Group mode focus and focus point used

I don't see this question, so...

Nikon D500, Sigma 150-600C.

I shot a bunch of images in Kearney or the Sandhill Cranes earlier this year. And the VAST majority are not sharp. In some cases, the light was garbage and I was shooting between 1/100 and 1/200 at f6.3 and ISO 1600 (as I said, garbage)... BUT, not ALL.

So, I downloaded the ShowFocusPoints Add-on for Lightroom and after rejecting over 600 of 900 images on the initial culling pass, I started looking at some.

My question is in how the Show Focus Points works (or focus points in general...

Here's the exif data with one of the images:

Camera: Nikon D500
Lens: 150-600
Focal Length: 600mm
Exposure: 1/800, f/8.0, ISO 800

Focus mode: AF-C
AF area mode: Group Area
Contrast Detect AF: Off
Phase Detect AF: On (153 point)
Auto Focus: on
AF aperture: 6.3

Focus Distance 74.99M
Depth of field 4.97m
Number of AF points selected before taking picture: 1
Number of AF points where focus was achieved: 1

Pretty much EVERYTHING I shot of the birds was EITHER 74.99m or 125.89m, which says to me that the distance may not be real accurate.

Here's one of the images with the focus point shown. The show focus says: Red+black: locked AF point (Focus achieved), also primary AF point













This particular image was at 125.89 m, and you can see the focus point in the first image. The second image is the actual subject, which is BADLY out of focus.

I'm using GROUP auto-focus, which as far as I know is using 9 focus points around the "center" point. I believe my "center" point for the group focus is the center point of the viewfinder. But, it doesn't show whole set, so is the software displaying the point of the group that actually got used?

In which case, since I have a reasonable number of images where the point used for focusing IS on the subject, I"m trying to figure out if I have a camera problem, a lens problem, a technique problem (always the most likely) or some combination...

I get good, sharp results when I'm reasonably close but a huge percentage of these distant shots (somewhere I presume between 75 and 125 meters) are garbage, even when the exif data says the focus locked on the subject. I can see camera movement on SOME, but the vast majority were shot using a beanbag on the window of a truck, with the engine off. Pretty much everything was shot as a series at 10 fps, and in general, ALL of the images in a series are garbage.

SO, should I be using something other than group AF, like single point, or 3D and let it track the subject, or something else? OR, do I have a lens that somehow needs to be calibrated at long distances because it's not focusing correctly once the subject gets further from the camera?

I'll do some testing when I get home Monday, but a lot of these images don't look like ANYTHING in the image is anywhere near being sharp.

Thoughts?

dperez said:

I don't see this question, so...

Nikon D500, Sigma 150-600C.

I shot a bunch of images in Kearney or the Sandhill Cranes earlier this year. And the VAST majority are not sharp. In some cases, the light was garbage and I was shooting between 1/100 and 1/200 at f6.3 and ISO 1600 (as I said, garbage)... BUT, not ALL.

So, I downloaded the ShowFocusPoints Add-on for Lightroom and after rejecting over 600 of 900 images on the initial culling pass, I started looking at some.

My question is in how the Show Focus Points works (or focus points in general...

Here's the exif data with one of the images:

Camera: Nikon D500
Lens: 150-600
Focal Length: 600mm
Exposure: 1/800, f/8.0, ISO 800

Focus mode: AF-C
AF area mode: Group Area
Contrast Detect AF: Off
Phase Detect AF: On (153 point)
Auto Focus: on
AF aperture: 6.3

Focus Distance 74.99M
Depth of field 4.97m
Number of AF points selected before taking picture: 1
Number of AF points where focus was achieved: 1

Pretty much EVERYTHING I shot of the birds was EITHER 74.99m or 125.89m, which says to me that the distance may not be real accurate.

Here's one of the images with the focus point shown. The show focus says: Red+black: locked AF point (Focus achieved), also primary AF point





This particular image was at 125.89 m, and you can see the focus point in the first image. The second image is the actual subject, which is BADLY out of focus.

