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12-26-2010, 06:53 AM   #1
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Unable to increase the shutter speed in Manual mode.

Hi Experts,
I'm new to SLR field and i've purchased a Pentax K-r recently. The problem waht I faced is, i'm not able to increase the shutter speed in Manual Mode(M).I tried to take few shots in poor lit condition with the built-in flash. But the maximum shutter speed is fixed to 180(I believe). Because of this, all my photographs become over exposed and when I turn off the flash, i've to reduce the speed and inturn a blurred image. I tried with both my manual and kit lens but the result is same. Can somebody help me on this issue.
Thanks a lot for your help,
Cheers,
Vass.

12-26-2010, 08:09 AM   #2
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You can not flash with speeds faster than 1/180 (the so-called X-sync).

You have to use your aperture to control the amount of light from the flash (see camera manaul how to calculate).
12-26-2010, 08:13 AM - 1 Like   #3
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The longer answer:

you can only use flash with shutter speeds slower than or equal to the X-sync speed. Reason is that the X-sync speed is the fastest speed at which both curtains of the shutter are fully open. If you use faster speeds, the shutter will already be closing when the flash fires resulting in an image that is partially underexposed / black.

HighSpeed Sync is a way to use faster shutter speeds with flash.


PS: this is not a K-r question.
12-26-2010, 01:52 PM   #4
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QuoteOriginally posted by sterretje Quote
The longer answer:

you can only use flash with shutter speeds slower than or equal to the X-sync speed. Reason is that the X-sync speed is the fastest speed at which both curtains of the shutter are fully open. If you use faster speeds, the shutter will already be closing when the flash fires resulting in an image that is partially underexposed / black.

HighSpeed Sync is a way to use faster shutter speeds with flash.


PS: this is not a K-r question.
Excellent explanation!! Thanks a lot. As you said, if we control the Aperture in this case, what about the DOF? If I want to take a close up portrait and if I increase the Aperture value(say, 16 or 22), it can't give the Blurred background image(As per the theory). Is there any way to increase the shutter speed? Also, I found there are two flash modes only enabled(Manual flash and manual flash with red-eye reduction)-when I use manual lens.
Thanks for your understanding,
Cheers,
Vass.

12-26-2010, 02:03 PM   #5
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With lenses that do not have an A position on the aperture ring the built-in flash fires at full power so the only options to control the exposure from the flash are aperture and ISO. The actual flash pulse is way shorter than the 1/180s the shutter can manage to keep the whole frame exposed so you cannot control exposure with shutter time except for the ambient light that happens to be available. With lenses with the A position set to that (and lenses without an aperture ring) the body cuts the flash pulse short based on metered light so these are more convenient.
12-26-2010, 03:16 PM   #6
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QuoteOriginally posted by jolepp Quote
With lenses that do not have an A position on the aperture ring the built-in flash fires at full power so the only options to control the exposure from the flash are aperture and ISO. The actual flash pulse is way shorter than the 1/180s the shutter can manage to keep the whole frame exposed so you cannot control exposure with shutter time except for the ambient light that happens to be available. With lenses with the A position set to that (and lenses without an aperture ring) the body cuts the flash pulse short based on metered light so these are more convenient.
So kind of you. I don't know about this.So, better to have the manual lens with A position.Could you please suggest few best budget lens of these kind(primes and macro), can be fit on my Pentax K-r.
Thanks for your valuable info.
Regards,
Vass.
12-26-2010, 03:26 PM - 1 Like   #7
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Some nice and inexpensive lenses with the A-position would be the Pentax-A 50mm 1:1.7 and the Cosina 100mm 1:3.5 macro. Another option would be getting an inexpensive external flash where you can control the output to match a desired aperture. With this you can use all kinds of lenses (and the results will be much nicer if you bounce the light via the ceiling or a wall, for this a tilt&swivel head is needed).
12-26-2010, 03:51 PM - 2 Likes   #8
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This may help:

In a few words: (1) you can't go over the flash sync speed; (2) by slowing shutter speed you add more ambient light, no change in flash exposure; (3) to control flash exposure control either flash power output (if possible), aperture, or ISO; (4) combine all this to get the results you need.

12-27-2010, 09:04 AM   #9
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Thank you so much. Also, the video tutorial is so nice. Thanks to Ivan Glisin.
Best Regards,
Vass.
12-27-2010, 10:06 AM   #10
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Nice find.

QuoteOriginally posted by Ivan Glisin Quote
This may help:
http://www.youtube.com/watch?v=Xnn5nzPvoIM

In a few words: (1) you can't go over the flash sync speed; (2) by slowing shutter speed you add more ambient light, no change in flash exposure; (3) to control flash exposure control either flash power output (if possible), aperture, or ISO; (4) combine all this to get the results you need.
12-31-2010, 03:41 AM   #11
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Yes, it is a great tutorial series. I see they went over episode 40 now. I would recommend everyone to watch episodes of "Photography 1 on 1", probably the best (mostly studio flash) photo tutorials on YouTube, now sponsored by Adorama:

http://www.youtube.com/user/snapfactory
01-03-2011, 12:05 PM   #12
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QuoteOriginally posted by Ivan Glisin Quote
Yes, it is a great tutorial series. I see they went over episode 40 now. I would recommend everyone to watch episodes of "Photography 1 on 1", probably the best (mostly studio flash) photo tutorials on YouTube, now sponsored by Adorama:

http://www.youtube.com/user/snapfactory
Delighted to read that you're enjoying it - I'll let Mark know.


♫★Best wishes for a Happy, Healthy and Prosperous New Year ★♫
01-03-2011, 04:29 PM   #13
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QuoteOriginally posted by Helen Oster Quote
Delighted to read that you're enjoying it - I'll let Mark know.
Great Helen, please do so! The series is a great resource, keep new episodes coming.
01-03-2011, 06:40 PM   #14
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QuoteOriginally posted by Helen Oster Quote
Delighted to read that you're enjoying it - I'll let Mark know.
Add another to the fan club.
QuoteOriginally posted by Helen Oster Quote

♫★Best wishes for a Happy, Healthy and Prosperous New Year ★♫
Thanks and all the same back to you.
01-04-2011, 12:22 AM   #15
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QuoteOriginally posted by bogiesbad Quote
Add another to the fan club.


I love the videos, too, and thanks to the simplicity and conciseness of Mark's explanations am finally progressing from being an enthusiastic amateur to actually beginning to understand what I might be capable of!
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