Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
03-14-2015, 03:59 AM   #1
Senior Member




Join Date: Jul 2010
Posts: 271
When your camera adjusts its shutter speed to the selected focus length?

AFAIK I've found that camera function in my K5 IIs (which I no longer own), that was a play of ambient light and flash fill-in
To save RTFM (and to let know others here) at which menu/program setting your K-3 body adjusts shutter speed to the focal length when shooting with the prioprietary zoom lens?

03-14-2015, 05:51 AM   #2
Pentaxian
Kozlok's Avatar

Join Date: Jun 2012
Location: Albuquerque
Photos: Gallery
Posts: 1,801
Shutter speed changes with Aperture, not focal length. Some zoom lenses change aperture when you zoom them. In reality, the aperture changes smoothly as you zoom, but the electronics in the lens tell the camera what the aperture is set to only approximately, which is why it looks like it changes in jumps. The changing aperture as you zoom causes the shutter speed to change each time the indicated aperture changes. So this is lens dependent, not camera dependent. This assumes you set the aperture at its widest setting (smallest f number). It will also happen in green and program mode. In this case, it depends on the lens and whatever the light is. No way to answer your question.

If you choose AV and choose a higher f number, the shutter speed won't change when you zoom. I don't recommend shooting always at high f numbers, but it will keep the shutter speed from changing.

It looks like you need to learn the basics of exposure and get control over your photography. Try reading a book by Peterson called "Understanding Exposure" Link. There are other similar books, but that's the one I read and I liked it.
03-14-2015, 06:39 AM   #3
Veteran Member




Join Date: Sep 2012
Photos: Gallery | Albums
Posts: 1,728
QuoteOriginally posted by Prakticant Quote
AFAIK I've found that camera function in my K5 IIs (which I no longer own), that was a play of ambient light and flash fill-in
To save RTFM (and to let know others here) at which menu/program setting your K-3 body adjusts shutter speed to the focal length when shooting with the prioprietary zoom lens?
Are you referring to minimum shutter speed for a focal length? If yes, go to shooting tab 2 and then select ISO Sensitivity AUTO Setting. You can choose Fast, Medium, or Slow. This tells the camera whether you favor fast, medium, or slow shutter speeds at any given focal length.
03-14-2015, 07:21 AM   #4
Senior Member




Join Date: Jul 2010
Posts: 271
Original Poster
I've read (in a manual? in an article?) how Pentax camera body (I do not remember the camera model) adjusts shutter speed to the selected focal length of the zoom, ie. 1/125 for 50mm, 1/300 for 135mm (these values now are an example).
I did not use that function as I thought shutter speed was to short for my camera & lens handling (I preferred longer exposures).
With K-3 I'd like to choose in general shorter exposures (K-3, due to more MPix, is more vulnerable to camera shake), so the above auto function might be OK at least as for me.
Guys, which Pentax DSLR model did the above auto shutter setting: K10d? K5 IIs? K-3?

ADDED:
I got it, guys:
Set your camera to Av.
Put your AF-540FGZ flash (the trick works also with Sigma EF-610 DG Super) on the camera in P-TTL or Auto mode (Auto might be tricky with ISO/f-stop setting).
Set your in-camera flash setting (4-way controller) to Flash On (not Slow Speed Sync, not Trailing Curtain Sync).
Put a zoom lens (I guess Pentax DA*, DA, or FA zoom lens).
Now your Pentax camera adjusts shutter speed when you adjust your zoom focal length.

-----
QuoteOriginally posted by IchabodCrane Quote
Are you referring to minimum shutter speed for a focal length? If yes, go to shooting tab 2 and then select ISO Sensitivity AUTO Setting. You can choose Fast, Medium, or Slow. This tells the camera whether you favor fast, medium, or slow shutter speeds at any given focal length.



Last edited by Prakticant; 03-14-2015 at 11:13 AM.
03-14-2015, 09:54 AM   #5
Veteran Member




Join Date: Jan 2015
Location: Salt Lake City, Utah
Photos: Albums
Posts: 305
QuoteOriginally posted by Prakticant Quote
AFAIK I've found that camera function in my K5 IIs (which I no longer own), that was a play of ambient light and flash fill-in
To save RTFM (and to let know others here) at which menu/program setting your K-3 body adjusts shutter speed to the focal length when shooting with the prioprietary zoom lens?

Ok maybe I'm old (27) but I prefer words to acronyms. I figured out AFAIK but I have no idea what RTFM means...
03-14-2015, 10:01 AM   #6
Veteran Member




Join Date: Sep 2012
Photos: Gallery | Albums
Posts: 1,728
QuoteOriginally posted by Zephos Quote
Ok maybe I'm old (27) but I prefer words to acronyms. I figured out AFAIK but I have no idea what RTFM means...
RTFM = Read the *** Manual
03-14-2015, 11:17 AM   #7
Senior Member




Join Date: Jul 2010
Posts: 271
Original Poster
RTFM = Read That Flash Manual

Actually in that case, Read That Flash Manual .

-----
QuoteOriginally posted by IchabodCrane Quote
RTFM = Read the *** Manual
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
camera, dslr, k-3, k3, pentax k-3, shutter
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Spoiled by SR! [Post your low shutter speed photographs] carrrlangas Photographic Technique 4 06-22-2014 07:22 PM
Newbie, how to balance ISO vs. shutter speed in the moment? Newtophotos Photographic Technique 10 08-22-2013 07:48 AM
Where to look when the camera tells you your exposure settings are correct? haycyn Troubleshooting and Beginner Help 7 05-16-2013 09:41 AM
[K20D] Does your SR icon light up when using the AF button to focus? Reportage Pentax DSLR Discussion 4 09-18-2010 10:46 PM
Shutter speed vs focal length Judd Troubleshooting and Beginner Help 13 12-12-2009 06:01 AM



All times are GMT -7. The time now is 08:07 PM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top