I'm using GROUP auto-focus, which as far as I know is using 9 focus points around the "center" point. I believe my "center" point for the group focus is the center point of the viewfinder. But, it doesn't show whole set, so is the software displaying the point of the group that actually got used?

In which case, since I have a reasonable number of images where the point used for focusing IS on the subject, I"m trying to figure out if I have a camera problem, a lens problem, a technique problem (always the most likely) or some combination...

I get good, sharp results when I'm reasonably close but a huge percentage of these distant shots (somewhere I presume between 75 and 125 meters) are garbage, even when the exif data says the focus locked on the subject. I can see camera movement on SOME, but the vast majority were shot using a beanbag on the window of a truck, with the engine off. Pretty much everything was shot as a series at 10 fps, and in general, ALL of the images in a series are garbage.

SO, should I be using something other than group AF, like single point, or 3D and let it track the subject, or something else? OR, do I have a lens that somehow needs to be calibrated at long distances because it's not focusing correctly once the subject gets further from the camera?

I'll do some testing when I get home Monday, but a lot of these images don't look like ANYTHING in the image is anywhere near being sharp.

Thoughts?

Click to expand...

Have you done an AF fine tune at 600mm or used to Sigma Dock to fine tune?

Morris

Morris0 said:

dperez said:

I don't see this question, so...

Nikon D500, Sigma 150-600C.

I shot a bunch of images in Kearney or the Sandhill Cranes earlier this year. And the VAST majority are not sharp. In some cases, the light was garbage and I was shooting between 1/100 and 1/200 at f6.3 and ISO 1600 (as I said, garbage)... BUT, not ALL.

So, I downloaded the ShowFocusPoints Add-on for Lightroom and after rejecting over 600 of 900 images on the initial culling pass, I started looking at some.

My question is in how the Show Focus Points works (or focus points in general...

Here's the exif data with one of the images:

Camera: Nikon D500
Lens: 150-600
Focal Length: 600mm
Exposure: 1/800, f/8.0, ISO 800

Focus mode: AF-C
AF area mode: Group Area
Contrast Detect AF: Off
Phase Detect AF: On (153 point)
Auto Focus: on
AF aperture: 6.3

Focus Distance 74.99M
Depth of field 4.97m
Number of AF points selected before taking picture: 1
Number of AF points where focus was achieved: 1

Pretty much EVERYTHING I shot of the birds was EITHER 74.99m or 125.89m, which says to me that the distance may not be real accurate.

Here's one of the images with the focus point shown. The show focus says: Red+black: locked AF point (Focus achieved), also primary AF point





This particular image was at 125.89 m, and you can see the focus point in the first image. The second image is the actual subject, which is BADLY out of focus.

I'm using GROUP auto-focus, which as far as I know is using 9 focus points around the "center" point. I believe my "center" point for the group focus is the center point of the viewfinder. But, it doesn't show whole set, so is the software displaying the point of the group that actually got used?

In which case, since I have a reasonable number of images where the point used for focusing IS on the subject, I"m trying to figure out if I have a camera problem, a lens problem, a technique problem (always the most likely) or some combination...

I get good, sharp results when I'm reasonably close but a huge percentage of these distant shots (somewhere I presume between 75 and 125 meters) are garbage, even when the exif data says the focus locked on the subject. I can see camera movement on SOME, but the vast majority were shot using a beanbag on the window of a truck, with the engine off. Pretty much everything was shot as a series at 10 fps, and in general, ALL of the images in a series are garbage.

SO, should I be using something other than group AF, like single point, or 3D and let it track the subject, or something else? OR, do I have a lens that somehow needs to be calibrated at long distances because it's not focusing correctly once the subject gets further from the camera?

I'll do some testing when I get home Monday, but a lot of these images don't look like ANYTHING in the image is anywhere near being sharp.

Thoughts?

Click to expand...

Have you done an AF fine tune at 600mm or used to Sigma Dock to fine tune?

Morris

Click to expand...

In addition to the point made by Morris, I'd choose a shutter speed higher than 800 for birds in flight. Typically on a D500 paired with a 200-500 I'd start at 1000 or 1250 and after a few early shots, if the light is bad, adjust for exposure to reduce noise. With a 150-600 I'd probably start at 1250.

