auto flash mode use with ND filter set up? also use with leaf shutters...

Aaron28 · 01-09-2020, 05:07 PM

reckon I could experiment but why not ask...…

the af360 or 540 offer auto mode (NOT p-ttl) which iso & fstop can be set and the flash itself determines the exposure.....I like using the mode especially with non'A' lenses and usually get nice results

the question (or experiment) to see if the 'theory' is on track is if I get 2 stops from ND filter use from 1/500 down to 1/125(under sync/sync) with 200iso at f2.8

do I input f5.6 at 200iso on the flash to compensate for the 2 stop loss?

the idea is to gain confidence in results digitally then translate to film use

secondly is it true that sync speed is not necessary when using a leaf shutter (whether rangefinder or TLR) and flash??
have read more than once on various camera reviews that flash could be used at any speed when a leaf shutter is being used

thanks

Aaron

Last edited by Aaron28; 01-09-2020 at 05:30 PM.

photoptimist · 01-09-2020, 05:21 PM

If the Auto mode is P-TTL (using a preflash to measure how the flash lights the scene), the it will work fine with ND filters.

Theoretically, leaf shutters can sync at all speeds. In practice, the time it takes to open the leaf shutter for the fastest shutter times means that the aperture might not be fully opened during the entire flash burst. The result wil be a slight dimming of the flash illumination and a subtle reduction or feathering of any bokeh created by the flash.

Aaron28 · 01-09-2020, 09:41 PM

Originally posted by photoptimist

If the Auto mode is P-TTL (using a preflash to measure how the flash lights the scene), the it will work fine with ND filters.

no pttl....auto mode setting the iso and fstop which is available on the 360 & 540 and various other flashes that have their own sensor

Originally posted by photoptimist

Theoretically, leaf shutters can sync at all speeds. In practice, the time it takes to open the leaf shutter for the fastest shutter times means that the aperture might not be fully opened during the entire flash burst. The result wil be a slight dimming of the flash illumination and a subtle reduction or feathering of any bokeh created by the flash.

thanks that kinda backs up and gives more depth to what I have read......reckon it will be experimenting.....again in this scenario was hoping to use the auto mode (setting iso & fstop) on the flash

stevebrot · 01-09-2020, 09:45 PM

Originally posted by Aaron28

the af360 or 540 offer auto mode (NOT p-ttl) which iso & fstop can be set and the flash itself determines the exposure

Originally posted by Aaron28

the question (or experiment) to see if the 'theory' is on track is if I get 2 stops from ND filter use from 1/500 down to 1/125(under sync/sync) with 200iso at f2.8

do I input f5.6 at 200iso on the flash to compensate for the 2 stop loss?

That is what I would do and what works when using B&W filters for film.

Of course, the easiest way to see is to simply do it as a test. Assuming you have an "auto" flash, give it a try.

Originally posted by Aaron28

secondly is it true that sync speed is not necessary when using a leaf shutter (whether rangefinder or TLR) and flash??

It is true that a leaf shutter is not bound by a maximum shutter speed as long as the flash duration is shorter than the shutter duration.

Steve

stevebrot · 01-09-2020, 09:48 PM

Originally posted by stevebrot

It is true that a leaf shutter is not bound by a maximum shutter speed as long as the flash duration is shorter than the shutter duration.

Note that using the "Auto" flash mode manages exposure by varying the duration of the flash.

Steve

Aaron28 · 01-09-2020, 10:13 PM

Originally posted by stevebrot

Note that using the "Auto" flash mode manages exposure by varying the duration of the flash.

yes that is my understanding as the sensor on the flash turns it off when it reaches it's goal.....i.e. 100iso @ f2.8 or whatever its set at and receives such reflection back to turn off

Originally posted by stevebrot

Assuming you have an "auto" flash, give it a try

yes af360fgz & af540fgz have these modes.....use them often at sync speed with no ND or any filter with nice results......just curious about the manual compensation to adjust for having a ND filter on the lens.......going to experiment but wondering if i am taking the right approach to get started

Originally posted by stevebrot

That is what I would do and what works when using B&W filters for film.

leads me to believe i might be on the right approach to get started......thanks again steve

photoptimist · 01-10-2020, 09:52 AM

Originally posted by Aaron28

no pttl....auto mode setting the iso and fstop which is available on the 360 & 540 and various other flashes that have their own sensor

OK. In that case, you do want to enter an ISO and f-stop combination that is two stops different from the one used on the camera.

Personally, I'd tweak the ISO on the flash by two stops (set ISO 25 on the flash in place of ISO 100 on the camera) because it seems more intuitive that the ND 2 filter making the camera two stops less sensitive to light rather than affecting the lens aperture.

Aaron28 · 01-10-2020, 04:13 PM

Originally posted by photoptimist

OK. In that case, you do want to enter an ISO and f-stop combination that is two stops different from the one used on the camera.
Personally, I'd tweak the ISO on the flash by two stops (set ISO 25 on the flash in place of ISO 100 on the camera) because it seems more intuitive that the ND 2 filter making the camera two stops less sensitive to light rather than affecting the lens aperture.

great thanks! did not think the af360 or af540 can go below 100iso but I have a few other older "auto" flashes that allow or have a distance scale for less than 100iso....I like the idea of adjusting the iso as it would seem easier to keep track of "how many stop differences"

01-09-2020, 05:07 PM	#1
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 7,131	auto flash mode use with ND filter set up? also use with leaf shutters... reckon I could experiment but why not ask...… the af360 or 540 offer auto mode (NOT p-ttl) which iso & fstop can be set and the flash itself determines the exposure.....I like using the mode especially with non'A' lenses and usually get nice results the question (or experiment) to see if the 'theory' is on track is if I get 2 stops from ND filter use from 1/500 down to 1/125(under sync/sync) with 200iso at f2.8 do I input f5.6 at 200iso on the flash to compensate for the 2 stop loss? the idea is to gain confidence in results digitally then translate to film use secondly is it true that sync speed is not necessary when using a leaf shutter (whether rangefinder or TLR) and flash?? have read more than once on various camera reviews that flash could be used at any speed when a leaf shutter is being used thanks Aaron Last edited by Aaron28; 01-09-2020 at 05:30 PM.

