PDA

View Full Version : FL50R - super FP mode


Tordan58
18th February 2013, 02:28 PM
Hi,

Reading through the FL50R manual I try to understand what the super FP mode exactly does. It says that it supports shooting at faster shutter speeds than the camera synch speed (1/180s). This sounds like magic.

Do you know how fast shutter times are supported?

Also, do you know if the super FP mode is supported in RC mode?

/Tord

katran
19th February 2013, 07:05 AM
Tordan,

i think there is no limit in FP mode. You can reach 1/1000 or 1/2000s.
But there is an disadvantage : flash is not very eficient in this mode.
This means the amount of light is lower than in the normal mode.
The light emited by the flash it is not continuous, it is pulsatory.

I used FL36 for BIFs in the daylight in FP mode. It did not saw any difference between using flash and no flash.
Maybe FL50R is more powerfull and makes a difference.

Tordan58
19th February 2013, 08:05 AM
Tordan, does this help ?

http://asia.olympus-global.com/imsg/webmanual/dslr_function/acc_flash/index.html

John
Hi John

Thanks for sharing a pointer to these surprisingly well written and easy to understand resources.

/Tord

Tordan58
19th February 2013, 08:25 AM
Tordan,

i think there is no limit in FP mode. You can reach 1/1000 or 1/2000s.
But there is an disadvantage : flash is not very eficient in this mode.
This means the amount of light is lower than in the normal mode.
The light emited by the flash it is not continuous, it is pulsatory.

I used FL36 for BIFs in the daylight in FP mode. It did not saw any difference between using flash and no flash.
Maybe FL50R is more powerfull and makes a difference.
Hi Katran,

At guide number 50, the FL50R is ~50% more powerful so there is some difference but not a magnitude of difference so I added a beam extender which made quite a significant difference. I haven't measured the angle of the light beam but it looks quite narrow.

/Tord

Naughty Nigel
16th October 2013, 07:42 AM
Hi,

Reading through the FL50R manual I try to understand what the super FP mode exactly does. It says that it supports shooting at faster shutter speeds than the camera synch speed (1/180s). This sounds like magic.

Do you know how fast shutter times are supported?

Also, do you know if the super FP mode is supported in RC mode?

/Tord

Super FP will work at any shutter speed up to 1/4000 second, or whatever the cameras' maximum (shortest) shutter speed is.

The whole idea of Super FP mode is that the flash lasts for the full duration of the exposure. The maximum flash synch speed using normal flash is the fastest exposure during which the shutter is fully open at some point; which is when the flash fires.

At faster exposure speeds the shutter curtains move across the sensor together with a measured gap between them. A Super FP flashgun effectively provides light throughout the exposure, whilst a normal flashgun would only expose a portion of the frame.

However, cameras with leaf shutters (like an iris) can synchronise flash at any speed, as the shutter always opens fully at any speed, and even if it didn't, the light from the flash would still reach all parts of the frame equally.

Tordan58
16th October 2013, 10:03 AM
Hi Nigel,

Thanks for input.

What I want to achive is the following.
Take pictures using long focal length (600mm, that is where the beam extender comes in), with flash support to lighten shadows (shooting against sun or against bright background e.g. sky). Simply put, us fill in flash at long range.

I tested the flash + beam extender capabilities by shooting objects in the dark and when properly aligned the flash is powerful enough for correct exposure at distances at least 25 meters at ISO 800, so the flash is not limiting me.

Now, long focal length (and also since some object not fully static) requires short shutter speed. 1/250s may be short enough, but then you run into the issue that pictures get overexposed. The aperture on my lens is fixed, so the only parameter I can play with is shutter speed/ISO and flash intensity. I would say the useful range of shutter speeds spans from 1/100 to 1/2000.

So my idea is to use TTL mode and super FP on the FL50R (to enable synch at short shutter speeds), use A or M mode on camera and adjust ISO to get a good baseline exposure time (without flash), then engage the flash to fill in. I can accept a somewhat underexposed background (as a consequence of flash intensity declining as the square of the disctance) but I don't want a black or severely underxposed background.

