Good thing too, because the indicated in-focus range is too wide otherwise.
Exactly why I like it. It's actually more accurate because the circle illumination goes too deep in the focus. I like the quick blink knowing I am hitting it.
 

Guy Mancuso

Administrator, Instructor
Jack,

My post had/has nothing to do with AF lenses..... only manual focus lenses. I only mentioned my 85 f1.8 (my only Nikon AF lens) because without an AF fine tune it exactly mimicked my Zeiss lenses.... same back focus and same left arrow and blinking dot when in focus with live view. So the question still goes begging.... is this a way to determine whether or not the camera itself has a mis-aligned AF module? If so then Nikon could Zero in the AF module and more than likely I wouldn't have to make a -12 adjustment for my 85 1.8 and all of my manual focus lenses would be in the center of the focus assist dot when in focus. Make sense?

Victor
If I'm reading you right than this would be hard to do. Sensors could be slightly diffrent from one body to the next and even 2 50mm lens could read diffrent off the same sensor. This is why they put in the AF adjust , now the question is it better at full circle illumination or just as you hit the circle. Depends on user I guess but I think you can move the default to do that with manual glass. It's not a easy task as it is a very narrow gap to hit full illumination from just the arrow switch. I think you actually have to adjust each lens to hit full illumination . I have not bothered to try that. I guess knowing that on all three manual lenses hit at the same point is good enough even though its at the change from arrow to full circle and as Jan said that full circle is deep in focus and honestly would throw you off. Simply don't know when to stop
 

glenerrolrd

Workshop Member
While the discussion of AF adjustments has a bearing on the question of MF ..it seems to confuse the issue . Given that Nikon and Canon built in AF adjustments to account for variations in individual lenses . This was widely discussed when they did this because up until this time ..lenses were sent back to Nikon if they were individually off .

So maybe we could stay on the MF lenses. The AF system was clearly designed to provide an accurate focus point without need for an adjustment . It is absolutely true that its not uncommon to find some variation in bodies like the D800 ...this is a calibration error . (I don t consider this normal but its semantics and not important ......we agree it happens frequently). Similar to when the image off the mirror focuses at a different point than the image that is on the sensor .

My experience with the D3s,X and D4 is that the professional bodies are made to tighter tolerances ...only anecdotal evidence but I ve had better experience with MF on the Pro bodies).

What has been lost in this thread is the statement that you can make a Default adjustment on a body . This would first calibrate the body ..by bringing the on sensor and AF points into alignment .(not an adjustment for the AF of a specific lens) . I can tell you I looked for exactly this capability on the D3X and the D800 ...so I am excited to find that I might have a solution for the manual focus zeiss lenses.
 

glenerrolrd

Workshop Member
It looks like the default setting works with manual focus lenses that are chipped ...AI P . Not positive but this would explain why the the Zeiss ZF lenses didn t adjust and the ZF.2 appear to work . You can chip the Leitax mounts for the R lenses.
 

vjbelle

Well-known member
My lenses are not chipped..... the Default setting doesn't work for me. However since this may be a camera global setting that setting would also influence individual AF lens micro adjustment settings. Any Default setting would become additive or subtractive.
 

glenerrolrd

Workshop Member
My lenses are not chipped..... the Default setting doesn't work for me. However since this may be a camera global setting that setting would also influence individual AF lens micro adjustment settings. Any Default setting would become additive or subtractive.
From Thom Hogan s manual on the D800 .....the default setting does not affect individual lens adjustments ...its either default or a specific setting by lens.

This looks to be a good solution for AI P (chipped) lenses.
 
Top