Pentax AF240Z on K20D
Posted 01/10/2009 - 08:38 - Helpful Comment
Link
Have a look here, which will explain the differences.
http://www.bdimitrov.de/kmp/technology/hot-shoe/index.html
On the K20D, Program mode won't work, but Auto mode will, provided you set the camera body to Manual. In my experience, Auto mode works just as well as TTL and P-TTL.
The flash must of course be mounted on the camera for Auto to work.
If using the flash to trigger other flashes, I point it up at the ceiling and set it to Auto to minimise power drain. On Manual it will discharge fully and use the batteries faster.
You might find you need to set the aperture slightly wider than the setting shown on the flash when using Auto.
Auto will of course take account of any diffusers you may wish to put on the flash.
Experimentation is the key.
Good luck.
G
http://www.bdimitrov.de/kmp/technology/hot-shoe/index.html
On the K20D, Program mode won't work, but Auto mode will, provided you set the camera body to Manual. In my experience, Auto mode works just as well as TTL and P-TTL.
The flash must of course be mounted on the camera for Auto to work.
If using the flash to trigger other flashes, I point it up at the ceiling and set it to Auto to minimise power drain. On Manual it will discharge fully and use the batteries faster.
You might find you need to set the aperture slightly wider than the setting shown on the flash when using Auto.
Auto will of course take account of any diffusers you may wish to put on the flash.
Experimentation is the key.
Good luck.
G
Keywords: Charming, polite, and generally agreeable.
Posted 01/10/2009 - 08:47 - Helpful Comment
Link
According to the AF240Z manual, the "P" mode should set the appropriate aperture on the camera (assuming the camera is in P or Green). This may not work on the dSLRs. It's quite a nice feature (for the bodies that work with it) as it eliminates some of the error.
The "A" mode on the flash will require you to manually set the aperture on the camera. Use "Av" or "M" mode on the camera (preferably M).
The "M" mode on the flash will, as you say, discharge a set amount of light. However, the advantage with digital is you can easily do a trial-and-error to get it right.
In all cases, make sure you FIX the ISO setting on the camera! These older flashes were built before auto-ISO existed (Using the "M" mode on the camera fixes the ISO too)
I'd suggest using fully manual on the camera. Set 1/180s on the body, f/8, ISO400 and work from there. You'll probably find the "A" setting on the flash the best for ad-hoc shots.
(You may also find my flash guide a useful addition.)
HTH!
Matt
The "A" mode on the flash will require you to manually set the aperture on the camera. Use "Av" or "M" mode on the camera (preferably M).
The "M" mode on the flash will, as you say, discharge a set amount of light. However, the advantage with digital is you can easily do a trial-and-error to get it right.
In all cases, make sure you FIX the ISO setting on the camera! These older flashes were built before auto-ISO existed (Using the "M" mode on the camera fixes the ISO too)
I'd suggest using fully manual on the camera. Set 1/180s on the body, f/8, ISO400 and work from there. You'll probably find the "A" setting on the flash the best for ad-hoc shots.
(You may also find my flash guide a useful addition.)
HTH!
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
(For gallery, tips and links)
Posted 01/10/2009 - 21:06
Link
George Lazarette wrote:
Have a look here, which will explain the differences.
http://www.bdimitrov.de/kmp/technology/hot-shoe/index.html
On the K20D, Program mode won't work, but Auto mode will, provided you set the camera body to Manual. In my experience, Auto mode works just as well as TTL and P-TTL.
I did before posting my question - but didn't found the information that P mode won't work on K20D - or I assume it just works the same way as A setting looking at the results I achieved (not that I did lots of tests).Have a look here, which will explain the differences.
http://www.bdimitrov.de/kmp/technology/hot-shoe/index.html
On the K20D, Program mode won't work, but Auto mode will, provided you set the camera body to Manual. In my experience, Auto mode works just as well as TTL and P-TTL.
Quote:
Auto will of course take account of any diffusers you may wish to put on the flash.
Experimentation is the key.
Good luck.