However I get puzzled when reading page 108 of the E5 manual :
A mode: the shutter limit can be set between 1/30 and 1/250 (*)
M mode: the shutter limit can be set between 60 and 1/250

"When the flash is set to the Super FP mode, it detects backlight and fires with a longer duration than for normal flash before emitting light."
(what this sentence exactly means is not very clear to me)
(*) Fires automatically in dark/backlit conditions

When using the super FP setting, the shortest time I can set in the camera is 1/250s which often is way too long even at ISO100

So I guess I am doing something wrong, or have totally misunderstood the user guide.

If you can bring some clarity into this it would be highly appreciated.

Ross the fiddler
16th October 2013, 12:07 PM
I'm not sure what the manual is saying there but on the E30 when using FP TTL Auto (on an FL50R) the shutter speed still goes for 1/60 in Aperture Priority & in Shutter Priority or Manual it can be any shutter speed from 60 seconds to 1/8000 sec. (& Bulb in Manual too).

FP TTL Auto is, as I understand it, ideal for fill when otherwise exposing for daylight, so that the Aperture, Shutter Speed & ISO are all selected for that daylight shot while the flash (in FP TTL Auto) can have its intensity adjusted + or - (on the flash or from the body) to suit the amount of fill needed. Using the flash extender narrows the beam for an effective longer distance, but would still have its limitations. I have used the FL50R for fill (without an extender) with some reasonable success in similar circumstances but probably not up to 25m though.

Here's a couple of examples.
http://e-group.uk.net/gallery/data/506/P1234265s.jpg (http://e-group.uk.net/gallery/showphoto.php/photo/30370)

http://e-group.uk.net/gallery/data/506/P1234254s.jpg (http://e-group.uk.net/gallery/showphoto.php/photo/30366)

Tordan58
16th October 2013, 01:57 PM
Hi Ross,

Thanks for input. The samples you have provided show an idea about what I want to achieve (although subject is underexposed, which comes probably from the range limitation using the flash without beam extender).



When you write "FP Mode" do you mean "Super FP Mode"? (I could not find any reference to "FP mode" for short).

The A mode is the one I use in vast majority of situations with a fixed aperture lens, as most people would do. S and P mode can be ruled out.

When I use A mode I am able to set the shutter speed as short as 1/250s, using the setting in the F menu --> X-Sync. That is the shortest time possible to set, which conforms to the upper limit as the user guide says (page 109).

To use even shorter shutter times e.g. 1/1000s I suppose I will need to use M mode on the camera. The workflow should, if I got it right be something like this:

Manual exposure
(in camera flash menu) Use Fill in flash
(in camera F menu) Set +/- to On (The user guide says: When set to [On], it will be added to the exposure compensation value and flash intensity control will be performed.)
(in flash) Set Super FP mode
Set ISO to suitable value depending on natural light conditions
Set shutter time to suitable value, some intentional under-exposure (since flash will fill in up to desired exposure)
Adjust flash intensity with +/- button (on camera) for desired fill in effect


Am I right in this?

photo_owl
16th October 2013, 03:25 PM
Am I right in this?

sort of

1. in M mode you don't have exposure compensation outwith the flash unit so +/- On shouldn't matter
2. even with a range extender/better beamer etc you simply aren't going to get much in the way of light at distance from FP mode - the GN starts low and falls off fast in this mode because the power needed and heat generated in the flash tube are huge. You may find this link helpful http://www.photozone.de/hi-speed-flash-sync

it's easy to test - but you have to run your tests through the range of working distances and shutter speeds; because of the way it works the shutter speed will have a huge impact on the effective range for the use you are outlining.

