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EFCS & Flash in LV Circuit
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mjkzz



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PostPosted: Sat Feb 24, 2018 7:19 pm    Post subject: Reply with quote

FWIW, here is a video on how to program 8-Pin AVR using Arduino

https://www.youtube.com/watch?v=30rPt802n1k
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mawyatt



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PostPosted: Sat Feb 24, 2018 7:25 pm    Post subject: Reply with quote

Peter,

Sure a micro can do this, it's trivial. But I don't have an Arduino, nor have I used a 1$ MCU. So rather than get these items and learn to program again, I took the easy way out with a couple 555 timers Very Happy

Long ago when the Apple II first came out I designed a digital voltmeter, oscilloscope and spectrum analyzer for the Apple II. I did all the hardware and software design myself. It was a plug in card that fit into the Apple bus. I wrote the 6502 machine code in time dependent format, and wrote the computations and display in complied Applesoft. After that project I told myself I would never program again!!

Later I got roped into developing a program to compute the Inverse LaPlace Transform of arbitrary functions utilizing a technique involving the Central Limit Theorem I recall, after that I told myself for sure I'm not programming again!!

Did some tweaking of code some years later, but have stayed away from programming since Rolling Eyes

Just saw the link, thanks. That looks interesting Smile

Best,
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mjkzz



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PostPosted: Sun Feb 25, 2018 4:16 am    Post subject: Reply with quote

Mike,

When trying to get an 8-Pin AVR, I happened upon a device called DigiSpark, I do not know why I forgot this Kickstarter project. Anyways, it is a complete self contained Arduino (with less pins, of course). I searched on eBay, it costs about 2USD. Basically, the guys who made it happen wrote a bootloader so that you do not need a programmer, you program it via USB (serial), and you can use Arduino (free) development environment.

I hope this little device will NOT make you say"I will not program again"

Very Happy I believe you will enjoy it, it is a lot of fun.

Anyways, I will write a blog about it and since it has 6 pins, I will probably add some high powered MOSFET so we can control some LEDs, too.
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billjanes1



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PostPosted: Sun Feb 25, 2018 5:42 am    Post subject: Reply with quote

mawyatt wrote:
rjlittlefield wrote:
mawyatt wrote:
Think I know why Nikon doesn't allow flash while in EFCS mode in Live View, or at least a reason to be cautious when using such. Since EFCS has no conventional shutters...

I'm confused. My understanding is that EFCS = Electronic First Curtain Shutter, with the second curtain being mechanical as always. Does your D850 not end exposure with a mechanical shutter?

--Rik


Rik,

I think that is how it works in Live View, but not absolutely sure. When using the View Finder I believe the mechanical rear curtain is used to terminate the exposure, but not in Live View....it's terminated electronically and thus possible to penetrate the electronic shutter while in read out phase.


Mike and Rik,

I think there is some confusion regarding EFCS and silent live view photography on the D850. For EFCS the release mode must be Q, Qc, or Mup as set on the dial on the top of the camera just to the left of the view finder. EFCS is enabled or disabled with custom setting d6. With other release modes, the mechanical shutter is used regardless of the option selected.

Shutter delay (custom setting a5) can be used with the Q release mode and EFCS. You can see what is going on with the mirror and the shutter by taking the lens off the camera and using a shutter speed of 3s and a delay of 3s. With these settings, pressing the shutter causes the mirror to be lifted and the first curtain opened immediately and you can see the sensor. The exposure via EFCS is made after the 3s delay and the second curtain comes down. The entire process takes 6 seconds. The mirror is not lowered until the shutter button is released. With EFCS off, the first curtain is not raised immediately on shutter press, and the exposure is made after the 3 second delay. Live view is not necessary here.

Without the shutter delay, the mirror is raised and the EFCS exposure is taken immediately, and shutter vibrations may degrade the picture. On my camera, I leave EFCS on at all times, but it is not used with the normal release mode S.

