hatch1921 wrote:
If this has been mentioned, forgive me and ignore... if not... might help?
I found having the full time DMF switched on, all the time, caused me to miss more shots than I'd like to remember. The AF is so smooth (at least on my copy) that I was bumping it while shooting and the OOF shots stacked up. I turned it off, added a lens coat and dampened down the AF ring, no more issues. It's been a great lens ever since. I don't know if this is what is impacting your shots, but maybe consider giving it a try if you haven't already.
I have the same issue with this lens on my A7R6. Both are new to me and I am new to Sony, so still learning the ins and outs of the menu AF options.
All that said, I have netted it down to environmental conditions or motion or both. My lens is sharp across the range and impressively so even over the A7R6 even wide open. F9 and f10 at 800mm show a tiny bit more contrast, but essentially insignificant. For whatever reason, if it’s hotter and over water, my combo slightly front focuses. I’ve tried all the OS options including off, tripod and hand held. DMF off. If the subject is moving, it seems to slightly back focus usig OS 2 or 3, but slightly front focuses at 1. In more normal conditions on a perched bird it locks on fine. On a moving bird, f9 makes no difference, but f10 and OS 3 seem to improve things as does setting the AF lock sensitivity up 1 from standard 3 to 4. Even then, results are erratic, maybe a 1 in 10 hit rate.
I think there is a pdaf incompatibility issue. There is also precious little DoF at 800mm and typical bird distances even at f8, 9 and 10. My guess is it’s due to a too lenient pdaf contrast acceptance protocol in the camera, probably due to pixel pitch. Hopefully a FW update will be able to address this. I like the lens and the camera, but it’s not a reliable combination as it sits.
Do u have a sample that's really sharp (perched). I didn't get a single shot thst I was happy with. Two pieces in a raw. So I'm reluctant to try it again even though 400-800 is THE bird photography range.
Jack Flesher wrote:
I have the same issue with this lens on my A7R6. Both are new to me and I am new to Sony, so still learning the ins and outs of the menu AF options.
All that said, I have netted it down to environmental conditions or motion or both. My lens is sharp across the range and impressively so even over the A7R6 even wide open. F9 and f10 at 800mm show a tiny bit more contrast, but essentially insignificant. For whatever reason, if it’s hotter and over water, my combo slightly front focuses. I’ve tried all the OS options including off, tripod and hand held. DMF off. If the subject is moving, it seems to slightly back focus usig OS 2 or 3, but slightly front focuses at 1. In more normal conditions on a perched bird it locks on fine. On a moving bird, f9 makes no difference, but f10 and OS 3 seem to improve things as does setting the AF lock sensitivity up 1 from standard 3 to 4. Even then, results are erratic, maybe a 1 in 10 hit rate.
I think there is a pdaf incompatibility issue. There is also precious little DoF at 800mm and typical bird distances even at f8, 9 and 10. My guess is it’s due to a too lenient pdaf contrast acceptance protocol in the camera, probably due to pixel pitch. Hopefully a FW update will be able to address this. I like the lens and the camera, but it’s not a reliable combination as it sits. ...Show more →
Jemini wrote:
Do u have a sample that's really sharp (perched). I didn't get a single shot thst I was happy with. Two pieces in a raw. So I'm reluctant to try it again even though 400-800 is THE bird photography range.
I do. Nothing exciting or artistic, basically test shots. I’ll post a few as soon as I can get to my computer.
Jemini wrote:
Do u have a sample that's really sharp (perched). I didn't get a single shot thst I was happy with. Two pieces in a raw. So I'm reluctant to try it again even though 400-800 is THE bird photography range.
Traditionally 800 mm lenses cost in the $13k-$20k range. Even the Nikon 800/6.3 is really inexpensive for what it is, just 1/3 slower, and maybe a bit less in the optical quality department than the f/5.6 versions, and the Sony 400-800 is half of the price of the PF Nikon lens. I would think it'd be pretty shocking if there were no compromises at the price it's offered. That said, as a Nikon user I would like to see a comparable zoom that goes to 800 mm offered for the Z mount in the future. I live in Finland where the light is more often quite subdued compared to more Southern latitudes, but I can't imagine using a fixed 800 mm lens due to the challenges in finding the subject in the viewfinder in the first place, and when the subject comes too close, what can one do? Switch to a shorter lens, brilliant, so a lot to carry. In any case 800 mm while it is now more accessible and popular than before, it's still in the exotic territory where the best quality comes with a significant price.
It does seem people are still very keen to chase the long focal lengths and higher quality, despite the difficulties.
Jemini wrote:
I didn't get a single shot thst I was happy with. Two pieces in a raw. So I'm reluctant to try it again even though 400-800 is THE bird photography range.
I just returned my third copy of this lens. It is the perfect focal length range for birds, but I never managed to get any images I was really happy with - although if all you want is something to post to social media, it's an okay lens.
Here are some images from my combo taken yesterday. These were both hand-held, A7R6 in M mode with auto ISO, 1/1000th at f8 through f13. Processed in ACR>PS. Keep in mind I am new to this system, body and lens so still definitely learning its and my own shortcomings. I was playing with aperture, AF modes, etc as well. Also note, all sized to 2048px, so view accordingly as this site browser magnifies. Full frames then crops.
I realize these may not satisfy the more demanding bird photographer, but I honestly didn't expect even this much from a zoom of this nature, especially over the 67mp sensor. If I were demanding AND wealthier, I would spring for the 600 and 1.4x
I am somewhat surprised the eye AF saw the small bird's eye in its own shadow.
