Trying to decide if my MFA is correct.

Shooting with a 5D4 and sigma 60-600. It was back focusing when I first starting making the adjustments. I have it at -6 now. I took several bird shots from a bird blind and felt like it was pretty good. I have a couple of owl pics here to post. Both of them look pretty good in the face but the feather detail in the chest looks soft. Both shots were handheld. Both shots were shot wide open. These are 100 percent crops. I am wondering if it is still back focusing just a bit.

This first pic was at 1/250 ISO 1000 233mm

https://www.the-outdoorsman.net/temp/s​ample1.jpg

The second pic was at 1/500 ISO 200 600mm

https://www.the-outdoorsman.net/temp/s​ample2.jpg

Are you aware of the SS<1/FL rule of thumb? In the first one you are flirting too close, 1/250 is marginally less than 1/233. I'd shoot at least 1/500 if not 1/1000.

The other photo flouts the rule of thumb 1/500>1/600.

This rule of thumb purports to prevent camera motion being registered in the shot.

I think your photos are correct. On the owl, the face feathers are, well, feathers. But on the body the feathers are more like fur. I think you got what would be expected. Here's a similar shot. BTW, I'm really looking forward to the Daytona 500! I love the NASCAR season.

With long focal lengths, you’re probably getting more shallow DoF. From what I can tell from the photos, you would get more in focus with stopped down aperture.

MakisM1 wrote in post #19005085
Are you aware of the SS<1/FL rule of thumb? In the first one you are flirting too close, 1/250 is marginally less than 1/233. I'd shoot at least 1/500 if not 1/1000.

The other photo flouts the rule of thumb 1/500>1/600.

This rule of thumb purports to prevent camera motion being registered in the shot.

Yes I am. I figured with the detail in the face being pretty good that the body should have been close to the same. That is why I started the thread. Judging from the other post stating the body feathers are more like fur then maybe it is just that.

LJ3Jim wrote in post #19005175
I think your photos are correct. On the owl, the face feathers are, well, feathers. But on the body the feathers are more like fur. I think you got what would be expected. Here's a similar shot. BTW, I'm really looking forward to the Daytona 500! I love the NASCAR season.

That must be it. The bird shots I took after I did my MFA looked good. I used a tripod on those shots. Daytona should be a good race.

MakisM1 wrote in post #19005085
Are you aware of the SS<1/FL rule of thumb? In the first one you are flirting too close, 1/250 is marginally less than 1/233. I'd shoot at least 1/500 if not 1/1000.

The other photo flouts the rule of thumb 1/500>1/600.

This rule of thumb purports to prevent camera motion being registered in the shot.

It's not a rule, it's a guideline and applicable to handheld shots without IS. IS changes things quite a bit. I would think that the formula needs to be update. Something like this.

(Shutter speed = 1/ Focal length) / (2 to the power of the IS capability of the lens).

As the 60-600 has a 4 stop IS, it should be SS = (1/600) / (2^4) or in camera terms, SS= 750 / 16 or roughly 1/60th as a minimum so 1/250 or 1/500 should be fine assuming that IS was on.

Nascar Nut wrote in post #19004990
Shooting with a 5D4 and sigma 60-600. It was back focusing when I first starting making the adjustments. I have it at -6 now. I took several bird shots from a bird blind and felt like it was pretty good. I have a couple of owl pics here to post. Both of them look pretty good in the face but the feather detail in the chest looks soft. Both shots were handheld. Both shots were shot wide open. These are 100 percent crops. I am wondering if it is still back focusing just a bit.

This first pic was at 1/250 ISO 1000 233mm

https://www.the-outdoorsman.net/temp/s​ample1.jpg

The second pic was at 1/500 ISO 200 600mm

https://www.the-outdoorsman.net/temp/s​ample2.jpg

Let's assume that the total depth of the owl, as it stand, is 1ft and you're about 100ft away. The online calculator shows that you got about 3ft of sharpness for 600mm; so likely you have focus issue. Try MFA to -16

It's a good photo, regardless.