G
Thanks Winter's coming so I hope I'll have some time at home for experiments.Auto will of course take account of any diffusers you may wish to put on the flash.
Experimentation is the key.
Good luck.
G
By the way how flash 'knows' about diffusers? I thought that the sensor is below the flash 'window' (how should I name that part?) so it cannot notice any filter on a top of it? Then I wonder how it recalculates the power needed when bouncing the light up?
Kind regards,
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Posted 01/10/2009 - 21:30
Link
MattMatic wrote:
According to the AF240Z manual, the "P" mode should set the appropriate aperture on the camera (assuming the camera is in P or Green). This may not work on the dSLRs. It's quite a nice feature (for the bodies that work with it) as it eliminates some of the error.
I guess it is - shame it doesn't work on K20D According to the AF240Z manual, the "P" mode should set the appropriate aperture on the camera (assuming the camera is in P or Green). This may not work on the dSLRs. It's quite a nice feature (for the bodies that work with it) as it eliminates some of the error.
Quote:
The "A" mode on the flash will require you to manually set the aperture on the camera. Use "Av" or "M" mode on the camera (preferably M).
The "M" mode on the flash will, as you say, discharge a set amount of light. However, the advantage with digital is you can easily do a trial-and-error to get it right.
Ah, just hoped there is a secret way to decrease the flash power in flash manual mode. So the only mode which will allow me to decrease the flash power is A (or use some translucent material like bubble wrap on the flash)?The "A" mode on the flash will require you to manually set the aperture on the camera. Use "Av" or "M" mode on the camera (preferably M).
The "M" mode on the flash will, as you say, discharge a set amount of light. However, the advantage with digital is you can easily do a trial-and-error to get it right.
Quote:
In all cases, make sure you FIX the ISO setting on the camera! These older flashes were built before auto-ISO existed (Using the "M" mode on the camera fixes the ISO too)
I used the flash in M mode but I do not set Auto ISO anyway, so probably I'm on safe side unless I chose TAv mode. Good tip, though In all cases, make sure you FIX the ISO setting on the camera! These older flashes were built before auto-ISO existed (Using the "M" mode on the camera fixes the ISO too)
Quote:
I'd suggest using fully manual on the camera. Set 1/180s on the body, f/8, ISO400 and work from there. You'll probably find the "A" setting on the flash the best for ad-hoc shots.
(You may also find my flash guide a useful addition.)
HTH!
Matt
Thanks for reminding me It's a great source of knowledge. I read it some time ago (when I bought it from you) but then I remembered it was mostly about modern flashes (well, then I thought about buying AF540FGZ). I refreshed my memory today going through it again and enjoyed tips on M and A settings I'd suggest using fully manual on the camera. Set 1/180s on the body, f/8, ISO400 and work from there. You'll probably find the "A" setting on the flash the best for ad-hoc shots.
(You may also find my flash guide a useful addition.)
HTH!
Matt
However, you mentioned there Trailing Curtain Sync mode. Fantastic, I though it is not possible but it works with AF240Z! However it works not as a trailing sync but similar to Slow Sync - it flashes at the beginning, not at the end. Actually, it does the same with Slow Sync. Should it be like that or I do something wrong?
Thanks for the help
Kind regards,
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Posted 02/10/2009 - 09:36 - Helpful Comment
Link
The reason why the flash "knows" about the diffuser in A mode, is that the sensor on the flash is registering the amount of light which hits it (and which will also hit the sensor or film in the camera).
Clearly, a diffuser will reduce the amount of light coming back to the flash sensor, so it will compensate accordingly.
G
Clearly, a diffuser will reduce the amount of light coming back to the flash sensor, so it will compensate accordingly.
G
Keywords: Charming, polite, and generally agreeable.
Posted 02/10/2009 - 09:39
Link
misiek_knm wrote:
I did before posting my question - but didn't found the information that P mode won't work on K20D - or I assume it just works the same way as A setting looking at the results I achieved (not that I did lots of tests).