I can’t find the source for this right now but I’m pretty sure it was either Thom Hogan’s book or one of his blog posts. However, my understanding is that in Group mode the camera does not record the actual focus point used, just the central point of the group set. The photo you put up clearly indicates the central point. Check all your other photos, if it is always showing the same point, that would verify that statement. If it moves about within the group, it will disprove it.

Was OS on or off?

I used the Sigma C for over a year and noticed that its OS could shift the focus point slightly.

Even when shooting perched birds I used to fire off a few "insurance" shots while refocusing in between them.

It still was not the most consistent lens re focus accuracy.

Thanks for the replies...

"Have you done an AF fine tune at 600mm or used to Sigma Dock to fine tune?"

I've done a couple things in the dock: I set the OS to the most aggressive setting so it actually stabilizes (on the mild setting there's virtually no stabilization as near as I can tell). And, I've set the autofocus to the fastest and most aggressive because the "slower but more precise is REALLY slow - and not much more precise because the subject is gone by the time the focus gets it's act together.

I also tried using the camera's AF fine tuning using the Dot-tune method and made such a total mess out of it that I finally zeroed everything and left it alone... I was putting in movements and getting the dot-tune to align, but the images weren't any better, so I decided I was doing it wrong and zeroed it 'cause up CLOSE or reasonably close the focusing seems reasonably good.

I tried using the dock to tune the lens instead of the camera but that was SO haphazard and inconsistent I quit. If somebody can provide a method that will enable me to methodically and verifiably adjust the focus using the dock, I'd be glad to try it.

When I get home (presuming the umpteen-day-long monsoon ends) I can put the camera on the very sturdy tripod, set up a page-sized chart at an angle, with a scale to see focus point at 25 yards or so and see how the focus looks. I can compare it with the Sigma 50-500 I have and the Nikon 500 f/4, and see how they all look. Maybe THIS time I'll get some useful information on the 150-600 front or back focusing 'cause as I said, last time I made some kind of total mess of things... So, again, anyone have a step-by-step method for using the dock and HOW MUCH distance the changes mean (if I'm front focusing 2 inches HOW MUCH do I change the number in the dock?) I'd be happy to play.

"In addition to the point made by Morris, I'd choose a shutter speed higher than 800 for birds in flight. Typically on a D500 paired with a 200-500 I'd start at 1000 or 1250 and after a few early shots, if the light is bad, adjust for exposure to reduce noise. With a 150-600 I'd probably start at 1250."

So would I, but as I said in the original post, the light was sh*t. I have images shot at 1/100, f/6.3, ISO 1600 it was so bad.

Unfortunately, once the sun came out and I went to 1/2500, f/10, ISO 400 things did NOT improve... Still appallingly poor images. I haven't gotten to those yet with the show focus, but I threw out at least 90% of those too because of the lousy focus. Some, I'm sure will be missed focus but not this many.

"my understanding is that in Group mode the camera does not record the actual focus point used, just the central point of the group set. The photo you put up clearly indicates the central point. Check all your other photos, if it is always showing the same point, that would verify that statement. If it moves about within the group, it will disprove it."

Here are 2 images in sequence, so they should be around 1/10 second apart. The focus point has changed, so I THINK it's showing which point in the group actually focused... And it SAYS (red with black square) that that point "ACHIEVED" focus, which I presume means the camera was PAST the refocus delay and was actually FOCUSED. And NEITHER one is in focus where the focus point says it's successfully focused...





Which makes me question my delay settings on the camera... There's the "delay before refocusing" setting and the "erratic vs smooth movement" setting... I have the delay before refocusing set to short but not immediate and the erratic vs smooth set to average... These birds aren't erratic - they're big, slow birds, coming in slowly and smoothly at a distance of 74.99 meters (is it reasonable for 900 shots to ALL be at either 74,99 or 125.89 meters?) according to the exif data... Should I be changing THOSE settings to something else?

"Was OS on or off?