other things to be careful about -

1. metering - using TTL functionality you will need to ensure that the flash metering is measuring your subject matter as usual.
2. you will have slightly more power available from the flash without TTL for obvious reasons.
3. you may find auto ISO useful if you need to shoot in an unprepared way ie set camera to M, Aperture to match Lens fixed aperture, shutter to your choice and leave the camera to pick the ISO to expose correctly - add forced flash with the gun set to FP mode and you should get what you want (if it's possible from the range available).

this is a classic example of where you really want to be able to set exposure compensation with M mode - setting the above with -0.7 on camera and TTL Auto at 0.0 on the flash would give you what (I think) you are looking to achieve - but you can't. :mad: you have to have everything M, inc ISO, and meter to your desired exposure from the camera - fine for prepared shots/weak for action shooting with flash fill!

photo_owl
16th October 2013, 03:30 PM
FP TTL Auto is, as I understand it, ideal for fill when otherwise exposing for daylight, ....

nope, it's terrible relative to normal flash functionality but it's the only option if the conditions, or subject, require a faster shutter speed that the maximum sync speed available.

typically this happens in bright sunlight/daylight shooting of course, which is why the two get put together!

Naughty Nigel
16th October 2013, 03:39 PM
Hi Tordan,
There are several considerations here.

Firstly, the maximum flash synch speed on your camera is 1/250 second using a conventional flashgun. However, [from memory] the camera's menu system allows you to limit minimum and maximum automatic exposure times within the range of 1/250 to 1/30 second when using flash. This allows you to balance flash and ambient light, and also helps you to prevent camera shake by avoiding slow shutter speeds. Alternatively, you can set a slow speed if you wish to create a blurred effect, or use manual (or shutter priority exposure) to set your own shutter speed.

(If you try to make an exposure at 1/250 second in very bright conditions the shutter speed figure will flash at you to warn that you risk overexposure.)

If you use Super FP the whole game changes, as you can synchronise at any shutter speed. However, the disadvantage is that the flash duration is much longer, so the flash range is much reduced. I would therefore suggest that you use the normal TTL mode, set a shutter speed between 1/125 and 1/250 and pan your shot to keep the subject sharp whilst creating motion blur in the background.

I don't know if there are any effective range extenders for the FL50, but I know that Metz have long produced a telephoto lens for their hammerhead guns, such as the 45 CL4 series.

Finally, I don't have much experience of wildlife photography, but I have always been concerned about the effects of high powered flash on wild creatures. Are there any guidelines on this subject?

photo_owl
16th October 2013, 04:04 PM
I don't know if there are any effective range extenders for the FL50.....

From his post Tordan has one "
I tested the flash + beam extender capabilities"

as do I :)

I share your concerns re wildlife, but considering the cats, dogs, (children!) zoo animals and everyone else exposed frequently to flash on cameras, phones etc there doesn't seem to be any evidence that it causes a problem.

Personally I have stopped using any flash with new born babies as they clearly react even when asleep - so a few days without the additional exposure seems a fair trade for the next 80 years :)

Tordan58
17th October 2013, 08:27 AM
Hi Tordan,
There are several considerations here.

Firstly, the maximum flash synch speed on your camera is 1/250 second using a conventional flashgun. However, [from memory] the camera's menu system allows you to limit minimum and maximum automatic exposure times within the range of 1/250 to 1/30 second when using flash. This allows you to balance flash and ambient light, and also helps you to prevent camera shake by avoiding slow shutter speeds. Alternatively, you can set a slow speed if you wish to create a blurred effect, or use manual (or shutter priority exposure) to set your own shutter speed.

(If you try to make an exposure at 1/250 second in very bright conditions the shutter speed figure will flash at you to warn that you risk overexposure.)

If you use Super FP the whole game changes, as you can synchronise at any shutter speed. However, the disadvantage is that the flash duration is much longer, so the flash range is much reduced. I would therefore suggest that you use the normal TTL mode, set a shutter speed between 1/125 and 1/250 and pan your shot to keep the subject sharp whilst creating motion blur in the background.

I don't know if there are any effective range extenders for the FL50, but I know that Metz have long produced a telephoto lens for their hammerhead guns, such as the 45 CL4 series.