Unfortunately, Boz's site is no longer updated as comprehensively as it once was. Although he does record new kit, he doesn't also update all the ancillary pages.I did before posting my question - but didn't found the information that P mode won't work on K20D - or I assume it just works the same way as A setting looking at the results I achieved (not that I did lots of tests).
I pointed you in that direction because he explains the principles.
G
Keywords: Charming, polite, and generally agreeable.
Posted 02/10/2009 - 10:32 - Helpful Comment
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Michal,
Slow and Trailing sync are related - they both work with slow shutter speeds. However, Trailing Curtain sync fires the flash at the end of the shutter (so it goes off just before the trailing curtain of the shutter closes). Normal slow sync will open the leading curtain then fire the flash.
It's helpful to think of the design of the shutter unit as a hole with two "blinds". Before you press the button to take the image, both blinds (or curtains) are at the top. When you hit the button, the leading blind drops - opening the sensor (or film) to the image. After the timer expires, the trailing curtain/blind will fall - stopping light from falling on the sensor.
Once the image is taken, both curtains travel to the top of the shutter mechanism to be ready for the next shot.
Being able to do trailing curtain sync is a function of the flash unit itself, not the camera The interaction with a basic flash unit works like this:
* Leading curtain falls
* Flash contacts are shorted
* Timer
* Flash contacts are released
* Trailing curtain falls
Normally the flashgun will fire when the contacts are shorted - leading curtain sync.
With appropriate electronics in the flashgun itself it can be set to fire the light when the flash contacts are released (having been shorted first).
Does that makes sense? (Sorry if it's waffly )
Matt
Slow and Trailing sync are related - they both work with slow shutter speeds. However, Trailing Curtain sync fires the flash at the end of the shutter (so it goes off just before the trailing curtain of the shutter closes). Normal slow sync will open the leading curtain then fire the flash.
It's helpful to think of the design of the shutter unit as a hole with two "blinds". Before you press the button to take the image, both blinds (or curtains) are at the top. When you hit the button, the leading blind drops - opening the sensor (or film) to the image. After the timer expires, the trailing curtain/blind will fall - stopping light from falling on the sensor.
Once the image is taken, both curtains travel to the top of the shutter mechanism to be ready for the next shot.
Being able to do trailing curtain sync is a function of the flash unit itself, not the camera The interaction with a basic flash unit works like this:
* Leading curtain falls
* Flash contacts are shorted
* Timer
* Flash contacts are released
* Trailing curtain falls
Normally the flashgun will fire when the contacts are shorted - leading curtain sync.
With appropriate electronics in the flashgun itself it can be set to fire the light when the flash contacts are released (having been shorted first).
Does that makes sense? (Sorry if it's waffly )
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
(For gallery, tips and links)
Posted 02/10/2009 - 10:36
Link
Just an update on the "How does the camera know how much light" question:
As George points out, the light sensor in the body of the flash unit measures the reflected light to judge how much light to release. If you put a diffuser, or bounce the flash, the "eye" of the flash still points towards the subject.
Just make sure that the "eye" isn't obscured. If, for instance, you put a huge oversized diffuser on the flash that covered the xenon tube AND the "eye" then the result will be overexposure for the camera (because the camera sensor and "eye" will be looking at the subject in different ways).
Likewise, if the flash is mounted off-camera, the "eye" still must point towards the subject.
Additionally, if the subject is very close, or very far away, then the angle of view through the flash's "eye" could be very different from the view for the camera - and exposure issues could result.
Matt
As George points out, the light sensor in the body of the flash unit measures the reflected light to judge how much light to release. If you put a diffuser, or bounce the flash, the "eye" of the flash still points towards the subject.
Just make sure that the "eye" isn't obscured. If, for instance, you put a huge oversized diffuser on the flash that covered the xenon tube AND the "eye" then the result will be overexposure for the camera (because the camera sensor and "eye" will be looking at the subject in different ways).
Likewise, if the flash is mounted off-camera, the "eye" still must point towards the subject.
Additionally, if the subject is very close, or very far away, then the angle of view through the flash's "eye" could be very different from the view for the camera - and exposure issues could result.