"I used the Sigma C for over a year and noticed that its OS could shift the focus point slightly. Even when shooting perched birds I used to fire off a few "insurance" shots while refocusing in between them. It still was not the most consistent lens re focus accuracy."

The OS was on, and I was shooting bursts exactly BECAUSE when shooting subjects like this I know my focus may vary. I'm expecting a significant number of failures, but this many throwaways because of focus seems excessive...

It sounds to me like time to TRY to get some empirical data with the camera and a couple long lenses, and see if I get the same problem at home... I can put the target out further, but I"m not sure what to use as a target for focusing at 50 (or so) yards that I'll be able to SEE where the focus is... So, testing method and target ideas?

..Wow, where to begin..

..just to let you know, both the D500 camera and the Sigma 150-600mm Contemporary lens are in my collection too..

..first, it's good of you for posting the pictures so we can see them..

..recommend.. before getting to the 'harder' stuff.. better to start with the basics first..

..recommend doing focus accuracy test(s), such as the example below..


..example of my focus accuracy test..

..next, you mentioned that your lens has been adjusted.. but I will mention just to confirm.. see below..

1. set the lens 'os setting' to 'dynamic view mode'..


..dynamic view mode..

2. set the 'af speed setting' to 'motor's drive speed-priority'..


..motor's drive speed-priority..

***********

..the Sigma 150-600mm Contemporary lenses 'sweet spot' is f/8..

..you can shoot it at f/6.3, but don't be surprised if the image(s) are 'soft'..

..if need to, I would shoot it at f/7.1..

***********

..the D500 camera, when used with the Sigma 150-600mm C lens..

..for birds & wildlife, works best at 1/1250, 1/1600, 1/2000 speeds..

..of course can go higher shutter speeds if needed..

***********

..for my D500 camera, usually have set to max iso3200..

..and if need to, can go max iso6400..

***********

..for my D500, I mostly either use 'group focus' or 'single focus' point(s)..

..using AF-C works well..

..and be sure to turn 'on' the 'face-detection'..

***********

..some other details..

..often times prefer 'center-weighed' metering, otherwise 'matrix'..

..noise reduction 'normal..

..active-d lighting 'auto'..

..within 'picture control', sharpening set to (a)uto, contrast set to (a)uto, clarity set to '0' (default is +1)..

..if need to, use +0.33ev or +0.66ev..

..best to fill the 'frame' with the 'subject', and not to rely on 'cropping' as much..

***********

..try, experiment, and have fun..

..Cheers..

--
Regards, John..
..down with naysayers!
[YI M1 camera, Olympus 17mm f/1.8 lens, firmware 3.0]

We do not know what focal length you used but without IS the starting point for some shots sharp on DX with a 600mm focal length works out at 900mm plus a bit for a moving subject - say 1/2000 for most shots sharp.

IS might gain you 2-3 stops but ideally you still need at least 1/500 to allow for camera shake. IS does not help with subject movement.

Part of the problem seems you needed faster shutter speeds.

Another potential issue is 9 point group AF only works well if the subject temporarily moves away from the central AF point.

To help keep the intended subject under the central AF point many use a Gimbal type tripod head on a good tripod.

--
Leonard Shepherd
In lots of ways good photography is much more about how equipment is used rather than the equipment being used.

jshen808 said:

..Wow, where to begin..

..just to let you know, both the D500 camera and the Sigma 150-600mm Contemporary lens are in my collection too..

..first, it's good of you for posting the pictures so we can see them..

..recommend.. before getting to the 'harder' stuff.. better to start with the basics first..

..recommend doing focus accuracy test(s), such as the example below..


..example of my focus accuracy test..

..next, you mentioned that your lens has been adjusted.. but I will mention just to confirm.. see below..

1. set the lens 'os setting' to 'dynamic view mode'..


..dynamic view mode..

2. set the 'af speed setting' to 'motor's drive speed-priority'..


..motor's drive speed-priority..

***********

..the Sigma 150-600mm Contemporary lenses 'sweet spot' is f/8..

..you can shoot it at f/6.3, but don't be surprised if the image(s) are 'soft'..