Silent live view photography is invoked from the photo shooting menu (camera icon on the left of the LCD). Of course, the camera has to be in live view. One can use SL1 (mode 1) for normal photography with the image area, size, and quality values selected in the shooting menu or SL2 for reduced resolution and a faster frame rate. Silent live view can be used with the normal S release mode, and EFCS is not used in this mode as per the manual.

Silent photography can also be used with focus shift shooting via an option in the focus shift menu. With this option, the shots are taken in complete silence, indicating the mechanical shutter is not in use. It is not necessary to use live view in this case.

This is my understanding of the situation, and further discussion is welcome.

Bill
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mawyatt



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PostPosted: Sun Feb 25, 2018 8:01 am    Post subject: Reply with quote

Quote:
Mike and Rik,

I think there is some confusion regarding EFCS and silent live view photography on the D850. For EFCS the release mode must be Q, Qc, or Mup as set on the dial on the top of the camera just to the left of the view finder. EFCS is enabled or disabled with custom setting d6. With other release modes, the mechanical shutter is used regardless of the option selected.

Bill,

Don't think there is any confusion with my D850. I use Live View and EFCS with Single "S" Mode (or "Q" or "Qc"). I hear absolutely no sound from the shutter nor mirror, none. I placed my ear right next to the camera and hear nothing. OK, I may be somewhat deaf, but in Live View hear no sound. Outside Live View yes the shutter is audible, as is the mirror. I think the D850 is different than the D810 in the way EFCS works, but I have no D810 to evaluate so can't say for sure. When I get some time I may check the D500, but other priorities at the moment, like replace the baseboards in one of the bedrooms Confused



Quote:
Shutter delay (custom setting a5) can be used with the Q release mode and EFCS. You can see what is going on with the mirror and the shutter by taking the lens off the camera and using a shutter speed of 3s and a delay of 3s. With these settings, pressing the shutter causes the mirror to be lifted and the first curtain opened immediately and you can see the sensor. The exposure via EFCS is made after the 3s delay and the second curtain comes down. The entire process takes 6 seconds. The mirror is not lowered until the shutter button is released. With EFCS off, the first curtain is not raised immediately on shutter press, and the exposure is made after the 3 second delay. Live view is not necessary here.


I've been using the Mirror Up with an Exposure Delay of 3 seconds and an exposure of 2~3 seconds using Rear Curtain Hot Shoe Flash Trigger with my D800 and D800E since I got the D800 when they came out. Agree, this is a very good method. Having the focus rail still moving while the Mirror is flipping up may save some time. This allows both the vibrations due to the rail movement and the Mirror to subside together and saves a second or so. Good way to operate if you don't have EFCS, and need to use Hot Shoe Flash triggering.

The D850 is certainly a complex camera with lots of features and nuances to learn, a masterpiece of camera engineering, and a nightmare to learn Rolling Eyes

The EFCS was a priority for my use, as the 46MP and Dynamic Range. Now the AF capability (D5 Pro Sports system) has come into play, even though not on my initial list, as my granddaughters are high level performers in gymnastics and snow boarding (they don't live in Florida where I live but in Flagstaff Az). On my recent return from a IEEE conference out west I stoped by for a visit and attended a gymnastics meet at Northern Az University. I used my daughter's D5100 to get some action shots, and got a few good ones but the AF system became a hindrance (hit & miss). So next meet I'll take the D850 with it's superb AF system.

Anyway, the EFCS shutter behavior under Live View seems to confirm what I've seen with the electronic shutter "bleed thru" (ghosting) with high intensity strobe/flash and why Nikon may have decided to defeat Hot Shoe Flash Triggering during EFCS and Live View use.

