[mhsp1948]

A YOUNG EAGLE Learning To Fly - By Mike Price - 03/19/2018.

Young eagle at Money Hill, La. learning how to fly and is getting good at it.

Attached Images

               

[mikepl]

Those are beautiful shots!

However, aren't they a bit backfocussed? Have you calibrated AF microadjustment for the lens?

[joeji]

And another young eagle excelling in his photographic endeavors!

[mhsp1948]

mikepl, Back focused? help me out here, I don't know what you are talking about, I thought they turned out great.

[jpzk]

I think he meant for the first two shots with the eagle in the tree ... otherwise, the other in-flight shots seem quite good , perhaps a little bit "blurry" (shutter speed too slow ...?).
The last three shots are bang on.
Back focused: the focus "target" is a bit behind the intended target.
I.E.: the perfect focus is just behind the bird, as you can see with the twigs being very sharp vs. the bird itself.

---------- Post added 03-20-18 at 03:36 PM ----------

I think he meant for the first two shots with the eagle in the tree ... otherwise, the other in-flight shots seem quite good , perhaps a little bit "blurry" (shutter speed too slow ...?).
The last three shots are bang on.
Back focused: the focus "target" is a bit behind the intended target.
I.E.: the perfect focus is just behind the bird, as you can see with the twigs being very sharp vs. the bird itself.

You may want to take a look at this: Fixing Front and Back Focus - The Remedy - In-Depth Articles
That could be what is showing in the said "back focused" shots.
On the other hand, as mentioned, the other shots are fine so I doubt this is what happened with the first two shots .. maybe you aimed slightly behind the bird.

[aslyfox]

mikepl, Back focused? help me out here, I don't know what you are talking about, I thought they turned out great.

I'm a newbie

I would be proud to claim them as my own

back focus ???

perhaps but IMHO, I wouldn't change a thing


YMMV

[mikepl]

I believe jpzk managed to explain it better than I did. The last three seem preciesly focussed to me. The in-flight ones seem to have a tiny little bit blur to them, probably a bit slow shutter speed? In the first two it seems to me you focussed just behind the eagle, which could be either that the lens is backfocussing and would need microadjustment, or you by mistake focussed on the cones behind the eagle or something.

The shots are great anyway, no doubt about that!

[aslyfox]

I believe jpzk managed to explain it better than I did. The last three seem preciesly focussed to me. The in-flight ones seem to have a tiny little bit blur to them, probably a bit slow shutter speed? In the first two it seems to me you focussed just behind the eagle, which could be either that the lens is backfocussing and would need microadjustment, or you by mistake focussed on the cones behind the eagle or something.

The shots are great anyway, no doubt about that!

ok, teaching time folks, if you don't mind

the K 3 II and K 3 have different focusing modes correct ?

The K-3 does introduce some some new AF area modes, however:
Spot: focuses using the central AF point only
Auto-9: uses the central AF point as well as the 9 points surrounding it
Auto-27: uses all AF points based and automatically tries to identify your subject
SEL-1: lets you specify a single AF point to use
SEL-2/SEL-S: you specify a single starting AF point, but the AF system can utilize any of the Auto-9 AF points if your subject moves. The expanded area shift if you select a focus point close to any edge of the matrix.
SEL-3/SEL-M: you specify a single starting AF point, but the AF system can utilize any of the 25 cross-type points if your subject moves
SEL-4/SEL-L: you specify a single starting AF point, but the AF system can utilize any other AF point if your subject moves (all 27 points are in use)


Read more at: Pentax K-3 Review - Autofocus | PentaxForums.com Reviews

if you use any other mode other than spot focus, how does the camera lock on your target as oppose to the branch in front of the eagle or the pine cone or pine needle

can you folks help me out??

and how is that different from front/back focus problems

[clickclick]

if you use any other mode other than spot focus, how does the camera lock on your target as oppose to the branch in front of the eagle or the pine cone or pine needle can you folks help me out?? and how is that different from front/back focus problems

When you use a multi-point focus mode, the camera will lock onto one or more points it can grab, and "light" those points up in your viewfinder to indicate what it locked onto. You are effectively giving up some control with this, e.g. if you want to focus on an eye and use multi-point modes, you might get something other than the eye that the camera grabs instead. So, if you want total control on the exact focus point, use single point focus.

Front/back focus refers to an optical variation between the exact "in focus" point of rays of light coming through the lens versus where you sensor lies in relation to that point where all the light rays are "in focus". This doesn't mean there's anything wrong with the lens, and in fact, just about every lens I own including DA* lenses have needed a little calibration. This is because there are tolerances in the manufacturing process, so one of the first things I do when I get a new lens is dial in the front/back focus.

Hope this helps.