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
(For gallery, tips and links)
Posted 02/10/2009 - 23:06
Link
George Lazarette wrote:
The reason why the flash "knows" about the diffuser in A mode, is that the sensor on the flash is registering the amount of light which hits it (and which will also hit the sensor or film in the camera).
Clearly, a diffuser will reduce the amount of light coming back to the flash sensor, so it will compensate accordingly.
G
The reason why the flash "knows" about the diffuser in A mode, is that the sensor on the flash is registering the amount of light which hits it (and which will also hit the sensor or film in the camera).
Clearly, a diffuser will reduce the amount of light coming back to the flash sensor, so it will compensate accordingly.
G
Quote:
(Matt)
As George points out, the light sensor in the body of the flash unit measures the reflected light to judge how much light to release. If you put a diffuser, or bounce the flash, the "eye" of the flash still points towards the subject.
... cut ...
Matt
I see! Thanks for the explanations, now it makes sense to me!(Matt)
As George points out, the light sensor in the body of the flash unit measures the reflected light to judge how much light to release. If you put a diffuser, or bounce the flash, the "eye" of the flash still points towards the subject.
... cut ...
Matt
Quote:
(George)
I pointed you in that direction because he explains the principles.
G
Appreciated, and even though I've been already there, you couldn't know that. Nevertheless the link is worth mentioning for reference if someone will look for similar information. Thanks for additional explanations too, very useful, now I understand my new flash better.
(George)
I pointed you in that direction because he explains the principles.
G
Kind regards,
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Posted 02/10/2009 - 23:17
Link
MattMatic wrote:
Being able to do trailing curtain sync is a function of the flash unit itself, not the camera The interaction with a basic flash unit works like this:
* Leading curtain falls
* Flash contacts are shorted
* Timer
* Flash contacts are released
* Trailing curtain falls
Normally the flashgun will fire when the contacts are shorted - leading curtain sync.
With appropriate electronics in the flashgun itself it can be set to fire the light when the flash contacts are released (having been shorted first).
Does that makes sense? (Sorry if it's waffly )
Matt
Another aaahaaaa!Being able to do trailing curtain sync is a function of the flash unit itself, not the camera The interaction with a basic flash unit works like this:
* Leading curtain falls
* Flash contacts are shorted
* Timer
* Flash contacts are released
* Trailing curtain falls
Normally the flashgun will fire when the contacts are shorted - leading curtain sync.
With appropriate electronics in the flashgun itself it can be set to fire the light when the flash contacts are released (having been shorted first).
Does that makes sense? (Sorry if it's waffly )
Matt
I can imagine how curtains work - I have seen that in my Zenit long time ago (once I wanted to see what's happening when I press the shutter, so I opened the back (no film, obviously) and tried with slow shutter speed (1/30s, B), quite interesting). I believe it is similar then.
But I thought it is camera which triggers the flash in the proper time - ha! I was wrong. So this means that AF240Z has no trailing curtain capability - it fires instantly. It still allows leading curtain sync which is enough for some experiments I plan
Excellent explanation, you should add it to your guide v.2 - thanks again!
Kind regards,
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z
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535 posts
18 years
Grantham,
UK
I know it's not TTL, so far so good - it wouldn't work on K20D anyway. But it has 3 modes:
P (Program)
A (Auto)
M (Manual)
Now I've read the manual and looked at some archival posts, but still cannot make any difference between A and P apart of aperture setting (4.0 or 5.6). The manual says that in P mode flash should set aperture - but in the fact it doesn't. Both A and P mode seem to work in the same way, they don't touch aperture at all, while set shutter to 1/80s in (camera) Av mode and 1/180s i (camera) M mode (but then I can change it). In these 2 settings flash power is adjusted to the camera settings and flash angle.
In flash M mode it always fires with full power and I have to compensate with camera settings (aperture, ISO and shutter) - I can use the tables at flash's back to calculate the numbers. There is no way to modify the flash power.
Do I misunderstand / miss something?
Michal R. Hoffmann
K20D, DA 16-45mm, A 50mm F/1:1.4, DA 55-300mm; flash Pentax AF240Z