Best,
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mawyatt



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PostPosted: Sun Feb 25, 2018 9:04 am    Post subject: Reply with quote

Bill,

Many times I find the Japanese & Chinese manuals difficult to interpret (Yonguno is one of the worst), and Nikon is certainly not the best I've seen as with my prior cameras. So I generally do trial and error testing to find out how stuff works after reading the manual multiple times, then go back and reread, then trial & error test some more and so on. Sometimes I'll read on-line reviews, like Steve Perry or Nasim Mansurov, which seem to "get it" right and can convey such. Eventually I hope to hone in on how the camera works, and get an intuitive understating of such. The problem is I forget stuff faster than I can remember it, so I'm fighting a losing battle Crying or Very sad

Since you have the D850, can you put it in Live View with EFCS and see (listen) what happens with the electronic shutter Smile

Maybe Robert can try this as well, he has a D850 also Wink

Best,
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mawyatt



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PostPosted: Sun Feb 25, 2018 3:52 pm    Post subject: Reply with quote

Bill, Rik,

Finished most of my chores around the house, still have a few more but I'll get to them later.

I just took my D500 and ran a quick test in Live View with EFCS active. It's not in my setup and I have a standard lens on it (Tamron 24-70). I can hear the shutter loud and clear on any of the "S", "Q", "Qc" & MUP settings. Ran the test in AP and Manual modes. Removed the Tamron and attached an empty extension tube set. Ran the same test (obviously manual mode).

The results were in every case I could hear and feel the mechanical shutter even though I was in Live View and EFCS, the Q and Qc modes were slightly more quite as expected, but the mechanical shutter was still utilized.

As I mentioned before the D850 has none of this behavior, it is absolutely quite without any apparent mechanical shutter in Live View with EFCS.

So apparently the D850 is unique within the Nikon family (think the D810 is similar to D500) in this respect.

Rik, this is an important subject IMO, should we start another thread?

Best,

Mike
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billjanes1



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PostPosted: Sun Feb 25, 2018 5:03 pm    Post subject: Reply with quote

mawyatt wrote:
rjlittlefield wrote:
mawyatt wrote:
Think I know why Nikon doesn't allow flash while in EFCS mode in Live View, or at least a reason to be cautious when using such. Since EFCS has no conventional shutters...

I'm confused. My understanding is that EFCS = Electronic First Curtain Shutter, with the second curtain being mechanical as always. Does your D850 not end exposure with a mechanical shutter?

--Rik


Rik,

I think that is how it works in Live View, but not absolutely sure. When using the View Finder I believe the mechanical rear curtain is used to terminate the exposure, but not in Live View....it's terminated electronically and thus possible to penetrate the electronic shutter while in read out phase.


Mike and Rik,

I repeated my tests with the D850. I put the camera in S release mode. EFCS was enabled and Silent Live View Photography was disabled. I took the lens off the camera and set the shutter speed to 3s in manual mode. On pressing the shutter button the first curtain closed momentarily and then re-opened, and after 3 s the rear curtain terminated the exposure and then reopened to reinstate live view. Thus is consistent with your Rik's impression that EFCS must be terminated by the rear curtain.

With silent live view enabled in the SL1 mode and with the camera in live view, there was no shutter action and the sensor was visible at all times, consistent with Mike's observations.

Regards,

Bill
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billjanes1



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PostPosted: Sun Feb 25, 2018 5:12 pm    Post subject: Reply with quote

mawyatt wrote:
Bill,

Many times I find the Japanese & Chinese manuals difficult to interpret (Yonguno is one of the worst), and Nikon is certainly not the best I've seen as with my prior cameras. So I generally do trial and error testing to find out how stuff works after reading the manual multiple times, then go back and reread, then trial & error test some more and so on. Sometimes I'll read on-line reviews, like Steve Perry or Nasim Mansurov, which seem to "get it" right and can convey such. Eventually I hope to hone in on how the camera works, and get an intuitive understating of such. The problem is I forget stuff faster than I can remember it, so I'm fighting a losing battle Crying or Very sad

Since you have the D850, can you put it in Live View with EFCS and see (listen) what happens with the electronic shutter Smile

Maybe Robert can try this as well, he has a D850 also Wink

Best,


Mike,

I agree that the manual is poorly written, which is nothing new for Nikon. At least they use proper English grammar and syntax, which is an improvement over when I first used Nikon nearly 50 years ago.

I also forget what I have learned, especially if I am not using the camera features often. At least, it is easier to learn the second time around Smile. My learning experience is similar to yours-- a lot of trial and error and reading of good reviews.

