AF fine tune (1 Viewer)

[shrek48]

I am about to try to Fine tune my D7200 to my Sigma 150-600 c lens. Watched a few videos but still have a few questions I hope you can help with... Any replies must be idiot proof please , I am not camera savvy ;-)
Most of my pictures (99.9%) are at 600mm so;-
Do I set up the AF fine tune test at 600mm ?( full zoom)
In AP mode ??
At F 6,3 ( I think that is my lens lowest F value??
Any other advise in layman's terms would be awesome please
TIA

 

[seaspirit]

With the Sigma 150-600 being one of the lenses supported by Sigma's lens dock and tuning software the most obvious advice is to invest into the lens dock. This will allow you to tune the lens AF at several focal lengths and for several distances. Somewhat time consuming but worth it.
AF-tuning is done wide open (in your case d/6.3 @ 600 mm) and at a distance of appox. 10 meters for a 600 mm lens if you restrict yourself to the in camera tuning. Use the center AF point and S-mode with the rig mounted on a stable tripod.
You will need good light and a high contrast focus target with a way to judge for front/back focus. Plenty of those can be found online for a DIY solution. Look at a few you can buy and you will see that this can be rigged up easy with a ruler.
Rather spend the money on the dock than on buying a lens calibration target.
Take several shots - re-focussing everytime - as there will be some variability and pick a happy medium.

 

[shrek48]

With the Sigma 150-600 being one of the lenses supported by Sigma's lens dock and tuning software the most obvious advice is to invest into the lens dock. This will allow you to tune the lens AF at several focal lengths and for several distances. Somewhat time consuming but worth it.
AF-tuning is done wide open (in your case d/6.3 @ 600 mm) and at a distance of appox. 10 meters for a 600 mm lens if you restrict yourself to the in camera tuning. Use the center AF point and S-mode with the rig mounted on a stable tripod.
You will need good light and a high contrast focus target with a way to judge for front/back focus. Plenty of those can be found online for a DIY solution. Look at a few you can buy and you will see that this can be rigged up easy with a ruler.
Rather spend the money on the dock than on buying a lens calibration target.
Take several shots - re-focussing everytime - as there will be some variability and pick a happy medium.

Thank you for that , very interesting and will look at a dock .

 

[gerald762]

To avoid any shake with the camera, use a tripod and use the shutter timer. This allows any vibration to disappear by the time the shutter fires.

 

[MikeInPA]

If 99% of your photographs are at 600mm I wouldn’t bother with the USB unless you can get one cheap. The advice you’ve been given so far is all sound. The LensAlign is a pretty good tool for AF Fine Tuning. Make sure your mount is sturdy and don’t try and estimate the results from the camera, download them and check on the computer.

 

[shrek48]

I bought a cheap Af fine tune card and set it all up, went in increments of 5 as a base setting, luckily + 10 nailed it... lot sharper to my eye, very happy with the results.

 

[njlarsen]

I bought a cheap Af fine tune card and set it all up, went in increments of 5 as a base setting, luckily + 10 nailed it... lot sharper to my eye, very happy with the results.

Is it just me or is the sharpest point the edge of the coconut behind the bird? Mind you, this might be what the camera chose to focus on.

Niels

 

[Acid John]

I'm with Niels either back focusing or focused on the coconut. Check your focus point to see (use single point focus).

 

[nikonmike]

Another one for bringing the focus point forward a fraction

 

[MikeInPA]

I bought a cheap Af fine tune card and set it all up, went in increments of 5 as a base setting, luckily + 10 nailed it... lot sharper to my eye, very happy with the results.

Before you adjust anything check the position of the focus point. It was probably on the coconut. The Nikon software should have an option to display the focus point even if your camera doesn’t.

edit. I see it’s already been suggested.

 

[shrek48]

Thanks guys, excellent feedback, just what I hoped for as my eyes and experience are not great for focusing. I will check and see If I "missed" focus or it is back focusing a bit ;-) thank you .

