p.1 #1 · Focusing issues with Sony A7RIV and 200-600mm lens
I’ve been having focusing issues with this combination just like some of you. My photos will be tack sharp for about fifteen minutes of use and then turn to mush. The pictures look as though I had been shooting into severe heat shimmer. Today I noticed how the lens was warm to touch near the program buttons after using it for about fifteen minutes and the photos were all mush. This lens will give perfect focus on my A9 and will not get warm no matter how long I use it. Could the heat I’m feeling on the lens be effecting the outcome of the photos just like heat shimmer does? An electric motor will get hot and will even burn up when it doesn’t receive the right current. Could it be that there isn’t enough amps left for the focus motor from after what the camera uses and this is why the lens gets warm? I’ll get perfectly focused phots after letting the lens cool down for about an hour and then it’s back to getting mush again when the lens gets warm. Is anyone else’s lens getting warm about the time you start getting out of focus pictures?
at any rate, i can't see how it would heat up with only the a7riv, perhaps you are using it in a different manner than how you use the a9ii?
i shoot sports and some bif with the 200-600, i'm holding the bbaf down quite a bit, which i guess would be the worst-case scenario... maybe the only thing worse would be racking the af from mfd to infinity, over and over.
p.1 #5 · Focusing issues with Sony A7RIV and 200-600mm lens
Thanks for the info on the focusing motor. Both cameras were used at the same exact set up photographing hawks feeding their chicks at the nest. The photos turned to mush after the lens got warm on the 7RIV and are all perfectly focused on the A9 since the lens doesn’t get warm on this camera. The lens is warm to touch on the outside and is most certainly much warmer on the inside. Others have also commented in the past about this lens getting warm and it was thought to be the in lens image stabilization causing the heat.
p.1 #6 · Focusing issues with Sony A7RIV and 200-600mm lens
I might also add that the lens still gets warm when used on the A7RIV and the photos still turn to mush even with the lens image stabilization turned off. I’m just putting this heat issue out there as a possible reason for our pictures being out of focus and am hoping others will check to see if their lenses are warm to touch about the same time they get out of focus pictures.
p.1 #7 · Focusing issues with Sony A7RIV and 200-600mm lens
Eagle809 wrote:
I might also add that the lens still gets warm when used on the A7RIV and the photos still turn to mush even with the lens image stabilization turned off. I’m just putting this heat issue out there as a possible reason for our pictures being out of focus and am hoping others will check to see if their lenses are warm to touch about the same time they get out of focus pictures.
Thank you for posting this. I don't own the 200-600 but I've been interested in getting one. I wonder if you could try the following. After you shoot with the A7RIV and the photos start to turn to mush, switch to the A9 and see if you can reproduce the issue. You wrote that you get good results again with the A7RVI if you let the lens cool down for about one hour. So as long as you switch to the A9 fairly quickly and assuming that it is really heat that's causing it, you might be able to reproduce mushy images with the A9.
p.1 #8 · Focusing issues with Sony A7RIV and 200-600mm lens
Thank you lcrs. Will try what you suggested this coming weekend and then report back with the results. It really is a sharp lens, but not so much on the A7RIV for some of us.
p.1 #10 · Focusing issues with Sony A7RIV and 200-600mm lens
Eagle809 wrote:
Thank you lcrs. Will try what you suggested this coming weekend and then report back with the results. It really is a sharp lens, but not so much on the A7RIV for some of us.
Thank you, Eagle809. It will be great if you could report back.
p.1 #11 · Focusing issues with Sony A7RIV and 200-600mm lens
Eagle809 wrote:
Thank you lcrs. Will try what you suggested this coming weekend and then report back with the results. It really is a sharp lens, but not so much on the A7RIV for some of us.
How much shooting do you have to do before feeling the heat? Asking because I want to try this out. I will need to take off my lens coat cover and see if I can notice anything but I want to have an idea of how long I need to be shooting for and how actively I need to be shooting to maybe feel the heat.
p.1 #12 · Focusing issues with Sony A7RIV and 200-600mm lens
Is it really the lens heating up or the body? Now that this thread has me thinking about heat, I noticed the front of A7r IV and back of Tamron 70-180, was much warmer than I would have expected.