Regards,

Bill
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mawyatt



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PostPosted: Sun Feb 25, 2018 6:56 pm    Post subject: Reply with quote

billjanes1 wrote:
mawyatt wrote:
rjlittlefield wrote:
mawyatt wrote:
Think I know why Nikon doesn't allow flash while in EFCS mode in Live View, or at least a reason to be cautious when using such. Since EFCS has no conventional shutters...

I'm confused. My understanding is that EFCS = Electronic First Curtain Shutter, with the second curtain being mechanical as always. Does your D850 not end exposure with a mechanical shutter?

--Rik


Rik,

I think that is how it works in Live View, but not absolutely sure. When using the View Finder I believe the mechanical rear curtain is used to terminate the exposure, but not in Live View....it's terminated electronically and thus possible to penetrate the electronic shutter while in read out phase.


Mike and Rik,

I repeated my tests with the D850. I put the camera in S release mode. EFCS was enabled and Silent Live View Photography was disabled. I took the lens off the camera and set the shutter speed to 3s in manual mode. On pressing the shutter button the first curtain closed momentarily and then re-opened, and after 3 s the rear curtain terminated the exposure and then reopened to reinstate live view. Thus is consistent with your Rik's impression that EFCS must be terminated by the rear curtain.

With silent live view enabled in the SL1 mode and with the camera in live view, there was no shutter action and the sensor was visible at all times, consistent with Mike's observations.

Regards,

Bill


Bill,

Thanks for running the test. This (no mechanical action at all in LV) is unique I think with Nikon, the camera is totally quite.

Awhile back I got some LEDs bulbs in a "Corn" style to fit in my studio strobes and replace the hot modeling incandescent bulbs. I ran a long stacking session at high magnification (setup already in place with D850 and Mitty 20X) to see how well the LEDs would work for continuous illumination (they worked very well). For a proper exposure required about a 2 second exposure I recall. I did the test with the D850 in EFCS and LV and couldn't hear anything put the strobe fans. I could barely make out the very quite THK KR20 focus rail I was using when it moved, but it was only making 2.5 micron steps. Was kind of nice without strobes flashing and no camera shutter sounds.

Best,
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rjlittlefield
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PostPosted: Sun Feb 25, 2018 9:07 pm    Post subject: Reply with quote

billjanes1 wrote:
With silent live view enabled in the SL1 mode and with the camera in live view, there was no shutter action and the sensor was visible at all times, consistent with Mike's observations.

The ability to run in this mode -- full resolution with entirely electronic shutter -- is new information to me. I find it very encouraging!

Quote:
Rik, this is an important subject IMO, should we start another thread?

That sounds like a good idea. My current guess is that we still have little enough overlap that I can split the current thread to make the new one. But that operation cannot be un-done, so I need to read carefully and make sure it won't mess up the flow too badly. Stay tuned...

--Rik
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mawyatt



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PostPosted: Tue Feb 27, 2018 2:43 pm    Post subject: Reply with quote

mawyatt wrote:
Finally got back in town and had enough time to put this together on a plug in breadboard, parts came in too.

Good news is it works as expected, bad news is I won't be able to properly solder this on a board as a loss in the family will consume my time for next few weeks.

Here's the schematic, only significant change is the input is capacitive coupled rather than direct (was having some sensitivity issues with direct couple scheme). The tolerance on the components isn't critical as indicated.

I've tested this with a Nikon D850 and Adorama DG600 strobe & 300 Studio Strobe utilizing direct wired triggered, Adorama R2 RF remote triggered and an old Neewer RF (433MHz) RF trigger.

