Auto Shutter. . . .what is it for?

[Mark Sudfelt]

I have had a Sony PD150P for a few months now. I am using it mainly for weddings and have been relying on the auto settings for exposure for most shots except where backlighting is a problem and in the church. Had a Canon XM1 before so adjusting exposure was easier because the shutter is locked when the iris wheel is engaged(correct me if I am wrong:-) unlike the Sony where you have to lock the shutter and gain as well.

Now that I am more confident with the camera I have been concentrating on improving my use of the manual exposure controls. With that in mind I was wondering if turning off auto shutter in the menu is a good idea. I gather that the shutter is then locked at 1/50 although the PD150 manual makes no reference to this. I thought that by turning the shutter off it would be one less thing I would have to worry about when going to manual exposure during the heat of a wedding shoot. I would have to make sure I engaged the correct ND filter when prompted but are there any downsides to locking the shutter.
And if so, why is the option there in the menu?

Regards,
Mark Sudfelt.

[John Jay]

hey

you dont have to worry about auto shutter in manual mode.

you can dial up any speed you like, then adjust your iris to the light gain or loss

[Mike Rehmus]

If by lock, you mean place the shutter speed into manual mode, then the advantage is that if you do not, the camera will not truly be in manual mode.

With the PD150 you must have shutter speed, gain, and aperature in manual mode or the camera will make its own exposure determination and modify any of the settings that are left in automatic mode.

Some people think this is a mistake but truly it could be no other way. It allows one to modify one parameter but have the camera set exposure by countering with another parameter. So one can fool with depth of field using the aperature control without also having to worry about adjusting one of the other 2 parameters so as to maintain a correct exposure.

So you can have one or 2 parameters in manual mode and still get automatic exposure control or you can place all three in manual mode and run exposure yourself.

[Andre De Clercq]

Mark, if you turn off the auto shtr in the menu there is a risk that in very bright situations the aperture starts to close down (a lot futher than f-11) resulting in resolution reduction by diffraction because the shutter time reduction/compensation can no longer occur. So it is not advisable unless you specifically need that paricular shutter setting at the expense of potential resolution reduction.

[Wayne Orr]

Confused enough yet, Mark? Let's see what I can do to add to the confusion. When you look in the viewfinder or lcd, you see various items listed. Here is the rule: If you don't see an item listed, then it is in automatic. "But I turned off automatic shutter in the menus," he protested. No matter. If you don't see the shutter speed indicated in the display, it's not locked. What this means in the real world is, you may be shooting in a low light situation, with the iris wide open, and unbeknownset to you, the shutter has gone to a slower speed to make up for the lack of light. Actually, you would know if you were paying attention, because the picture would start with that slow shutter stutter. Did I really say that? Anyhow. You must see the item in the viewfinder/lcd to be certain it is locked, or as Sony says, in "hold." Maddening.

The "big three" items you are interested in are "gain," "iris," and "shutter speed." You will always want to check these with the slider in the center, or "hold" position. If you don't see one of these listed, it is in auto. Hate to keep repeating this, but it is very important. If you want to leave the iris in "auto" mode, fine as long as you see the other two indicated.

Turning "off" auto shutter in the menus means that if you are shooting in "full auto" mode, the camera will not change the shutter setting, since this is where the most dramatic change in picture quality can occur, as I alluded to above. But if you are shooting in the "hold" position, and you do not see the shutter setting, the camera may change the shutter setting.

Why would you ever use the lower position on the slider, what Sony calls "locked?" So you can avoid making a mistake like I did one time where I wanted to adjust an audio setting, and started spinning the wheel. Unfortunately I was on "white balance" and unkowingly moved the setting from "bulb" to "daylight" and didn't discover the mistake because I was looking at the wonderful black and white finder.

HTH

[Andre De Clercq]

Wayne, when the auto shtr is "off" in the menu settings the shutter speed remains locked, whether it is prompted or not in the viewfinder. I just reverified this on a VX2000.

[Wayne Orr]

<<<-- Originally posted by Andre De Clercq : Wayne, when the auto shtr is "off" in the menu settings the shutter speed remains locked, whether it is prompted or not in the viewfinder. I just reverified this on a VX2000. -->>>

Thanks for taking the time to test it out, Andre. However, here are a couple of links that disagree with your results.