..if need to, I would shoot it at f/7.1..

***********

..the D500 camera, when used with the Sigma 150-600mm C lens..

..for birds & wildlife, works best at 1/1250, 1/1600, 1/2000 speeds..

..of course can go higher shutter speeds if needed..

***********

..for my D500 camera, usually have set to max iso3200..

..and if need to, can go max iso6400..

***********

..for my D500, I mostly either use 'group focus' or 'single focus' point(s)..

..using AF-C works well..

..and be sure to turn 'on' the 'face-detection'..

***********

..some other details..

..often times prefer 'center-weighed' metering, otherwise 'matrix'..

..noise reduction 'normal..

..active-d lighting 'auto'..

..within 'picture control', sharpening set to (a)uto, contrast set to (a)uto, clarity set to '0' (default is +1)..

..if need to, use +0.33ev or +0.66ev..

..best to fill the 'frame' with the 'subject', and not to rely on 'cropping' as much..

***********

..try, experiment, and have fun..

..Cheers..

--
Regards, John..
..down with naysayers!
[YI M1 camera, Olympus 17mm f/1.8 lens, firmware 3.0]

Click to expand...

I have the same setup and was hoping you had a Flickr to look at your results. Thanks!

Hi dperez,

One of your issues may be caused by using Group autofocus. Exactly how the D500 picks a focus point in Group mode is not clear; most of the time it seems to be the closest subject, so you may not be getting focus where you want it.

In his D500 Guide Thom Hogan says:

“Grp or Group autofocus—the camera always determines focus by itself from one of thirteen autofocus sensors (the four that are highlighted in the viewfinder and the implied ones that connect and are within those four). You can move the “group” around via the Direction pad, but you can’t select which of the thirteen focus sensors are actually used for focusing…. the “dynamic” modes always try to focus on your selected focus sensor and only move if they can’t reliably determine focus at that position or the subject moves. The Group setting always picks the focus point on its own, with some voodoo magic that Nikon hasn’t really described. That voodoo magic is mostly this: closest focus priority….”

Shooting birds I almost always use 72-point Dynamic area autofocus.

I also shot the Sandhill Cranes in Nebraska this year with the D500 and 200-500 mm. Here’s a couple, the first at 500 mm and the second at 480 mm; handheld.

Leonard Shepherd said:

We do not know what focal length you used but without IS the starting point for some shots sharp on DX with a 600mm focal length works out at 900mm plus a bit for a moving subject - say 1/2000 for most shots sharp.

IS might gain you 2-3 stops but ideally you still need at least 1/500 to allow for camera shake. IS does not help with subject movement.

Part of the problem seems you needed faster shutter speeds.

Another potential issue is 9 point group AF only works well if the subject temporarily moves away from the central AF point.

Click to expand...

Group AF mode doesn’t actually give priority/bias to the central focus point. The algorithm can choose its own focus sensor and, though Nikon aren’t really clear on this, it seems to favour the closest object within the diamond group of 13 sensors. It is the Dynamic AF modes that definitely favour the group’s central sensor.

Leonard Shepherd said:

To help keep the intended subject under the central AF point many use a Gimbal type tripod head on a good tripod.

--
Leonard Shepherd
In lots of ways good photography is much more about how equipment is used rather than the equipment being used.

Click to expand...

Intercooler2 said:

I have the same setup and was hoping you had a Flickr to look at your results. Thanks!

Click to expand...

..taking bif pictures is interesting to me, but it's not my passion..

..probably the most controversial part of my posting..

..is the use of 'group focus', I recommend it because I use it, and works well for me..

..others may find using the various-points 'dynamic areas' autofocus to be more useful, and that's fine..

..best to use what 'works' for an individual..

..but I highly recommend turning 'on' the 'facial detection', and give it a try..

************

..these days, I prefer to use my P900 (or P610) camera(s) to take wildlife pictures, because I need the 1200mm+ efov zoom..


..P900 camera, full sized sooc jpeg image, no post processings, 2000mm efov..