 

[shrek48]

So on your advice had another look and took it from +10 to +8 , what are ur thoughts please. I tried to focus on the eye when possible but mostly the body of the bird/.

 

[MikeInPA]

Are you photographing through glass by any chance? What settings are you using? Shutter speed, Aperture, Focusing Mode etc.

Edit. Sitting here photographing birds at a feeder through an open window I had the thought to mention that at 600mm you’ll rarely get a sharp image without being on a tripod.

 

[shrek48]

on a tripod, through an open window at 400 F29 or auto depending on my health and mood ;-)

 

[MikeInPA]

on a tripod, through an open window at 400 F29 or auto depending on my health and mood ;-)

Did you really mean f/29? Thats way too much depth of field. There's a lens condition called diffraction where as you go above something around f/11 it tends to blur the image and reduce sharpness. 1/400 should be fine and if you drop down to something like f/7.1 or f/8 the corresponding ISO can be dropped down by a lot which will reduce the noise and that will also help sharpness. By opening up the lens aperture you will allow more light in and yes it will reduce the depth of field but it also blurs the background which looks nicer. In auto mode it's the camera that decides the settings, in Aperture mode A you decide. Set f/7.1, adjust the ISO according to the lighting conditions to achieve a fast enough shutter speed, as you're on a tripod 1/125 should be enough most of the time.

 

[shrek48]

Did you really mean f/29? Thats way too much depth of field. There's a lens condition called diffraction where as you go above something around f/11 it tends to blur the image and reduce sharpness. 1/400 should be fine and if you drop down to something like f/7.1 or f/8 the corresponding ISO can be dropped down by a lot which will reduce the noise and that will also help sharpness. By opening up the lens aperture you will allow more light in and yes it will reduce the depth of field but it also blurs the background which looks nicer. In auto mode it's the camera that decides the settings, in Aperture mode A you decide. Set f/7.1, adjust the ISO according to the lighting conditions to achieve a fast enough shutter speed, as you're on a tripod 1/125 should be enough most of the time.

Thanks, learnt something new again will look at what my max aperture is and try that

 

[MikeInPA]

Thanks, learnt something new again will look at what my max aperture is and try that

I never stop learning. 🤪

Or maybe I relearn something I forgot. 🙄

Another tip. Set AF-C, Continuous Autofocus. Birds are rarely still and AF-C will adjust for these movements. Don’t take just single shots, take loads of shots in a burst. It’s not like film, review and delete images that you don’t like.

 

[shrek48]

I never stop learning. 🤪

Or maybe I relearn something I forgot. 🙄

Another tip. Set AF-C, Continuous Autofocus. Birds are rarely still and AF-C will adjust for these movements. Don’t take just single shots, take loads of shots in a burst. It’s not like film, review and delete images that you don’t like.

Thanks, I am in AF s so will change that too , thank you

 

[seaspirit]

The EXIF for one of the starling images shows:
600 mm, f/29, 1/400 s, and ISO 25600

An f-stop of f/29 has as already mentioned a negative effect on IQ. To judge focus you want to keep the aperture anyway wide open, i.e. @ f/6.3 with your lens. You can do this by using aperture priority on your camera. Then it will keep the aperture you set (f/6.3) and match shutter speed and if set Auto-ISO for correct exposure.

However, an ISO of 25600 is not helping with IQ either. Try to keep it as low as possible, ~3200 should be OK.

1/400s with a 600mm lens is borderline. Faster is better.

Try to get to something like 1/600s, f/6.3, ISO1600 (or lower) for testing.
Now this will require decent light.
To test AF accuracy I would use an artificial target (plush toy) and put it in a well lit spot. That eliminates movement of the subject, and allows to compare different test shots. Remember you want to test your camera/lens so Pooh the Bear works.
Once you confirmed that AF settings are as good as they get you can move on.

UH

 

[nikonmike]

The only way i found that worked for me to fine tune was, use something like a match box @600mm wide open on say short grass, this will indicate how much the focus is out.