Finally, I don't have much experience of wildlife photography, but I have always been concerned about the effects of high powered flash on wild creatures. Are there any guidelines on this subject?
Hi Nigel,

Appreciate your engagement and effort supporting me, however there are a few points where I do not fully agree with you (or maybe we are misunterstanding each other)

Background: what I want to achieve is a sharp picture of a static (or semi-static) object, free of motion and shake blur, in unfavourable light angle such as against overcast sky or facing the sun. I use a long lens (600mm) with fixed aperture ~F/7. Long lens calls for short exposure time, with my setup I usually achieve good results at 1/250s but I would be hesitant to go much lower than this.

You are right in the shortest shutter time supported is 1/250s. However 1/250s is often way too long time. Most situations are shot in light conditions with Exposure Value (EV) in the range EV13 - EV15, sometimes EV12 or EV16.
With some slight underexposure of natural light and having the flash filling in the rest, 1/250 s would be useful for EV12 @ISO200 and EV13 @ISO100. But once it gets brighter than this pictures will become overexposed and the method is not useful since the ISO cannot be set to lower than 100.

Meaning I need to find a way to shoot at < 1/250s and take advantage of the "super FP mode". You write that it the flash duration is longer which puzzles me. What do you mean with "longer"? From what I have read, if I understand correcty, what the super FP mode does is to discharge the flash in a series of flashes (with very short duration, perceived by human as one flash only). The total amount of light is same as if all was emitted into one flash only, but spread over time. And that the shorter the shutter time you use, the fewer of these flashes will be captured on sensor while shutter is open, meaning the guide number will decrease in practice.

Naughty Nigel
17th October 2013, 08:40 AM
Hi Nigel,

You write that it the flash duration is longer which puzzles me. What do you mean with "longer"? From what I have read, if I understand correcty, what the super FP mode does is to discharge the flash in a series of flashes (with very short duration, perceived by human as one flash only). The total amount of light is same as if all was emitted into one flash only, but spread over time. And that the shorter the shutter time you use, the fewer of these flashes will be captured on sensor while shutter is open, meaning the guide number will decrease in practice.

Exactly. The flash duration is longer, but much of the light energy is wasted as the shutter is not fully open.

1/250 second is the fastest speed at which the shutter opens fully during an exposure (hence maximum synch speed), which means that the entire flash output reaches the camera's sensor or film. (Normal flash duration is less than one millisecond.)

At faster shutter speeds only a small proportion of the shutter is open at any one time, so the effective flash duration must be much longer to cover the entire exposure (about 40 milliseconds I think), so whilst the total flash output is the same, most of it is wasted.

Tordan58
17th October 2013, 08:57 AM
Exactly. The flash duration is longer, but much of the light energy is wasted as the shutter is not fully open.

1/250 second is the fastest speed at which the shutter opens fully during an exposure (hence maximum synch speed), which means that the entire flash output reaches the camera's sensor or film. (Normal flash duration is less than one millisecond.)

At faster shutter speeds only a small proportion of the shutter is open at any one time, so the effective flash duration must be much longer to cover the entire exposure (about 40 milliseconds I think), so whilst the total flash output is the same, most of it is wasted.
Thanks Nigel,
Do you happen to have a "formula" or guideline (or pointer to) for how the nominal guide number, 50 in the case of the FL50R, decreases with shutter speed exceeding 1/250? This would be useful and allow calculating the maximum flash range for a given shutter speed, which in turn is given by EV and controlled by ISO.

Naughty Nigel
17th October 2013, 09:04 AM
Thanks Nigel,
Do you happen to have a "formula" or guideline (or pointer to) for how the nominal guide number, 50 in the case of the FL50R, decreases with shutter speed exceeding 1/250? This would be useful and allow calculating the maximum flash range for a given shutter speed, which in turn is given by EV and controlled by ISO.

I don't have a formula, but it should be easy enough to work out.