Also, I remain convinced that both atmospherics and pixel pitch are affecting the PDAF's abilities. I think we need a camera FW update to deal with higher magnification lenses. IDK if it's too much or too little contrast, or too shallow DoF that is affecting it, or possibly both.
ILCE-7RM6FE 400-800mm F6.3-8 G OSS lens800mmf/8.01/1000s1000 ISO+0.7 EV
ILCE-7RM6FE 400-800mm F6.3-8 G OSS lens780mmf/13.01/1000s640 ISO+0.7 EV
Again, captured using my first and only copy of the lens....
Yours are way better than mine!
I suspect the A1ii's AF is better suited to this lens, or you may have a notably better copy than mine.
I had maybe ten or so usably sharp frames out of a couple hundred, so I realize there is definitely a problem with my particular combo of some sort. Either the lens can't keep up with the A7R6 AF readout, or something else in the chain is foiling it, or perhaps even it is the lens isn't resolving enough to properly activate and keep AF engaged. I remain hopeful Sony will address it with revised FW for either cam or lens or both.
PS: I also note your shutter speed. I never went that high. Perhaps it is an OS issue?
p.3 #10 · Sony 400-800 Poor AF accuracy at 800 f/8
Jack Flesher wrote:
Yours are way better than mine!
I suspect the A1ii's AF is better suited to this lens, or you may have a notably better copy than mine.
I had maybe ten or so usably sharp frames out of a couple hundred, so I realize there is definitely a problem with my particular combo of some sort. Either the lens can't keep up with the A7R6 AF readout, or something else in the chain is foiling it, or perhaps even it is the lens isn't resolving enough to properly activate and keep AF engaged. I remain hopeful Sony will address it with revised FW for either cam or lens or both.
PS: I also note your shutter speed. I never went that high. Perhaps it is an OS issue?...Show more →
The target was stationary, at least semi-stationary, so, the AF aspect of the combo didn't matter much, if any. That lens is as sharp using the A7r VI but no real life images I can post yet with that body though. I may add that the system was on a tripod with gimbal head, so, that and the high shutter speed did minimize any blurriness due to camera/lens movement.
p.3 #11 · Sony 400-800 Poor AF accuracy at 800 f/8
AGeoJO wrote:
The target was stationary, at least semi-stationary, so, the AF aspect of the combo didn't matter much, if any. That lens is as sharp using the A7r VI but no real life images I can post yet with that body though. I may add that the system was on a tripod with gimbal head, so, that and the high shutter speed did minimize any blurriness due to camera/lens movement.
I need to revise my above comments a bit. In going back through my images from Thursday, I had a significantly higher proportion of eyes sharp images when my camera was on the gimbal and tripod. My gut is now telling me it’s more likely an OS/shutter speed/stability issue. I’m going to up the SS next outing and couple it with various AF and OS settings.
I found a handful of this pigeon which I shot as he was doing the head-bob and strut thing as I was getting ready to put the gear back in my trunk. Almost all were good focus on the eye, albeit with a tad bit of front or rear focus depending, at least as noted by the feather detail. I was on the gimbal and using 1/1600th. My current theory is now more an OS/IS issue. 1/2500th may just be the answer. I hope to have time to test further next week.
ILCE-7RM6FE 400-800mm F6.3-8 G OSS lens800mmf/8.01/1600s320 ISO0.0 EV
p.3 #12 · Sony 400-800 Poor AF accuracy at 800 f/8
Jack Flesher wrote:
I need to revise my above comments a bit. In going back through my images from Thursday, I had a significantly higher proportion of eyes sharp images when my camera was on the gimbal and tripod. My gut is now telling me it’s more likely an OS/shutter speed/stability issue. I’m going to up the SS next outing and couple it with various AF and OS settings.
I found a handful of this pigeon which I shot as he was doing the head-bob and strut thing as I was getting ready to put the gear back in my trunk. Almost all were good focus on the eye, albeit with a tad bit of front or rear focus depending, at least as noted by the feather detail. I was on the gimbal and using 1/1600th. My current theory is now more an OS/IS issue. 1/2500th may just be the answer. I hope to have time to test further next week. ...Show more →
Jack, while I like Capture One for most of my photography, I think DxO Photolab does a particularly good job on birds and wildlife. The DeepPRIME XD3 denoising and Lens Sharpness Optimization tools in Photolab (all with the default settings) can make a significant difference to what you are getting from this lens. If you are open to this, get a test copy of DxO PL9, open your raw files, select from the Presets: DxO Optical Correction Only, then click/enable (if not enabled in the Preset) the DeepPRIME XD3 denoising and Lens Sharpness Optimization. There should be no need for any manual adjustments except exposure.
p.3 #13 · Sony 400-800 Poor AF accuracy at 800 f/8
ruthenium wrote:
Jack, while I like Capture One for most of my photography, I think DxO Photolab does a particularly good job on birds and wildlife. The DeepPRIME XD3 denoising and Lens Sharpness Optimization tools in Photolab (all with the default settings) can make a significant difference to what you are getting from this lens. If you are open to this, get a test copy of DxO PL9, open your raw files, select from the Presets: DxO Optical Correction Only, then click/enable (if not enabled in the Preset) the DeepPRIME XD3 denoising and Lens Sharpness Optimization. There should be no need for any manual adjustments except exposure....Show more →
I will take a look for sure -- thanks for suggesting this!
