Focus wont stop working when shooting macro(video to show problem).

[Issue]

Hello.

I have a problem with focus when shooting macro.

Im shooting with A6500 and i recently started with macro. I got the Zeiss 50/2.8 macro lens.

Problem is with focus on smaller apertures. Up to about f11 there is no problem but smaller than that, it will “jiggle” around the focus area for 1-2seconds before it stops(if I’m holding same distance to subject).
When diving it is almost impossible to have the same distance so this “jiggling”(i dont know what to call it) will start over all the time and never stops. So this gives me no other option than to just shoot and hope focus is at the right spot, often it is not.

If you look at this video you will probably see what i mean. When diving it looks even worse. Is there any setting that can prevent this, or make it less? Is the lens alright?


Thanks in advance!

 

[Boaty McBoatface]

"Normal."

Not enough light is getting to the sensor to focus reliably. Every camera/lens/scene combo has a point beyond which the AF doesn't work. I think you'll find that if you stop down the lens in a dim room only barely enough to make this effect happen and then go to a bright room using the same settings the camera will focus (on most subjects with detail, anyway).

Some cameras try to get around this problem by opening the aperture for the camera to focus and then stopping the lens back down to take the shot. This helps the AF, but the problem is that lenses often focus differently at different apertures (called "focus shift"). So, you got the camera to lock focus, but when the shutter opens it's no longer focused correctly. Sony's philosophy has been that focus accuracy matters, so historically most of their lenses have had "stopped down focusing" whereby the lens is focused at the actual shooting aperture. Some DSLRs circumvent this by focusing off the mirror, but that introduces other focus errors and micro adjustments, and in any event E-mount Sonys don't have mirrors, but that was the idea behind the Sony's legacy A-mount.

First thing to do is make sure you're running firmware 4.0 on your a6500. Sony made some updates in precisely this area about 3 months ago, and some lenses now have a compromise stopped down focusing behavior (partially opened on certain lenses). That Touit 50/2.8 is an old lens, though, and not made by Sony, so I'm not sure you'll see an improvement, but it's worth a try.

Second, make sure you're Touit 50 has firmware 2.0. It almost certainly does -- 2.0 came out a long time ago. If it doesn't, bummer, because you have to send those lenses to Zeiss for any upgrades. Probably wouldn't change this behavior, either.

Third, your can use a different lens that doesn't focus stopped down.

Fourth, get some kind of focus light to help the AF lock on in low light. The AF light on your camera is probably blocked by your housing, but if it's not make you've set it on Auto in the settings menu.

Fifth, change focus area modes to either Expand Flexible Spot or wide. Those modes give the camera more liberty to go looking for something to go focus on (possibly not what you wanted focused, but your depth of field is pretty high here).

Or lastly, just don't try to AF your 50 at f11, a point at which I'd expect most cameras to run into trouble.

Hope something in all this helps you.

 

[Issue]

"Normal."

Not enough light is getting to the sensor to focus reliably. Every camera/lens/scene combo has a point beyond which the AF doesn't work. I think you'll find that if you stop down the lens in a dim room only barely enough to make this effect happen and then go to a bright room using the same settings the camera will focus (on most subjects with detail, anyway).

Some cameras try to get around this problem by opening the aperture for the camera to focus and then stopping the lens back down to take the shot. This helps the AF, but the problem is that lenses often focus differently at different apertures (called "focus shift"). So, you got the camera to lock focus, but when the shutter opens it's no longer focused correctly. Sony's philosophy has been that focus accuracy matters, so historically most of their lenses have had "stopped down focusing" whereby the lens is focused at the actual shooting aperture. Some DSLRs circumvent this by focusing off the mirror, but that introduces other focus errors and micro adjustments, and in any event E-mount Sonys don't have mirrors, but that was the idea behind the Sony's legacy A-mount.

