p.3 #1 · What's the deal with aperture stopping down during AF?
Fred Miranda wrote:
Sony is been very stubborn to correct this and it makes no sense to me.
I've puzzled over this as well, and I'm forced to conclude/guess that there is some other reason, which Sony has not shared. In my little studio, I was forced to hang an LED light panel overhead, so there's more light for focusing. (I use portable strobes, with no modeling lights)
p.3 #2 · What's the deal with aperture stopping down during AF?
jhinkey wrote:
Seems that at that focal length and f-stop EVERYTHING looks like it's in focus. I know that when I put my 15/4.5 Voigt to f/8 on my A7RII and then use 100% magnification to find best focus it's really really difficult because it takes a lot of focus ring turning to see a difference. At f/16 diffraction has taken a firm hold knocking off the sharpness that the AF system needs to find the best focus.
If found similar things with the 18-35G on my D800 - stop it down even in bright daylight and the AF system has trouble getting accurate focus....Show more →
John, the more I think about it the more inclined I am that it has to do with just the AF issues at smaller aperture settings and less with the focus shift at all. Furthermore one would indeed think that the DOF at f/16 using a 25mm lens would be sufficient to render quite a bit of zones in focus. But take a look at the images below. These are crops of 3 different images.
Image 1: I was using another lens at wide open previously and when I put the Batis 25mm on, I didn't think much about it and took this image at f/2. No problem with the focus but not enough DOF and the sunstar of the sun was not defined at all.
Image 2: Stopped down to f/16, and the AF issues struggled. I could see in the viewfinder/monitor that it flickered and the green button didn't turn on. I went ahead an took this shot since I really wanted to see the result. Well, nothing is in focus.
Image 3: I opened up the aperture to f/8, got AF right away. The green button is on and the EVF was not flickering at all. I stopped it down to f/16 and took the image. I am not worried about any diffraction issues at all. I just wanted to get the sunstar and in my experience, diffraction although maybe visible on charts but in real life shooting, a slight decrease in resolution turns out to be negligible. Again, these are all crops and you can see the full image of the 3rd image in the link I provided above.
p.3 #3 · What's the deal with aperture stopping down during AF?
snapsy wrote:
For stopped-down shooting I imagine the Canon 24-70 w/adapter focuses faster than the native 24-70GM since the A7rII focuses wide-open on the adapted lens. That would get Sony's attention
I wish they would listen to the folks here instead of where they keep getting bad info from some of these other sites. I dare say we are smarter. Flame suit on.
p.3 #4 · What's the deal with aperture stopping down during AF?
snapsy wrote:
For stopped-down shooting I imagine the Canon 24-70 w/adapter focuses faster than the native 24-70GM since the A7rII focuses wide-open on the adapted lens. That would get Sony's attention
It depends on the actual aperture used and the lighting conditions, I would say but I get your drift....
p.3 #5 · What's the deal with aperture stopping down during AF?
MikeEvangelist wrote:
I've puzzled over this as well, and I'm forced to conclude/guess that there is some other reason, which Sony has not shared. In my little studio, I was forced to hang an LED light panel overhead, so there's more light for focusing. (I use portable strobes, with no modeling lights)
I remember finding a workaround by shooting in "P" mode. I don't remember the specifics but it was posted in a thread about it...
p.3 #8 · What's the deal with aperture stopping down during AF?
snapsy wrote:
According to this post from a dpreview editor, Sony is doing this to reduce shutter lag.
How good is to have less shutter lag if it takes longer to achieve focus?...Even if all these explanations have a merit, give us the option to make our lenses open up during focus acquisition as a menu option.
p.3 #10 · What's the deal with aperture stopping down during AF?
Heck i can deal with shutter lag myself. See this is a classic case of Sony trying to protect the end user . I don't want them to be doing that. You cripple the camera where we don't have options.
p.3 #11 · What's the deal with aperture stopping down during AF?
Fred Miranda wrote:
How good is to have less shutter lag if it takes longer to achieve focus?...Even if all these explanations have a merit, give us the option to make our lenses open up during focus acquisition as a menu option.
Agreed. And the dpreview editor made that same point. It must be very sunny in Japan
p.3 #12 · What's the deal with aperture stopping down during AF?
