greg14

I have a D750 and shoot 90% manual with Back Button Focus.
I vary my focus settings from 1 to 51 to Group depending on the situation or importance of the shot, at my age I keep the speed at 160-200, with or without a flash.
I have always kept the Focus Lock in the lock position.

While I like the idea of the tilt screen, it requires shooting in Live View.
For some reason my shots often appear blurry or focused wrong.

Either I am moving the camera too soon after I press the shutter button (delayed shutter) or I am not understanding the how to focus in Live View.

Any suggestions, website, you tube or answers would help.


Thanks,

FidlurJohn Loc: Paradise, Nevada 89121

Have had the same type of problem with live view on my D3300. The photos come out a bit distorted at times.

CO

When using the viewfinder, the camera is using its phase detection autofocus. In live view mode, the camera is using its contrast detection autofocus. Contrast detection autofocus is slower than phase detection autofocus. I wonder if you're giving it enough time to acquire focus. Try taking the same shots using the viewfinder and also in live view mode. Compare the images to see if there's a difference.

If the shots are blurry it could be due to camera shake or you may be jabbing the shutter button and causing shake.

greg14

I agree about camera shake, that is why I generally have the speed at 200, my primes are 28, 50 and 85, all 1.8mm.
I am thinking that the delay in the mirror release may cause a movement of the camera.

As I siad I rarely use it, but I will do some trail and error shots.

Thanks,

Greg

OnDSnap Loc: NE New Jersey

Keep in mind also, when using the viewfinder your camera is mashed against your head helping to steady it, (3 points of support) when shooting live view you loose the head as a steadying aid. (that's if your out of focus shots are in fact due to movement) You might try live view from a tripod, see if that helps or eliminates the issue.

jerryc41 Loc: Catskill Mts of NY

I can't imagine trying to focus manually in Live View. Trust Auto Focus in that situation. I find the flip-up LCD very handy for low level shots. Of course, one level of steadying (your head) is removed when using Live View.

mborn Loc: Massachusetts

in live view zoom in on the screen and focus manually

skh1454

I would add that the settings you list pertain to the PDAF system; the CDAF system is entirely independent and has its own settings. When you switch to LV, you can see your CDAF focus settings at the top center of the LV screen. If you have not changed them, it will likely be in "AF-S, Norm" - if you are shooting moving subjects in AF-S, that would account for your blur. You can change these settings the same way you change your PDAF settings, except you do it in LV mode (ie, press your focus button on the AF/M switch while rotating the Command and Subcommand dials; for the D3300 owner, I believe you press the "i" button while in LV). For moving subjects, you will need to be in AF-F (although your VF's PDAF system is far better for moving subjects). The CDAF system is somewhat limited in its ability to track moving targets. If you are shooting stationary scenes, then the problem is something else. As CO suggests, you may need to allow the CDAF more time to acquire focus; it will often overshoot the focus point and then come back. Nikon CDAF systems operate in focus priority for both AF-S and AF-F in LV to prevent this, but your BBAF set-up effectively overrides it. Camera shake is also possible, especially if you are using a longer lens (eg 150mm+) and have unsteady hands.

FidlurJohn Loc: Paradise, Nevada 89121

Thank you co!

FidlurJohn Loc: Paradise, Nevada 89121

Thank you 1454!

greg14

(1)
Thanks for letting me know that in Live View, the settings are different, as I said I rarely use it and did not bother to read the manual, Bad !
I reset it to AF-F and face detection.
(2)
What about the focus points, I see there is only the square box ?
(3)
It does have the same metering as the viewfinder
(4)
Please educate me :
CDAF, PDAF,

Thanks again,
Greg

CO

CDAF is contrast detection autofocus. When your camera is in live view mode, the reflex mirror is flipped up. The camera will adjust the focus until it achieves the highest contrast at the sensor.

PDAF is phase detection autofocus. The reflex mirror is down. A small amount of the incoming light is directed to autofocus sensors in the bottom of the camera. It's faster than contrast detection autofocus but is error prone. All of the components must be precisely aligned.

skh1454

Per CO's earlier comment, your ViewFinder (VF) uses Phase Detection AF (PDAF) while LV uses Contrast Detection AF (CDAF). PDAF is extremely fast and quite accurate, CDAF is slower but is generally capable of even sharper focus than PDAF. The PDAF system is used when the mirror is down for the VF, and some of the light is diverted to the PDAF array located in the camera body separate from the sensor. It is the PDAF system that has the 51 focus points.

In LV, the mirror flips up and the light from the lens is directed to the sensor. The PDAF system is then offline and the CDAF system takes over with hundreds of focus points located across the entire sensor surface. Yes - the area modes consist of Normal and Wide, the latter being a larger "box". If you unlock your Focus Selector, you can move the box anywhere on the screen -- you are not limited to the more centrally located PDAF focus points.

For a brief explanation on how the two systems work, here is a youtube video -- somewhat geeky but a pretty good explanation of the two systems from about 1:00 to 2:25: https://www.slrlounge.com/primer-phase-detection-autofocus-vs-contrast-detection/

Personally, I don't use LV very often but I do find it useful in special circumstances and for stationary shots where I need razor sharp focus and have the time to attain it (portraits, landscapes). I will normally use a tripod, set the camera at AF-S/Normal, move the focus box to my focus target and then use my BBAF to attain focus. I will often check the focus box by zooming in, and if necessary may switch to manual focus to fine tune it (although that is rarely required). I then use a cable release to minimize vibration. I don't use LV for moving subjects (I consider AF-F to be primarily for shooting videos) -- the PDAF system is much better at tracking action.

Hope that helps!

whitewolfowner

My guess would that you experiencing camera shake when taking the shot. These live view screens defy every rule of holding a camera for shake free usage; my biggest pet peeve about them. To use them, you have to hold the camera away off your body; so all support is lost for steadying the camera. The flip screens are intended for being able to see when you can't use the prism for framing, like over your head or down low on the ground. And of course when doing video.