First thing to do is make sure you're running firmware 4.0 on your a6500. Sony made some updates in precisely this area about 3 months ago, and some lenses now have a compromise stopped down focusing behavior (partially opened on certain lenses). That Touit 50/2.8 is an old lens, though, and not made by Sony, so I'm not sure you'll see an improvement, but it's worth a try.

Second, make sure you're Touit 50 has firmware 2.0. It almost certainly does -- 2.0 came out a long time ago. If it doesn't, bummer, because you have to send those lenses to Zeiss for any upgrades. Probably wouldn't change this behavior, either.

Third, your can use a different lens that doesn't focus stopped down.

Fourth, get some kind of focus light to help the AF lock on in low light. The AF light on your camera is probably blocked by your housing, but if it's not make you've set it on Auto in the settings menu.

Fifth, change focus area modes to either Expand Flexible Spot or wide. Those modes give the camera more liberty to go looking for something to go focus on (possibly not what you wanted focused, but your depth of field is pretty high here).

Or lastly, just don't try to AF your 50 at f11, a point at which I'd expect most cameras to run into trouble.

Hope something in all this helps you.

Thanks for this awesome answer!

I will check my versions on both my a6500 and lens. Both should be updated as I did the camera few weeks ago and lens is new. But I will check anyway.

Unfortunately a different lens is not an option. Mostly because I already bought this and a port. But also because Nauticam does not support all lenses and this is the only option they support that will work for my setup.

About focus light, I use 1-2 Bigblue VL5800 for that. I thought this was way more than needed so I have been running them on low for most of the time. I will try to set them on high next time and see if that makes any difference!

I will also try to work with expand flexible spot. I did try it yesterday without luck but I will give it another go in water.

f11 is already very short focus depth when shooting macro/supermacro. I want to go even higher to be honest. I don't have manual focus on this lens but I can lock the focus and try to adjust it with distance maybe. Will not be easy but it might be better than now where I have to shoot and just hope it hits the right spot.

Again, thanks! Appreciate your long answer!

 

[Ricardo V.]

Issue,
Great suggestions from @Boaty McBoatface. Thank you!
A focusing light is a must. I would suggest using a red light just for focusing. I'm unable to recommend proven fixes for the Sony, as I'm not familiar with the system just yet, but for years I've been using a light & Motion Sola 600 focusing light. It has helped me solve just about all focusing problems with a Canon 7D housed in Nauticam. I only use the focusing light when shooting macro. Red light won't affect the image quality, but does let the camera see and achive good focus. The light from the strobes illuminates the area very well and the red from the focusing light does not affect the finished product. This is for blue water conditions. It's going to be different for green water or fresh water dives.

I've tried a Bigblue light set to red too, but the output is too bright and it's just too much and while red is accordingly to wildlife experts, not perceived by many underwater critters, I found that with the Sola 600 that it's soft red gives it just the right amount of light to help the system attain and keep focus without distracting the subject. Again, this is for blue water conditions.

Back when I got the Nauticam, the folks that I bought it from recommended use of a focusing light. I ignored that for a while and was just super frustrated with the investment until I researched some more and sure enough, the camera needs light to see and the sola fit the bill.

Having manual focus also helps tremendously, particularly during low light conditions when're the red light brings me very close, but not there, so I manually override to attain focus. This happens when dark subjects are in front of dark backgrounds. The camera has a harder time focusing, so manually you can hone in to achieve tack sharp focus.

I'm not sure if you have considered back button focusing instead of pressing the shutter button half way. From your video, it seems as you have already done so... if not, consider going with back button focus. It's proven to be a preferred way of working underwater for many folks and that's been the case with me.

In closing, I recently got a Sony 50 mm lens and did a few top side test shots in low light and got frustrated with the focusing lag time and the hunting, so after reading some comments and suggestions, went ahead and upgraded the firmware. It made a big difference and the lens is out performing many times over its initial capability. I did this about 2 weeks ago.