The actual exposure time (not the effective shutter speed) will not change much above 1/250 second. All that changes is the opening between the shutter curtains which provides us with our effective shutter speed.

(An effective exposure of 1/1000 second, for example, actually takes a lot longer than 1/1000 second!)

So, if the FL50 has a guide number of 50 at 1/250 second, that will be halved at 1/500 second, and halved again at 1/1000 second, and so forth.

photo_owl
17th October 2013, 09:23 AM
Thanks Nigel,
Do you happen to have a "formula" or guideline (or pointer to) for how the nominal guide number, 50 in the case of the FL50R, decreases with shutter speed exceeding 1/250? This would be useful and allow calculating the maximum flash range for a given shutter speed, which in turn is given by EV and controlled by ISO.

there's an example in the link I provided earlier

Tordan58
17th October 2013, 09:30 AM
Thanks, I missed that one somehow. This is what I was looking for!

Tordan58
4th November 2013, 12:48 PM
After having tested various settings I recently came to insight that the super FP more is not supported in combination with RC mode... which explains why I am not able to set shutter times < 1/250s and sometimes run into overexposure. I suppose I will need a FL-CB05 cable.

photo_owl
4th November 2013, 01:34 PM
After having tested various settings I recently came to insight that the super FP more is not supported in combination with RC mode... which explains why I am not able to set shutter times < 1/250s and sometimes run into overexposure. I suppose I will need a FL-CB05 cable.


strange - it was on the E30, and I've just shot with it on the E-M1 as a test too.....

http://farm8.staticflickr.com/7301/10670860513_74a9f2d932_z.jpg

M 1/500th F6.3 ISO 320 45mm one FL50R FP TTL and one FL36R FP manual 1/10th

Tordan58
4th November 2013, 02:48 PM
When I use RC mode the range of shutter times that the camera will use is in the interval given by the settings Slow limit and X-Sync (F menu).

I discussed with Olympus support and they told me that to take advantage of TTL and super FP mode the camera and flash need to be connected (by hot shoe or cable).

Am I missing something?

photo_owl
4th November 2013, 03:03 PM
When I use RC mode the range of shutter times that the camera will use is in the interval given by the settings Slow limit and X-Sync (F menu).

I discussed with Olympus support and they told me that to take advantage of TTL and super FP mode the camera and flash need to be connected (by hot shoe or cable).

Am I missing something?

I have no idea - I can only point to the above where it was happy to shoot at 1/500th controlling 2 seperate RC flash units; one in each of the available FP modes (FP TTL auto and FP manual)

On the INFO screen RC flash set up what have you got in the top right box against the row for the A flash group? You should have this as FP...not the Flash symbol..........

http://farm4.staticflickr.com/3713/10671587474_f0dccf4ca8.jpg

Tordan58
5th November 2013, 12:36 PM
Hi

If I set the camera to RC mode I get a FP symbol in the top/right field of the A group. However, there is no way I can get shutter times shorter than the X-sync time as specified in the F menu (1/250s shortest possible) in super FP + RC mode.

If I turn RC mode off and connect the flash to the camera hot shoe then shutter times shorter than X-sync are possible to get. Also, on the flash is displayed the interval of shooting ranges, the high value follows the ISO/aperture settings with what seems a congruent relationship. I haven't tested in-depth yet, but managed to achieve what I wanted e.g. shooting at 1/1000s indoors against bright background (window) and have the flash fill in the shadows. Next I will test outddors with the Fresnel lens to determine the capability/useful range.

photo_owl
5th November 2013, 01:22 PM
Hi

If I set the camera to RC mode I get a FP symbol in the top/right field of the A group. However, there is no way I can get shutter times shorter than the X-sync time as specified in the F menu (1/250s shortest possible) in super FP + RC mode.



I can only answer for the E-M1 as I don't have any other RC capable bodies but, as I've shown, it will permit (and deliver) to any shutter speed you wish - it has 1/320 max sync but you can use 1/8000th in FP RC mode.

You need someone with the same camera body to 'double check' if that's what you are after.