http://www.ieba.com/research/DSR250problems.html
> ISSUE 2: Automatic Shutter menu actually has no effect- it can't be disabled. (also affects PD-150)
> Set everything to manual (three sliding switches next to your right cheek) so you are not on full auto, not on ATW, not on auto gain. Go into the menu to turn off the last auto... auto shutter. Now use your ring finger to turn the iris to manual just like you would with ANY other professional camcorder- which what the DSR-250 is. Adjust your iris for a dark situation. Swing the camera to something bright the image should wash out... right? Wrong!!!
> The camera still takes over the shutter and closes down (increases the shutter speed) for proper exposure. The little "shutter" light in the viewfinder even comes on! The only way I can find to disable this is to turn the manual shutter switch under the lens on... and set it to 60 (or any set number) which is what the camera ought to be doing by default.
> Sony POSC confirms what I found- the DSR-250's Automatic Shutter menu setting does absolutely nothing.
> In order to get the camera to really be what any professional user would call "manual," you have to turn the shutter on under the lens, and leave it on, all the time (!) so that when you put the iris in manual, the shutter doesn't kick in and "correct" your exposure for you. This is completely opposite from every professional camcorder where you can set the manual shutter speed to anything you choose, 1/500, 1/67.2 (clearscan) or 1/15 (slow shutter effect) and enable that manual shutter setting, and disable it with the flick of a switch. Not with the DSR-250! You must now use the manual shutter to force the camcorder to shoot at 1/60 (1/50 PAL) second and then go through the menus every time you need a different shutter speed.
> This issue also affects the PD-150. I have also had one report that PAL camcorders are affected by this programming bug. Independent tests confirm that disabling the automatic shutter does absolutely nothing. This is not like the programming on the VX-1000, or the TRV-900. Other people have tested those camcorders and confirmed that you do NOT have to enter a manual shutter speed in order for the camcorder to stay at 1/60 (1/50 for PAL) This indicates that new programming was introduced with this camcorder, and it was programmed incorrectly.
> Sony needs to correct the programming so that disabling the automatic shutter in the menu does what it is supposed to do and the DSR-250 works like the pro camcorder it is supposed to be. This is a problem which needs to be fixed.

(Actually, I don't agree with the author's conclusion. I think the camera operates differently from what he was used to, and he sees this as a design error.)

Here is another link from this obscure website:
http://www.dvinfo.net/sony/tips.php

And the beat goes on. A very confusing subject, Andre, and I have no answer to your experiment. But I would tell newbies, "If you don't see it indicated in the viewfinder/lcd, it is not locked."

[Andre De Clercq]

The whole confusion I think, relates to the fact that for "normal use" of the camcorder it will do nothing. If one "forgets" however to apply the ND filters or the amount of light entering the lens goes beyond the limits set by f11 and the ND2 then the auto shutter acts (if it is "on"). When it is "off" the aperture start to go byond F11 introducing the known diffraction effects.

[Rick Spilman]

When I have time I am going to sit down and read this thread very carefully. I used to think I understood the auto shutter setting. Now I will admit I am confused.

Rick

[Mike Rehmus]

Hmmm.

When my PD150 is in full manual mode, nothing I can do to the camera changes the shutter speed except pressing the shutter speed button and then operating the thumbwheel.

If I place the camera in hold, the translucent bar 'under' the camera speed readout goes away but the shutter speed stays on screen. It is indeed locked. Nothing I can do will change that value.

This new camera works just like my old camera did in this respect.

Am I missing something about setup that would cause this not to work as I described?

[Wayne Orr]

OK. I did some tests with my PD150 and discovered the following: with the camera in Full Auto mode (with the slider all the way up) I pointed the camera at a bright light and ignored the request to insert the ND2. I shot a bit of footage, and then played it back with the data information switched on to see what the camera selected. It indicated the iris was at f/11 and the shutter speed was 250. Next, I went into the menu and found "Auto Shutter," which I switched to "Off." I re-shot the demo and played it back. This time the iris indicated f/11, but the shutter speed was only 60 which would be "normal" for an NTSC camera.

I then repeated the experiment in the "Hold" position (the middle position of the silver slider). I set the exposure to 2.4 and shot the light with the gain locked, but not the shutter speed. In other words, I could see the 2.4 and the 0 gain in the lcd, but no shutter speed. (Remember, the "Auto Shutter" is still set to "Off.") I then shot the scene and played it back. The data information indicated the iris at 2.4, but the shutter speed was 2000! Obviously, the shutter speed was not locked. Now I set up the shot again, this time with the iris of 2.4 and a shutter speed of 60, as indicated in the lcd. I shot some footage, and when I played it back, the data indicated the shutter held at 60, along with the iris at 2.4. I believe this confirms the proposition that if it is not indicated in the lcd/viewfinder, it is not locked. However...

I also did the experiment in low light conditions, expecting that with the iris locked at 2.4 and the gain locked at 0db, but leaving the shutter speed available to the camera, that the camera would add a slower shutter speed to compensate for the lack of light. It did not do this, however, and when I played back the data, it indicated a shutter speed of 60. It made no difference whether the "Auto Shutter" was in "On" or "Off."