I'm still new to Sony, but soon will be experimenting with the setup and will let you know if there is a better or a preferred focusing setup to configure the system in order to get a higher success when taking macro shots.

Lastly, I would suggest trying this when shooting Macro... set your Focus mode to DMF, and turn on your Focus Peaking to High. This will let the system autofocus, and also will let you override it manually. I'm impressed with the peaking feature and believe it has the potential to help underwater. Again, I've not tested that but topside only.

I get that your specific configuration does not have a manual focus gear, but if this works when you are doing your topside test, then you will have a better comfort level prior to investing in a new port with focusing gear that will let you manually adjust and override focus. Give it a try and see if that helps.

Please let us know if the DMF, focus peaking and back button features help.

Cheers,
Ricardo

 

[Boaty McBoatface]

I read the OP's reply and immediately thought of DMF. Then I saw Ricardo V had already done a great job covering it. I shoot in DMF 90% of the time.

However, I would suggest setting focus peaking to Low and changing the peaking color to red. I've found setting peaking to high to be too much of a blunt instrument, personally. If I am shooting a scene where Low doesn't show me enough peaking data (very rare) I bump it to medium. I never use High. But, you may have a different experience. Red, I just find easier to see.

Back to the OP, if it's Macro, setting focus area to Wide, as I suggested earlier, may not be a good idea for a macro subject in the already near the center of the frame.

Others may know better, but I think that using AF for Macro isn't how most people do it. I think that most people fix a manual focus and then move the camera.

PS: I only us my interchangeable lens Sonys above water, but I set them to back button focus, too.

 

[Issue]

Thank you both for your answers!

Lots of information to process and go threw..

About focus light. As I said before I already use two 5800lumen video lights. I use them on low tho, and have not tried red. I will try this and see if it works better. Ricardo you say that red is to strong with Bigblue, this should not be an issue for focusing, right? Only problem is that it might scare wildlife, if I understand you correct?

I checked version in my camera. "Ver. 1.04" on body and "Ver. 02" on lens. That should be the latest. I know you said 4.0 but for my model it should be 1.04. And Ver. 02 on lens should be equal to 2.0?

About DMF. If I understand this function right, it require me to have manual focus which I don't. Zeiss 50 does not have focus gear as far as I know, I will have to double check this again..

While writing this replay I think I might have found a solution. When I was in DMF I tried to focus on stuff well lit up with my phone. Just to see if brighter focus light might help. No difference with more light. BUT. DMF seems to work like AF-S, which I have not used at all. In this mode, camera finds focus and stops much faster compared to AF-C. I will not be able to follow stuff but that might not be a problem for macro.. Woh! Cant wait to try this out in water..

Also, DMF gives me focus peaking WITH auto focus. Something I have been wanting to have for a while.. AF-C and DMF should work in the same way besides focus peaking visible, right?(because I can not touch my focus wheel in uw-house)

 

[Barmaglot]

You can't combine AF-C with DMF - there's logically no way to implement such a mode. In DMF mode, the camera basically dials in a focus and tells you "Here's what I got. You don't like it? - Try to do one better.", at which point you can agree with the camera and take the shot, or turn the focus ring and adjust.

However, in AF-C mode, the camera continuously updates the focus, as it tried to track subjects moving across the frame - there is no point in time where it would tell you "okay, now you try to focus" - at most, it could stop AF-C and switch to AF-S/DMF when you touch the focus ring, but that would simply be confusing. If you want to see where the camera is focusing in AF-C mode, there's already those little green boxes that pop up, indicating which part of the image is currently focused on.

 

[Issue]

You can't combine AF-C with DMF - there's logically no way to implement such a mode. In DMF mode, the camera basically dials in a focus and tells you "Here's what I got. You don't like it? - Try to do one better.", at which point you can agree with the camera and take the shot, or turn the focus ring and adjust.

