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Micro Four-Thirds (2 Viewers)
- Thread starter JGobeil
- Start date
DanC.Licks
AKA Daniel Bradley
Weird. I still get just the main page.
https://marketplace.500px.com/?utm_...bpQ&siteID=je6NUbpObpQ-yKjwTkbllBmN3.s1YILlyQ
https://marketplace.500px.com/?utm_...bpQ&siteID=je6NUbpObpQ-yKjwTkbllBmN3.s1YILlyQ
that's weird. it should work.
well, you give me no choice. here are they.
On a duck shot with lots of water dropplets, saw practically no CA at all. Though I did not went over it "forensically", so to speak...
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Tord
Well-known member
Same here, had to lookup cango and take it from there. Nice Kingfishers.
Thanks Tord!
Do you get the same result when clicking on the link on my signature? I go right in. Perhaps you have to be logged in or they have put some restriction.
Tord
Well-known member
The link in your signature works fine.
It's the link with https://marketplace.500px.com/... that is not working.
It's the link with https://marketplace.500px.com/... that is not working.
Tord
Well-known member
Just came home from Sri Lanka.
The 400/5.6 USM + metabones was put to serious field test. I am really pleased with the results (will post later), though I identified two issues with the setup.
At occasion, the AF will refuse to work if it fails in acquiring focus in the first place. The only remedy is to switch camera off/on. Or to focus manually. I missed a few precious shots until I got the feeling when the setup had entered such a state.
Quite often you need to shoot two or three frames to get one with focus spot on. Even after getting AF confirm beep and light, it seems that focus is slightly changes between frames, just a little but enough to turn a great shot into an acceptable one. In many cases though one shot is enough. I would assess the keeper rate is 2 pin sharp out of 3 frames, sometimes 1 only, sometimes 3, but never 0. Strange.
The EM1 IBIS does a great job with this lens. Was able to shoot handheld with shutter times as low as 1/25 s with more than acceptable results. Great for early morning/late afternoon photography.
I also brought the SW80, but the results I got were clearly inferior to the 400, with a few exceptions. Operating it from jeep was hardly feasible, due to the sheer length of the scope. I should have brought the TLAPO804 instead...
JGobeil
Nature Photographer
that's weird. it should work.
well, you give me no choice. here are they.
On a duck shot with lots of water dropplets, saw practically no CA at all. Though I did not went over it "forensically", so to speak...
Nice and sharp. Well done !
JGobeil
Nature Photographer
Hi Tord,
I'm glad you like the 400mm. Like I reported before, I also have the focus problem. I can't rely on focus and a few shots are needed to make sure. I find that quite annoying. It gets worse as you increase distance.
I don't seem to experience the problem you have with focus refusing to work. On occasion at close range, it will hunt endlessly but focusing elsewhere fixes the problem.
IBIS works great on mine also, even with the 1.4X or the 2X TC.
Tord
Well-known member
Hi Carlos,ok. good to know. I won't be trying to take it apart - done that with a previous scope's crayford and f***ed that up, förlåt min franska. Still have the lens cell of a TS scopos 80/560mm triplet apo (so it says) don't remember the f-number though. That one was a splittable tube also. At the time did not know about flatteners and reducers, so did not know what to do with the splittable design
I just recall sending an email to Teleskop Express support, asking about reversing the focuser axis L/R. That was shortly after purchasing the scope >2 years ago and they answered that it is not possible. I had a look at the scope and indeed the placement of the screws is not symmetrical so they seem to be right. The only option left would be to take out the axis and try to reverse it but I failed unlocking the screw that holds the dual speed with moderate force and I don't want to break anything.
What I also did at some point was to rotate the scope 180 degrees. The dual knob ends up at the side you want it to be, learning the knob is on top and not bottom is quite easy to learn but learning that the rotation is reversed is harder... But not impossible. Not sure if it has any impact on the crayford focuser performance.
I won't bother with it. Yes, I did the 180 turn around, and it's a bit awkward, though it works. Not sure how it works handheld.