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01-09-2020, 05:21 PM	#2
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,122	If the Auto mode is P-TTL (using a preflash to measure how the flash lights the scene), the it will work fine with ND filters. Theoretically, leaf shutters can sync at all speeds. In practice, the time it takes to open the leaf shutter for the fastest shutter times means that the aperture might not be fully opened during the entire flash burst. The result wil be a slight dimming of the flash illumination and a subtle reduction or feathering of any bokeh created by the flash.

01-09-2020, 09:41 PM	#3
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 7,131 Original Poster	Originally posted by photoptimist If the Auto mode is P-TTL (using a preflash to measure how the flash lights the scene), the it will work fine with ND filters. no pttl....auto mode setting the iso and fstop which is available on the 360 & 540 and various other flashes that have their own sensor Originally posted by photoptimist Theoretically, leaf shutters can sync at all speeds. In practice, the time it takes to open the leaf shutter for the fastest shutter times means that the aperture might not be fully opened during the entire flash burst. The result wil be a slight dimming of the flash illumination and a subtle reduction or feathering of any bokeh created by the flash. thanks that kinda backs up and gives more depth to what I have read......reckon it will be experimenting.....again in this scenario was hoping to use the auto mode (setting iso & fstop) on the flash

01-09-2020, 09:45 PM	#4
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by Aaron28 the af360 or 540 offer auto mode (NOT p-ttl) which iso & fstop can be set and the flash itself determines the exposure Originally posted by Aaron28 the question (or experiment) to see if the 'theory' is on track is if I get 2 stops from ND filter use from 1/500 down to 1/125(under sync/sync) with 200iso at f2.8 do I input f5.6 at 200iso on the flash to compensate for the 2 stop loss? That is what I would do and what works when using B&W filters for film. Of course, the easiest way to see is to simply do it as a test. Assuming you have an "auto" flash, give it a try. Originally posted by Aaron28 secondly is it true that sync speed is not necessary when using a leaf shutter (whether rangefinder or TLR) and flash?? It is true that a leaf shutter is not bound by a maximum shutter speed as long as the flash duration is shorter than the shutter duration. Steve

01-09-2020, 09:48 PM	#5
stevebrot Otis Memorial Pentaxian Join Date: Mar 2007 Location: Vancouver (USA) Photos: Gallery \| Albums Posts: 42,007	Originally posted by stevebrot It is true that a leaf shutter is not bound by a maximum shutter speed as long as the flash duration is shorter than the shutter duration. Note that using the "Auto" flash mode manages exposure by varying the duration of the flash. Steve

01-09-2020, 10:13 PM	#6
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 7,131 Original Poster	Originally posted by stevebrot Note that using the "Auto" flash mode manages exposure by varying the duration of the flash. yes that is my understanding as the sensor on the flash turns it off when it reaches it's goal.....i.e. 100iso @ f2.8 or whatever its set at and receives such reflection back to turn off Originally posted by stevebrot Assuming you have an "auto" flash, give it a try yes af360fgz & af540fgz have these modes.....use them often at sync speed with no ND or any filter with nice results......just curious about the manual compensation to adjust for having a ND filter on the lens.......going to experiment but wondering if i am taking the right approach to get started Originally posted by stevebrot That is what I would do and what works when using B&W filters for film. leads me to believe i might be on the right approach to get started......thanks again steve

01-10-2020, 09:52 AM	#7
photoptimist Pentaxian Join Date: Jul 2016 Photos: Albums Posts: 5,122	Originally posted by Aaron28 no pttl....auto mode setting the iso and fstop which is available on the 360 & 540 and various other flashes that have their own sensor OK. In that case, you do want to enter an ISO and f-stop combination that is two stops different from the one used on the camera. Personally, I'd tweak the ISO on the flash by two stops (set ISO 25 on the flash in place of ISO 100 on the camera) because it seems more intuitive that the ND 2 filter making the camera two stops less sensitive to light rather than affecting the lens aperture.

01-10-2020, 04:13 PM	#8
Aaron28 Pentaxian Join Date: Jan 2015 Location: Huntsville, Al Posts: 7,131 Original Poster	Originally posted by photoptimist OK. In that case, you do want to enter an ISO and f-stop combination that is two stops different from the one used on the camera. Personally, I'd tweak the ISO on the flash by two stops (set ISO 25 on the flash in place of ISO 100 on the camera) because it seems more intuitive that the ND 2 filter making the camera two stops less sensitive to light rather than affecting the lens aperture. great thanks! did not think the af360 or af540 can go below 100iso but I have a few other older "auto" flashes that allow or have a distance scale for less than 100iso....I like the idea of adjusting the iso as it would seem easier to keep track of "how many stop differences"