However, in AF-C mode, the camera continuously updates the focus, as it tried to track subjects moving across the frame - there is no point in time where it would tell you "okay, now you try to focus" - at most, it could stop AF-C and switch to AF-S/DMF when you touch the focus ring, but that would simply be confusing. If you want to see where the camera is focusing in AF-C mode, there's already those little green boxes that pop up, indicating which part of the image is currently focused on.

Sorry i meant to compare AF-S and DMF..
I know how AFC works, that is what i have been using with BBF until now.

Yes AFC is marking that it found focus by turning the focus square green, when i use that focus area setting.

 

[Boaty McBoatface]

DMF = AF-S with a manual override and full time focus peaking.

Ver. 1.04: Yeah, sorry, you just want the latest update from about 3 months ago when Sony adjusted stopped down focusing behavior. On my a7rii it's called 4.0. Sorry for the confusion.

 

[Ricardo V.]

@Issue,
From my personal experience, I've found SOLA lights to be far superior in every way when compared to BigBlue. They used to be expensive, but prices have come down significantly and they are easy to find.

I have a question for you. What type of water are you diving? Is it blue water like we would expect to find in Florida marine environments and across the Caribbean? If so, blue water absorbs "red light" rapidly. The spectrum of "red light" fades away the deeper we go. Other spectrums of color that make up natural light travel further and deeper... essentially blues and some darker greens.

Considering this is the environment where lots of critters live, they don't need nor have had the need to possess an enhanced perception of the color red. I've noticed critter that live in shallower environments like a red lip blennie or Hawkfish will see red light.

1. To get the colors to pop, you need a strobe or an underwater flash. I personally like INON strobes; however, there are several other good manufacturers out there that do a good job producing good quality strobes.

2. The light comes out of the strobe, hits the subject, then travels back to your camera's sensor. The more the light has to travel, the more loss of color occurs. Shorter distance is always better. Remember that ocean water loves to eat color, so the less amount of distance any spectrum of light travels, the more your camera will be able to see, and your photos will turn out much better.

4. When shooting macro, you don't need a lot of light, but you do need a good balanced light with all natural color spectrums so that the subject is illuminated and the camera sensor can capture true color as fatefully as possible. The shorter the distance light travels, the better.

You want to get rid of the water, so get close, very close, as close as possible.
Some rules of thumb:

A. Get close
B. Shoot up
C. Zoom with your fins

When taking photos of subjects that live in blue water, you want to be as stealth as possible. You want them to continue with their regular behavior or to not be disturbed by your presence. If they notice you are there, they are likely to flee, stop doing whatever they are doing and simply go away.

One proven technique is to approach them stealthily and to shine a red focusing light on them, so your camera can focus. It's just for your camera to be able to see. You can see whatever you are shooting too, but not it it's full glorious colors, just enough to lock focus or help the system attain focus.

When you press the shutter release, the strobes fire a flash or light that carries all natural light spectrums, including the precious red light we all want to preserve. The amount coming out of the focusing light is so mild.... assuming you are using a SOLA 600, that it won't affect the finished photo. The sole purpose of the focusing light, of a red focusing light that is... is to let you camera see and enhance its focusing capabilities. You can see as well, enough to adjust or assist your camera if it focuses on the wrong body part, or the wrong spot.

5. Any critter with eyes, or wherever eyes would be expected, focus on that. If the eyes are out of focus, the picture is not going work. Your image viewers won't connect with your subject if the eyes are not in focus. Nudibranchs... focus on the guills- horns or whatever seems to be it's head.

So, the strobe fills and adds all colors back to the shot.

When using a BigBlue light, my personal experience is that it's too bright and it affects the finished product. It also has some harmonic oscillating waves that ruin the shot; therefore, SOLA is the way to go.

The INON z240 strobes also have a focusing light, but it's easer to just use the SOLA or something equivalent.

I'm uploading a photo of both the SOLA 600 and one of my BigBlue lights... side by side and set to red. You can see the output and get a better feel for what I'm talking about.

Take care and talk to you soon,

Ricardo