My conclusion is that the "Auto Shutter" switch refers to the camera in "Full Auto" mode. It will have no effect when shooting In the "Hold" mode. For most shooters, it is probably adviseable to leave the "Auto Shutter" in the "Off" position to avoid the possibility of the unusal movement signature of high speed shutters. And again, when shooting in "Manual" or "Hold" mode, if you don't see the iris setting, gain and shutter speed in the lcd, you are not truly in Manual mode.

This has been confirmed with my PD150, and I believe it would be correct for the VX2K also.

I welcome your comments.

[Andre De Clercq]

The shutter adaption (if auto shtr is "on") only compensates for overexposure. Again, if it is "off" the overexposure is being compensated by smaller apertures (>f11, not indicated in by the data code). Like I already mentioned, I would prefer to keep it "on" because the loss of resolution is very significant.(tested!) I would prefer sharpness above potential strobing if there is fast motion in the picture. On both setting it garantees "full auto" (excuding shutter values below full system setting 1/50-1/60) and this is the basic phylosophy why the (non promted!) exposure correction exists.

[Wayne Orr]

I agree with what you are saying, Andre, up to your last statement, which I find confusing; "On both setting it garantees "full auto" (excuding shutter values below full system setting 1/50-1/60) and this is the basic phylosophy why the (non promted!) exposure correction exists." If you could explain in a bit more detail.

My point, which my tests demonstrate, is that, if you think putting your "Auto Shutter" switch to "Off," will lock your shutter speed when you are in "Hold" mode, you are mistaken. You must see the shutter speed indicated in the finder to be certain it is indeed locked. I think this will explain why some people have had a "problem" with their camera. They think they are in full manual mode and when they pan from a dark area to a brighter area they see the brightness level adjust to the new lighting condition. They erroneously may think this is the iris adjusting, but in fact it is the shutter speed adjusting to the brighter condition. "But I set the "Auto Shutter" to 'off'" they protest. But that only controls the shutter speed in full auto. You must set the shutter speed and see it in the viewfinder/lcd to lock in the setting.

Sorry if this is going on a bit long, but this is a very important concept to understand, because when it happens to you, it can make you crazy.

[Andre De Clercq]

The "hold" mode holds whatever has been set manually, and no (accidental) changes can be made. It does not at all relate to "full manual mode". If AE-S (shutter priority) has been chosen and you go with this setting in the "lock" mode the cam will still behave (and be blocked) in the AE-S mode. This means, depending on the light conditions, the iris will react, keeping the shutter speed fixed. If the amount of light becomes too high (and only then), depending on the auto shtr setting in the menu the shutter will start to change(auto shtr "on") or the iris will l further close down (auto shtr "off") and exceed F11. B.t.w. if you want to "see" the shutter speed reactions try to put a crt monitor screen image visible while you do you shooting experiments. The width changes of the horizontal band tells you everything about the shutter behaviour.

[Wayne Orr]

I think I have to apologize to the poster in Belgium for my English. In my above posts I used the word "hold" to refer to the manual adjustment position (center position on the slider). This is incorrect when you use the Sony manual (English) which, on page 42 identifys the three positions on the selector, from top to bottom, as: Auto lock, Manual position (Auto Lock release), and Hold. Why they didn't simply list the three as Auto, Manual, and Lock is subject for another post dealing with semantics and translation. Anyway, I also apologize to any readers who were confused by my mis-labeling of the functions.

I have a couple questions for Andre regarding today's post. How exactly do you chose "AE-S" which I assume means "Auto Exposure-shutter priority?"

"This means, depending on the light conditions, the iris will react, keeping the shutter speed fixed. If the amount of light becomes too high (and only then), depending on the auto shtr setting in the menu the shutter will start to change(auto shtr "on") or the iris will l further close down (auto shtr "off") and exceed F11." This is correct, but only in the "Auto Lock" mode. In the "Auto Lock realease" mode (aka Manual) the "Auto Shutter" setting in the menu has no effect. The shutter will be "held" only if you see the setting indicated in the finder/lcd. I refer to the note on the bottom of page 43.
"The functions (iris, gain, and shutter speed) that are not adjusted manually will be automatically adjusted according to shooting conditions." In other words, if you don't see a function listed in the finder/lcd, it is not locked and is in auto mode. No mention is made of an exception if the "Auto Shutter" is switched to "Off," since the Auto Shutter only refers to when the camera is in Auto Lock mode.

In regards to the "Hold" mode, or what I prefer to call "Locked," the same holds true. If the shutter speed is NOT indicated, and with the "Auto Shutter" set to "Off," the camera will still adjust the shutter in the "Hold" mode. I guess this could be called a "shutter priority" setting? I have very little experience using the "Hold" setting since I usually want to be able to adjust the iris, but I can see where this might be valuable in certain conditions. I certainly wish I had used the "Hold" setting when we shot our Motor City Madness show to keep me from changing the white balance setting accidentally.