What will take some use to, is the shallow dof for focusing. I striped down and old OM lens (3d party) to get the helical focuser as well as the diaphragm for stopping down. But the hole was to narrow and not at the right position I guess., so it vignetted quite a bit.
With the scope came a screw on lens lock. Would it be wiser to stop it down there - by cutting a hole, say 70mm? Thus if I have good light, I just could screw it on/off and not worry about vignetting.
Thanks Jules! appreciated.
Tord
Well-known member
The shallow DOF is a blessing and a curse at the same time, isn't it?
Yes stopping down this way will work. My SW80 ED has a lens cap with a perforation that is 1/2 of the diameter, meaning 2F-stops i.e. F/15. I would personally rather manufacture front caps out of cardboard or plastic instead of drilling a hole in the metal lens cap.
DanC.Licks
AKA Daniel Bradley
Better than nothing, but still not the best place to stop a lens down. It does stop it down, but at the cost of resolution. Better to have a diaphragm inside the tube, ideally at the optical node. Hard to do though, and I haven't figured out how. It would have to be pretty far inside, around the end of the focuser.
DanC.Licks
AKA Daniel Bradley
Tord,
I have not experienced and focus refusals. Maybe a contact problem?
I think the camera wants to re-affirm focus with each shot, and that takes a little time. Maybe only a fraction of a second, but still, it seems to want to make sure and that means backing off and going back in. I notice it more in bad light as would be expected. So it is entirely possible that it finds other parts of the image within the small focus area to concentrate on. The tests I have done on a tripod for focus consistency score 10 out of 10. Hand held there is always going to be a little discrepancy.
Last night for fun I put the 2x TC on the 400 and hand held half a dozen shots of the moon, backing off by hand and letting the camera refocus each time. The air was poor, and the fullsih moon offered little detail and contrast. Still, it focused every time. I had focus peaking turned on to double check.
Here is a crop as the whole image is not interesting without shadows:
I have not experienced and focus refusals. Maybe a contact problem?
I think the camera wants to re-affirm focus with each shot, and that takes a little time. Maybe only a fraction of a second, but still, it seems to want to make sure and that means backing off and going back in. I notice it more in bad light as would be expected. So it is entirely possible that it finds other parts of the image within the small focus area to concentrate on. The tests I have done on a tripod for focus consistency score 10 out of 10. Hand held there is always going to be a little discrepancy.
Last night for fun I put the 2x TC on the 400 and hand held half a dozen shots of the moon, backing off by hand and letting the camera refocus each time. The air was poor, and the fullsih moon offered little detail and contrast. Still, it focused every time. I had focus peaking turned on to double check.
Here is a crop as the whole image is not interesting without shadows:
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Tord
Well-known member
Dan,
The experience reminds of the one I had when trying a cheap, China made, MMF copy. Display shows all information, camera will not focus, and shutter cannot be released.
What I found yesterday is that when the camera refuses to focus, gently rotating the body/lens connection seems to fix the issue. I don't recall if it is clockwise or the other way. I am at this stage not 100% confident it is a reliable method since a focus refusal is not something I have been able to consistently trigger, it happens a bit at random. If that method turns out to be a consistent and safe way to remedy the problem then it is likely a contact issue. I don't know about the tolerances for the MB adapter, but I have a feeling that they are larger than the play caused by adding the genuine MMF3 adapter.
It's possible that the camera re-focuses between frames but still I think the OOF is sometimes a bit too much, with single small AF spot and aiming at a relatively flat surface with texture in good light it sometimes results in several cm OOF. Both back and front.
I am thinking of dropping metabones support an email.
Stay tuned...
DanC.Licks
AKA Daniel Bradley
Tord,
have you cleaned the contacts on the lens and adapter? Really sounds like a contact problem to me.
I feel that the construction of the MB is very precise. No issues at all. Everything fits snugly.
Could be your OOF problems are related to the other problem. I haven't had a lot of chances to try it out in the "real world", but so far, I have been quite happy with the accuracy of the AF. But I will definitely keep an eye on it.
have you cleaned the contacts on the lens and adapter? Really sounds like a contact problem to me.