After initially setting the delay pot near the required resistance (~120K) for the delay for the D850 (145ms). The D850 was set to EFCS mode and triggered from a Stackshot controller in Live View, the shutter speed was initially set to 1 second. The delay was adjusted until the image was fully captured, then the shutter was reduced to 1/5 and the delay adjusted until the image was captured without any shadows, then 1/10 and 1/20 and repeated. I found the D850 will have some variation in it's delay response in Live View, especially if an external monitor is used. Since any delay variation in the camera will show up in the moment the image is captured, this could cause a shift between the effective shutter opening and the strobe firing, since these are no longer synched by the camera. This isn't a problem normally because the camera initiates the strobe trigger signal from the hot shoe, thus any delay variation in the camera from an external trigger doesn't effect the trigger of the hot shoe signal relative to the shutter, however we are going around this because Nikon doesn't allow the camera hot shoe trigger in EFCS. Because of this variation in delay I've used a shutter of 1/10 to allow for this in camera shutter delay variation. I might tighten this up later but at 1/10 I see no exposure from ambient light, so the image is being only exposed by the strobe, and I see no shadow effects from the shutter.

Under these conditions the delay trigger system works whether directly attached to the strobes, or by Neewer or Adorama RF triggers. No changes in the delay setting was required when switching between the direct and RF triggers.

Here's the schematic used, and the wired plug board.



Note, D1 are optional LEDs and Trigger Input is on schematic left and Delay Trigger Out is on right.

Quote:
See the first post for details if you want to build this Delay Trigger Circuit. I'll reserve a few core parts for contributing members that are skilled in scratch electronics assembly & test. Please PM me and send a prepaid and pre-addressed self return cushioned envelope.


Think I know why Nikon doesn't allow flash while in EFCS mode in Live View, or at least a reason to be cautious when using such. Since EFCS has no conventional shutters, the possibility of intense short duration light (like from a strobe or speed-light), occurring after the shutter period causing an image problem is high. Without a mechanical shutter in Live View the sensor is optically exposed after the shutter period during readout, no mechanical shutter nor mirror to block the optical path. The optical light burst could contaminate the pixels before or during the readout phase and corrupt the final image after the shutter period. I've seen evidence of this with partially exposed subjects appearing in the image after the electronic shutter has "supposedly closed" but the optical flash duration extends beyond the specified shutter period outside the exposure period window. It looks like a dark band as expected except some of the subject is shown thru the dark horizontal bands, looking like a bleed-thru effect.

Best,


Quote:
See the first post for details if you want to build this Delay Trigger Circuit. I'll reserve a few core parts for contributing members that are skilled in scratch electronics assembly & test. Please PM me and send a prepaid and pre-addressed self return cushioned envelope.



I'll be making a few of these parts sets available for a short time.

Best,

Mike
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rjlittlefield
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PostPosted: Tue Feb 27, 2018 3:07 pm    Post subject: Reply with quote

rjlittlefield wrote:
billjanes1 wrote:
Rik, this is an important subject IMO, should we start another thread?

That sounds like a good idea. My current guess is that we still have little enough overlap that I can split the current thread to make the new one. But that operation cannot be un-done, so I need to read carefully and make sure it won't mess up the flow too badly. Stay tuned...

--Rik

I decided the guess was wrong: the various posts look too intertwined to do a clean split. So I'm leaving things as they were.

If we want to discuss D850 fully electronic shutter further, then lets start a new thread to do that, with cross-reference back to this one as needed.

--Rik
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mawyatt



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PostPosted: Tue Feb 27, 2018 3:13 pm    Post subject: Reply with quote

rjlittlefield wrote:
rjlittlefield wrote:
billjanes1 wrote:
Rik, this is an important subject IMO, should we start another thread?

That sounds like a good idea. My current guess is that we still have little enough overlap that I can split the current thread to make the new one. But that operation cannot be un-done, so I need to read carefully and make sure it won't mess up the flow too badly. Stay tuned...

--Rik

I decided the guess was wrong: the various posts look too intertwined to do a clean split. So I'm leaving things as they were.

If we want to discuss D850 fully electronic shutter further, then lets start a new thread to do that, with cross-reference back to this one as needed.


--Rik


Ok, if you, Bill or others want to start the D850 thread I'll participate.

Best,
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mawyatt



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PostPosted: Sat Mar 17, 2018 5:35 pm    Post subject: Reply with quote

Final got some time and been in town long enough to build the circuit this afternoon on a proper circuit board.

Haven't done any stacking with it yet, but did check it out. Works as expected.

Best,


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