OK, guys, I put my Batis 25mm back on and I did some more testing. Steve, this is partly to answer your question regarding the MF option using the Batis. The following is what I observed:
1. When stopped down to, let's say, f/16, the camera doesn't open up the aperture when switched to MF.
2. When stopped down to whatever aperture setting on the camera, the physical aperture of the lens does get stopped down but when I pushed my back AF button, the aperture opens up briefly, the camera focuses, the AF confirmation is lit or beeps and then it closes down immediately. This goes both in AF-S (the beep and lit AF confirmation) or in AF-C (showing the two-lined box) but depending on the aperture and lighting conditions, I noticed that the EVF flickered a little bit. But this is great because that is what the AF system is supposed to do. And I did it indoors while my real-life attempt was outdoors where the sun was still out although it was in the composition. Or maybe this could be the cause, the sun and the busy scene confused the camera/lens the other day. Who knows! At any rate, I feel a little better and more relieved now .
3. I tried all lenses in my lineup and here is the result - all 3 Batis lenses, FE 28mm f/2, FE 35mm f/1.4, FE 55 f/1.8 and FE 90mm f/2.8 G Macro open the physical aperture either fully or close to be fully for AF and closes down immediately after the focus has been achieved.
4. The physical aperture of all GM lenses and Sony FE 50mm f/1.4 remains close and at low lighting conditions, the AF is noticeably slower relative to that of the other lenses.
So, it looks like the FW of those lenses is the controlling factor and not the camera. I am sure that the camera can be also tweaked to behave differently depending on the lens, I guess.
p.3 #13 · What's the deal with aperture stopping down during AF?
I honestly think your camera got confused the other day. Just to much surrounding subject in that scene. It's like shooting water it just can't get a read .
p.3 #16 · What's the deal with aperture stopping down during AF?
GMPhotography wrote:
I honestly think your camera got confused the other day. Just to much surrounding subject in that scene. It's like shooting water it just can't get a read .
Guy, I started to believe that that was the case. Yes, it was a fluke, in other words. And yes, that makes me feel better.
GMPhotography wrote:
Number 4 is bugging me. I hate to be negative as that's not me but that needs to change today with firmware
Understandably so. But again, as long as it focuses, I am OK with it and again, it happens only from time to time and then mostly in the studio.
p.3 #17 · What's the deal with aperture stopping down during AF?
Just wondering if people are contacting Sony about these focus issues. I emailed them quite a while ago about it. Also if anyone knows there local rep maybe they could contact them as well. It's all well and good banging on about it here but it is quite likely that Sony will never see any of it
p.3 #18 · What's the deal with aperture stopping down during AF?
MikeEvangelist wrote:
How odd.
Mike,
Did you try it?
It actually works and shows how the lens should actually operate in the all modes...
So, the steps are:
Set the camera to "P" mode. In the case of the 85/1.4GM, the aperture will default to f/2 in low light. (It never goes larger than that)
Then using the camera aperture dial, change to your desired aperture like f/5.6 or f/8. Set ISO to Auto.
Set the min. shutter speed to a number that will give you a workable shutter speed . **This is the tricky part that does not work like in other modes. Sometimes, if the light is low, you need to set the min. shutter speed to something like "4000" or "8000" to get a shutter speed around 1/125. I know, it's not intuitive. So, you need to play with it until you get an acceptable shutter speed for your shooting.
That's it!
It's better to set AF to AF-S since the aperture will be opening and closing rapidly and that's not ideal with AF-C. You will see that the lens always opens to f/2 during focus acquisition even though the operating aperture is smaller (f/5.6 or f/8 for example). That's how most Sony lenses work anyways... (55/1.8, 35/2.8, 85/1.8, etc.)
It's just an workaround for the limitation imposed by Sony for certain lenses.
p.3 #20 · What's the deal with aperture stopping down during AF?
GMPhotography wrote:
Joshua I'll repeat this as I said before our AF systems rely totally on horizontal lines and not vertical ones. Most folks do not know this
But Guy in one of the Techart PRO threads you wrote:
"Remember focus is best achieved on vertical lines and not horizontal. Always look for a vertical contrast spot to get the best focus. This really is how Sonys work best."