Does A7R IV sensor heat up mount area of lens more than other bodies?
p.1 #13 · Focusing issues with Sony A7RIV and 200-600mm lens
Arbitrage, thank you for responding. I was photographing a red tail hawk family at the nest located less then 50 yards away. Camera was set to CAF with small flexible spot in early morning sunshine and an air temp of lower fifties. I was also shooting in low burst mode and the first set of six images were in perfect focus. I then took another burst of nine images about ten minutes later when the male hawk came back to the nest with a meadow vole and less then half of these photos were in focus. I then took another burst of five images less then five minutes later of the female feeding the vole and all of these photos were mush. This is is when I noticed the lens being warm to touch between the tripod collar and the program buttons. I’ve had these focusing issues from day one and bought both of them the minute they became available to purchase. Your should be able to feel the lens getting warm in about fifteen minutes of use if yours is in fact getting warm.
p.1 #15 · Focusing issues with Sony A7RIV and 200-600mm lens
Today I immediately mounted the lens on the A9 after it had gotten warm on the A7RIV like member lcfrs suggested. I then did a ten shot burst and all ten were mush just like on the A7RIV. The kind of mush you would get by photographing a person standing behind a wall of flames 20ft high. The lens is warm to touch on the outside, but certain to be hot on the inside. The heat waves coming from the lens are being picked up by the sensor and thus the reason for the pictures being mush. I then remounted the lens on the A7RIV after it had cooled off, set the camera to record small jpegs and took 500 pictures of various targets at different distances. The lens never got warm and all five hundred pictures were in perfect focus. Setting the camera to record medium and large jpegs resulted in the lens getting warm after about fifteen minutes and all of the pictures being mush again after getting warm. The seven electricians I work with said an electric motor will get hot from using more amps when its being fed less then the required voltage. The double focusing motors found in the 100-400mm and the 600mm lens have different voltage requirements then the single focusing motor found in the 200-600mm lens. The A7RIV is meeting the voltage requirements on these two double motored lenses and not meeting the requirements on the 200-600mm lens. Sony knows they have an issue with this combination and working on a fix, but still happily taking peoples money for their defective product. The fix will have the required voltage for the single focusing motor in the 200-600mm lens after what the camera uses to record medium, large or raw and it will be named A7RV.
p.1 #18 · Focusing issues with Sony A7RIV and 200-600mm lens
I think the correlation of electro-mechanical functions and related heat dissipation makes perfect sense to me. I am speculating further to say the overheated single motor drive may not be capable to operate accurately after a certain heat threshold is exceeded.
Has anyone looked at whether the use of AF-C, AF-S or DMF makes a difference? So far all the A/B testing was done using different camera bodies, but the amount of focusing work each camera does might differ. Perhaps there is a subtle difference of focusing behavior between AF-C on the R4, versus R3/A9/A7 models, causing the R4 to provide insufficient power the single drive?
Does this happen with AF-S or for "back-button" focus configurations?
Single motor drive operations may be more impacted by electrical deviations and lower heat tolerances.
p.1 #19 · Focusing issues with Sony A7RIV and 200-600mm lens
I abandoned the A7R IV and went back to my A7 III
The 200-600 is fine on the A7 III
Aug 12, 2020 at 03:24 PM
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p.1 #20 · Focusing issues with Sony A7RIV and 200-600mm lens
Eagle809 wrote:
Today I immediately mounted the lens on the A9 after it had gotten warm on the A7RIV like member lcfrs suggested. I then did a ten shot burst and all ten were mush just like on the A7RIV. The kind of mush you would get by photographing a person standing behind a wall of flames 20ft high. The lens is warm to touch on the outside, but certain to be hot on the inside. The heat waves coming from the lens are being picked up by the sensor and thus the reason for the pictures being mush.
i doubt that there are any heat waves inside a camera lens:
"Heat distortion is caused when light is refracted through air of differing densities. Hot air is less dense than cold air, so light waves are bent differently in hot versus cold air. The result is visible heat waves when there is a significant temperature difference between the ground and the air above it." https://muenchworkshops.com/blog/heat-distortion-can-ruin-photos-taken-with-a-zoom-lens
Eagle809 wrote:
The seven electricians I work with said an electric motor will get hot from using more amps when its being fed less then the required voltage.
1) you didn't prove that the focus motor is getting less voltage than it's rated at, that's just idle speculation.
2) afaik no one else is having issues with the lens getting hot, you should have returned it or sent it in for service.