..and use my D500 camera, with group focus, facial detection 'on', and high burst capture.. to take events pictures, with a blink of an eye, no longer than a few seconds of time to take a burst of pictures of these lovely ladies, then I'm off to the next..


..D500 camera, using group focus, facial detection 'on', and high burst capture.. full sized sooc jpeg image, no post processings..

***********

..you had mentioned that you use the same or similar settings as I do..

..and how has it been working for you(?)..

***********

..try, experiment, and have fun..

..Cheers..

--
Regards, John..
..down with naysayers!
[YI M1 camera, Olympus 17mm f/1.8 lens, firmware 3.0]

jshen808 said:

..example of my focus accuracy test..

Click to expand...

..had forgotten to mention..

..for the above focus accuracy testings..

..best to use AF-S, and Single-focus point..

***********

..try, experiment, and have fun..

..Cheers..

--
Regards, John..
..down with naysayers!
[YI M1 camera, Olympus 17mm f/1.8 lens, firmware 3.0]

Thanks again for the replies everybody. Whether this turns out to be lousy conditions or something else, getting feedback on what people are doing, even when I'm doing those things, is very helpful. Sometimes it useful to know what you're doing right so you can narrow down the "what I'm doing wrong" options… I went back as far as spring of 2017 to look at other occasions when I was chasing birds in flight (several thousand ended up in teh LR catalog). Success varies, but I'm USUALLY had pretty decent luck. Which is making me suspect something OTHER than equipment (like my technique). Yes, the lighting was abysmal, but I was shooting with the camera on a beanbag, so even 1/200 SHOULD have been reasonably sharp - not every shot, but SOME. And a lot of these aren't SLIGHTLY out of focus, they're WAY WAY out of focus!

Mark_dpr said:

Jshen808 "..recommend doing focus accuracy test(s), such as the example below.."

Click to expand...

I got outside yesterday evening with the D500, Sigma 150-600 and Sigma 50-500. On a sturdy tripod, using AF-C (I've never used this lens in AF-S, in fact, it's locked out of that mode), mirror-up mode, remote release, matrix metering and group focus mode, which is what I almost always use for bif (I spent a good bit of time playing with Dynamic AF, but that's another topic). With the 150-600 I shot a focus target at 600mm and f/6.3 from 8 meters, 17 meters and 42 meters. When POSSIBLE, I always shoot at f/8 or f/11 with this lens, but I kept it wide open for testing. All shots looked good, with the text appearing sharp and clear even from 40 meters. No obvious focus problems.
I also shot subjects WAY further away than 125 meters and I suspect now that the 75 meter and 125 meter numbers in subject distance have no meaning (infinity perhaps?)... From a couple hundred yards I shot a block wall and it's sharp and detailed. From about 1/4 mile I shot a hotel sign and it's also sharp. The group focus point that got used WASN'T the center one, and it wasn't on the sign, but it was on the wall behind so it's all sharp. I shot a church steeple well over a quarter mile away and it's good. I did similar things with the 50-500 and got similar results... The steeple MAY not be quite as sharp as what I'd get from the Nikon 500, f/4, but I'm not sure it's fair to compare a fixed focal length lens that's 8 times more expensive to either of the Sigmas. None of these was moving. I wasn't panning, the light wasn't great - someday we'll have sunshine here in Minnesota, but not for the last 5 days.

Mark_dpr said:

"..next, you mentioned that your lens has been adjusted.. but I will mention just to confirm.." 1. set the lens 'os setting' to 'dynamic view mode'.. 2. set the 'af speed setting' to 'motor's drive speed-priority'..

Click to expand...

Those are what I have in custom C1 - Dynamic view mode for maximum stabilization and Fast AF Priority, which I suspect is the same as your AF speed setting

Mark_dpr said:

***

..the Sigma 150-600mm Contemporary lenses 'sweet spot' is f/8.. you can shoot it at f/6.3, but don't be surprised if the image(s) are 'soft'.. if need to, I would shoot it at f/7.1..

Click to expand...