BTW, for testing of MFA at 200mm+ go outside and shoot your roof shingles.

The OP's owls really are in focus. The texture of the feathers on the body is drastically different than the head, and that's why it looks like it's not. Here's a crop from the lower left of the OP's second image. The individual fibers that are isolated in front of the darker area are nice and sharp.

Trey T wrote in post #19005509
BTW, for testing of MFA at 200mm+ go outside and shoot your roof shingles.

That's a really good tip. Thanks!

Sorry that my DoF comment was a bit too blanket a statement: was late, OP didn't mention aperture, don't know shooting distance, and was looking on a cell phone. One thing I have noticed that helps with perceived sharpness is high contrast. It is subjective and depends on how close you're looking....but if you're really trying to have critical sharpness: assuming DoF is safe and subject is in focus, it's safer to have less motion blurr with the focal length rule (still true with IS because of higher pixel densities), a lens's wide open aperture is slightly softer then it's optimal (2 or 3 stops down). A zoom lens is also slightly softer at maximum focal length.

Looking at LJ3Jim's crop: it looks good by itself. Another great tool we have now is software. Photoshop has some really great sharpening tools now. It can be used if you are about pixel peeping and trying to get those individual strands sharper:

gjl711 wrote in post #19005364
It's not a rule, it's a guideline and applicable to handheld shots without IS. IS changes things quite a bit. I would think that the formula needs to be update. Something like this.

(Shutter speed = 1/ Focal length) / (2 to the power of the IS capability of the lens).

As the 60-600 has a 4 stop IS, it should be SS = (1/600) / (2^4) or in camera terms, SS= 750 / 16 or roughly 1/60th as a minimum so 1/250 or 1/500 should be fine assuming that IS was on.

Α 'rule of thumb' IS a guideline. Nobody will give you a ticket if you break someone's rule of thumb (unless you break his actual thumb...).

All I am pointing out is that you don't want to be at the ragged edge (of the 'rule of thumb') when you try to do calibration work. Personally, I would switch IS to OFF when doing calibration (AFMA) work, and use a tripod and a remote.

Anyone that uses a shutter speed less than the 'rule of thumb' relying on the IS for camera motion while doing AFMA is asking for trouble.

Your mileage may vary...

MakisM1 wrote in post #19005833
Α 'rule of thumb' IS a guideline. Nobody will give you a ticket if you break someone's rule of thumb (unless you break his actual thumb...).

All I am pointing out is that you don't want to be at the ragged edge (of the 'rule of thumb') when you try to do calibration work. Personally, I would switch IS to OFF when doing calibration (AFMA) work, and use a tripod and a remote.

Anyone that uses a shutter speed less than the 'rule of thumb' relying on the IS for camera motion while doing AFMA is asking for trouble.

Your mileage may vary...

Agree. I use beanbag and remote shutter for such tests. If hand holding a 600 I would use 1/2500 sec or faster with IS/OS off. If not enough light for that fast wait until there is or use beanbag and remote or timer. Then you can be confident results are worthwhile.

MakisM1 wrote in post #19005833
Α 'rule of thumb' IS a guideline. Nobody will give you a ticket if you break someone's rule of thumb (unless you break his actual thumb...).

All I am pointing out is that you don't want to be at the ragged edge (of the 'rule of thumb') when you try to do calibration work. Personally, I would switch IS to OFF when doing calibration (AFMA) work, and use a tripod and a remote.

Anyone that uses a shutter speed less than the 'rule of thumb' relying on the IS for camera motion while doing AFMA is asking for trouble.

Your mileage may vary...

When I did my MFA my IS was on and on a tripod with remote. I like the shingle idea to use for MFA.

I think I am going to shoot some more stuff and check my results before I start messing with the MFA again. I am up to the Sax-Zim Bog now in hopes of photographing some more owls. My first day didn't go to well.