[aslyfox]

When you use a multi-point focus mode, the camera will lock onto one or more points it can grab, and "light" those points up in your viewfinder to indicate what it locked onto. You are effectively giving up some control with this, e.g. if you want to focus on an eye and use multi-point modes, you might get something other than the eye that the camera grabs instead. So, if you want total control on the exact focus point, use single point focus.

Front/back focus refers to an optical variation between the exact "in focus" point of rays of light coming through the lens versus where you sensor lies in relation to that point where all the light rays are "in focus". This doesn't mean there's anything wrong with the lens, and in fact, just about every lens I own including DA* lenses have needed a little calibration. This is because there are tolerances in the manufacturing process, so one of the first things I do when I get a new lens is dial in the front/back focus.

Hope this helps.

thanks

yes it does

nothing wrong with the instructor

the pupil

well that is a different story

[mikepl]

I will just add that knowing the real size of the af points helps A LOT. It is not just the red square that appears in the viewfinder, the actual size of the af point is much bigger. The focus can catch literally anything within its size so it is important to know. If you have not found it out yet, just make a simple test - draw a black dot onto a white paper, switch the camera to AF-C, SEL-1 mode, half pres shutter and slowly move towards the dot. Once the camera manages to focus onto the dot, you have found the edge of the af point. Then try it from many directions and with different af points and that´s it. Once I found out the real size, my keeper rate went instantly up.

[Larrymc]

ok, teaching time folks, if you don't mind

the K 3 II and K 3 have different focusing modes correct ?

The K-3 does introduce some some new AF area modes, however:
Spot: focuses using the central AF point only
Auto-9: uses the central AF point as well as the 9 points surrounding it
Auto-27: uses all AF points based and automatically tries to identify your subject
SEL-1: lets you specify a single AF point to use
SEL-2/SEL-S: you specify a single starting AF point, but the AF system can utilize any of the Auto-9 AF points if your subject moves. The expanded area shift if you select a focus point close to any edge of the matrix.
SEL-3/SEL-M: you specify a single starting AF point, but the AF system can utilize any of the 25 cross-type points if your subject moves
SEL-4/SEL-L: you specify a single starting AF point, but the AF system can utilize any other AF point if your subject moves (all 27 points are in use)


Read more at: Pentax K-3 Review - Autofocus | PentaxForums.com Reviews

if you use any other mode other than spot focus, how does the camera lock on your target as oppose to the branch in front of the eagle or the pine cone or pine needle

can you folks help me out??

and how is that different from front/back focus problems

Front or back focus is independent of what ever focusing mode the camera is in the only exception is live view which should render almost perfect focus every time with a few exceptions.
The camera sensor and the camera A/F module and lens have to be in sync. meaning that the camera can indicate that it is correctly focused and and still not take an in focus shot because of the alignment of the focusing module which is usually located at the bottom of the camera body beneath the mirror. The camera as shipped has the AF Fine adjustment set to +/-0 which may or may not render a perfectly in focus shot. When taking a photo there are three outcomes perfect focus, back focus, front focus. This is because the lens is usually manufactured at a different company or location than the camera and the first time each work together is when they are mated together by a photographer so they need to be calibrated. Modern manufacturing precision tolerances being what they are there is rarely a perfect match of lens and camera unless they are calibrated as a unit.

There are many and varied methods to fine tune the autofocus. Google autofocus fine tune for an education on this subject.

Larry

[clickclick]

the pupil well that is a different story

For that, there are people who charge an hourly rate....

[Larrymc]

I will just add that knowing the real size of the af points helps A LOT. It is not just the red square that appears in the viewfinder, the actual size of the af point is much bigger. The focus can catch literally anything within its size so it is important to know. If you have not found it out yet, just make a simple test - draw a black dot onto a white paper, switch the camera to AF-C, SEL-1 mode, half pres shutter and slowly move towards the dot. Once the camera manages to focus onto the dot, you have found the edge of the af point. Then try it from many directions and with different af points and that´s it. Once I found out the real size, my keeper rate went instantly up.

Good idea! Sounds a bit like an electronic stud finder used to find studs behind drywall.

Larry

[mhsp1948]

I think he meant for the first two shots with the eagle in the tree ... otherwise, the other in-flight shots seem quite good , perhaps a little bit "blurry" (shutter speed too slow ...?).
The last three shots are bang on.
Back focused: the focus "target" is a bit behind the intended target.
I.E.: the perfect focus is just behind the bird, as you can see with the twigs being very sharp vs. the bird itself.

---------- Post added 03-20-18 at 03:36 PM ----------


You may want to take a look at this: Fixing Front and Back Focus - The Remedy - In-Depth Articles
That could be what is showing in the said "back focused" shots.
On the other hand, as mentioned, the other shots are fine so I doubt this is what happened with the first two shots .. maybe you aimed slightly behind the bird.

Thank you for explaining.

---------- Post added 03-20-18 at 06:36 PM ----------

Thanks for the info you all discussed it does help out.