In any kind of "normal" conditions I'd NEVER shoot below f/8, use ISO 1600 OR shoot at 1/100… This was MIDDAY and it was like after dusk for TWO STINKING DAYS! I should'a stood in bed!

Mark_dpr said:

*** ..for my D500, I mostly either use 'group focus' or 'single focus' point(s).. ..using AF-C works well.. ..and be sure to turn 'on' the 'face-detection'..

Click to expand...

I typically use either single focus point or group. On this occasion, group. What does turning on the 'face detection" do for shooting wildlife or things without faces?

Mark_dpr said:

**** ..often times prefer 'center-weighed' metering, otherwise 'matrix'.. ..noise reduction 'normal.. ..active-d lighting 'auto'..

Click to expand...

I typically use Matrix, and noise reduction normal. Lightroom doesn't use the information from active d-lighting (I checked), so I leave it off.

Mark_dpr said:

..within 'picture control', sharpening set to (a)uto, contrast set to (a)uto, clarity set to '0' (default is +1).. ..if need to, use +0.33ev or +0.66ev.. ..best to fill the 'frame' with the 'subject', and not to rely on 'cropping' as much..

Click to expand...

I'm using Neutral so I have +2 sharpening and 0 for everything else. I absolutely agree about filling the frame when possible. In this case, these were the CLOSEST birds!

Mark_dpr said:

Leonard Shepherd We do not know what focal length you used but without IS the starting point for some shots sharp on DX with a 600mm focal length works out at 900mm plus a bit for a moving subject - say 1/2000 for most shots sharp. IS might gain you 2-3 stops but ideally you still need at least 1/500 to allow for camera shake. IS does not help with subject movement. Part of the problem seems you needed faster shutter speeds.

Click to expand...

Yes, the shutter speeds are too low, the aperture is too wide and the ISO is too high… It was midday and that's ALL the light there was. I used a beanbag on the window for the majority of the shots, and expected quite a few failures… Just not 100%.

Mark_dpr said:

Another potential issue is 9 point group AF only works well if the subject temporarily moves away from the central AF point.

Click to expand...

I believe this MAY be incorrect. My understanding is that Dynamic AF does that, and from my testing it did - move the center point of the dynamic area off the subject and after the delay it focuses on whatever the center point is now on. My understanding is this was changed from how it worked previously and the D5, D500 and D850 (my other regular body) all do this. There's a HUGE discussion elsewhere that went on for months and 30 pages about exactly how Dynamic AF works, how it should work, why it DOESN'T work, and whether it's a Nikon plot, accident, or the coming apocalypse! As far as I know, and again from my testing last evening, in Group AF, I can move the center point off the subject and it'll keep that subject in focus unless something shows up that's closer than the subject… When I was shooting a sign a couple blocks away it stayed on the sign even though the center point was over a building way behind the sign, til a car went by, between me and the sign, at which point after the delay (set at 2, so it's short), the camera focused on the car.

Mark_dpr said:

To help keep the intended subject under the central AF point many use a Gimbal type tripod head on a good tripod.

Click to expand...

Have both the sturdy tripod AND the Gimbal head, and use them when I'm shooting the Nikon 500, f/4, especially when the 1.4X is on it. It's not usable in the situation I was in 'cause the birds immediately scattered if a human got out of their car. Instead I used a beanbag on the window (and the truck off of course) as a substitute.

Mark_dpr said:

Mark_dpr

Click to expand...

As you may have noticed (and cringed at) your images of the cranes are LIGHT-YEARS better than anything I got this year!

Mark_dpr said:

One of your issues may be caused by using Group autofocus. Exactly how the D500 picks a focus point in Group mode is not clear; most of the time it seems to be the closest subject, so you may not be getting focus where you want it.