I feel that the construction of the MB is very precise. No issues at all. Everything fits snugly.
Could be your OOF problems are related to the other problem. I haven't had a lot of chances to try it out in the "real world", but so far, I have been quite happy with the accuracy of the AF. But I will definitely keep an eye on it.
Tord
Well-known member
The adapter and lens were purchased new. The plated contacts have no visible signs of wear so cleaning should not be a necessity. There is some play (radial, not axial), I would estimate the play about twice as much as when mounting a 4/3 lens with the genuine MMF3. It's hard to measure exactly how much, though. Maybe the electric loop between camera and lens comes open at occasion, which would explain the focus refusal. It may also be a long shot explanation why some shots become OOF, if there are some contact glitches during a sequence that would impact the control of focus motor.
Maybe the fault is in my copy the camera body? It has been in Portugal twice for repair, and according to the report it was also checked. I have never been really satistfied with the AF accurracy when using the 4/3 300/2.8 on the EM-1, and sometimes also I get OOF frames with the 50-200SWD.
I plan to do some more tests in controlled conditions, using focus charts and also 3D objects.
Question to you: What AF settings do you use? Single small AF point? Aim, acquire focus and recompose? Fire a burst or single frames and let the camera re-acquire focus for each?
@ Jules, if you read this post: You have experienced OOF too, what about focus refusal?
Maybe the fault is in my copy the camera body? It has been in Portugal twice for repair, and according to the report it was also checked. I have never been really satistfied with the AF accurracy when using the 4/3 300/2.8 on the EM-1, and sometimes also I get OOF frames with the 50-200SWD.
I plan to do some more tests in controlled conditions, using focus charts and also 3D objects.
Question to you: What AF settings do you use? Single small AF point? Aim, acquire focus and recompose? Fire a burst or single frames and let the camera re-acquire focus for each?
@ Jules, if you read this post: You have experienced OOF too, what about focus refusal?
DanC.Licks
AKA Daniel Bradley
Yes, single small, but sometimes single normal. Acquire and recompose unless there is time to move the point. Single frames. I have three "mysets", one for normal, as above, 9 points + home (single), the second with 7fps, 37 points + home , and a third with higher ISO and no IS for fast moving airborne objects. Also 7fps and 37 AF points.
At the moment all three are set to silent shutter.
I really like the silent shutter but one has to be careful. There is a lot of distortion due to rolling shutter if there is any movement. I even noticed it in taking pictures of the moon on a tripod! Fort normal use not really a problem, and I love the fact that it doesn't sound like an AK-47! I HATE being in hides with guys shooting Canons and Big Whites! They scare everything off.:C
The weather has turned warm. We had to cancel our ski week because of it, but maybe I will have some time to get out and try to get something better of these guys. Never seen them here before this year...
From a distance I thought, hey, why are there apples in that maple tree?
Also 7fps and 37 AF points.At the moment all three are set to silent shutter.
I really like the silent shutter but one has to be careful. There is a lot of distortion due to rolling shutter if there is any movement. I even noticed it in taking pictures of the moon on a tripod! Fort normal use not really a problem, and I love the fact that it doesn't sound like an AK-47! I HATE being in hides with guys shooting Canons and Big Whites! They scare everything off.:C
The weather has turned warm. We had to cancel our ski week because of it, but maybe I will have some time to get out and try to get something better of these guys. Never seen them here before this year...
From a distance I thought, hey, why are there apples in that maple tree?
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Tord
Well-known member
You shoot single frames... Could use of multiple frames explain the difference in AF accuracy? When photographing perched birds, I usually short a burst of ~3 frames in L-fps to increase chance that at least one frame will sharp, in focus, with a nice posture, open eyes etc. I think I have set the camera to 3fps.
I also have the S-AF shutter release priority set to OFF, so in theory the shutter will not release until focus is confirmed.
Still, within a sequence, camera and MB will change focus. In most cases either the first or last in the sequence has best focus. I need to check in the recycle bin if there is a clear pattern for how focus is changed over the course of a series.
When do you small/normal AF point?
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