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Mark, I haven't read Thom Hogan's D500 Guide, though I've heard it's excellent. The information I found at Photographylife for Group AF says: Within the viewfinder you see four focus points, with the fifth one in the middle hidden. All five focus points are activate for the initial focus acquisition, with priority given to the closest subject without giving preference to any of the 5 focus points. As long as one of the 5 focus points is near the (closest) subject, the camera will stay focused on the subject. Group-area AF will also track the subject, if one of the 5 focus points is near the subject. What I don't understand is the "near"… Nikon shows Dynamic AF with all the intermediate focus points between the visible ones. I haven't found any pictures of Group AF that shows ANY points other than the 4 that are visible and the 5th one in the center. I don't know if it actually uses the intermediate (implied?) focus points between the visible ones or not. So, what does it mean when they say "near" instead of "on the subject"? In any case, I've usually used Group AF for chasing things that are flying 'cause their the closest thing and hopefully the background is far enough away that nothing gets confused. BUT, after this experience, and some of the feedback I've gotten, I'll definitely try D25 or D72 next time I'm in a situation where I have lots of birds…

dperez said:

*** ..for my D500, I mostly either use 'group focus' or 'single focus' point(s).. ..using AF-C works well.. ..and be sure to turn 'on' the 'face-detection'..

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I typically use either single focus point or group. On this occasion, group. What does turning on the 'face detection" do for shooting wildlife or things without faces? [end quote]

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..Wow, from your write-up, you've taken this and done wonderful experiments!

..it is wonderful everyone chimed in this discussion, and have good feedbacks and suggestions.. this is how we learn from each other.. :-D

..now to your question about facial detection on wildlifes..

..from my experiences using group focus & facial detection 'on', both humans & wildlifes are recognized.. ;-)

..see the below examples..


..D500 camera, group focus, facial detection 'on'.. the center of the group focus is on the lovely lady of the middle bottom row.. only had a second to take this picture, then all is over..


..D500 camera, group focus, facial detection 'on'..


..D500 camera, group focus, facial detection 'on'..

..try, experiment, and have fun..

..Cheers..

--
Regards, John..
..down with naysayers!
[YI M1 camera, Olympus 17mm f/1.8 lens, firmware 3.0]

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Neat cow! It made me chuckle! OK, I'll turn it on! I THINK it only works when the camera is in AF-S, but if it makes it easier to get better images I'll try it!

Thanks!

Tomorrow - IT'S SUPPOSED TO NOT BE DARK, DULL AND RAINING all day, so I'm HOPING to get outside and see if there's any benefit to calibrating the 400 and 600mm focal lengths at the ~45 foot and infinity settings... It should be interesting trying to read a calibration chart when it's far enough away to cause this lens to be at infinity!

dperez said:

Neat cow! It made me chuckle! OK, I'll turn it on! I THINK it only works when the camera is in AF-S, but if it makes it easier to get better images I'll try it!

Thanks!

Tomorrow - IT'S SUPPOSED TO NOT BE DARK, DULL AND RAINING all day, so I'm HOPING to get outside and see if there's any benefit to calibrating the 400 and 600mm focal lengths at the ~45 foot and infinity settings... It should be interesting trying to read a calibration chart when it's far enough away to cause this lens to be at infinity!

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..Lol's! :-D

..ohh, forgot to mention, that below is what I use..

..use AF-C, group focus, facial detection 'on'.. ;-)

..Good luck!

dperez said:

I don't see this question, so...

Nikon D500, Sigma 150-600C.

I shot a bunch of images in Kearney or the Sandhill Cranes earlier this year. And the VAST majority are not sharp. In some cases, the light was garbage and I was shooting between 1/100 and 1/200 at f6.3 and ISO 1600 (as I said, garbage)... BUT, not ALL.
[snip]
Here's one of the images with the focus point shown. The show focus says: Red+black: locked AF point (Focus achieved), also primary AF point

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At 600mm with a DX camera, I would resist the urge to press the shutter release unless the subject fills at least twice as much of the frame as in this image. The more your subject fills the frame, the better the overall image quality will be.

--
Bill Ferris Photography
Flagstaff, AZ

I didn't read all the replies so maybe this is double:

If you shoot from a car window on a sunny day the car or the tarmac may be hot causing turbulence just in front of your lens. In that case every image will be garbage, the longer the focal length the worse it gets.

If you shot a lot at 1/100 or 1/200 as your original post says I'm kinda not surprised with the results for birds in flight.