Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-07-2009, 11:38 AM   #1
Veteran Member




Join Date: Feb 2008
Location: Michigan
Posts: 307
Should I really care where my aperture is at?

Probably didn't even spell aperature correctly, but is there a certain range where it's better to have the aperture?

K100D with standard 18-55 kit lens. You're standing outside on a nice day and want to take a picture of a diet coke (some of you have seen this story before!!) can. ISO on camera is set to 200. I like to shoot in TV mode since I seem to have a better "feel" for what the camera will do and what result I will obtain.

But other than depth of field, what's the best place to put the shutter speed? I can shoot at 60, and get a nice picture, and with the stabilation on, probably blur free. I'll also get quite a bit of depth of field, which in this case, I don't care one way or the other.

I can also shoot the diet coke can at 500 shutter speed, and probably not get the aperture light to blink at me. Results would still probably be good. Nice crisp photo with no blur, but very little depth of field (once again, in this test, I don't care about depth of field).

In both shots, the aperture would probably about be at the extremes, just inside the blinking aperture light.

I can also shoot at 250 shutter speed, or, "middle of the road", which to me, would give a blur free shot, decent depth of field, and the aperture would probably be somewhere "middle of the road."

So........after all of that..........where do I want my aperture setting if I want the sharpest picture for the object I'm shooting? Wide open, closed down, or middle of the road?

Thank.

vmax84

07-07-2009, 11:49 AM   #2
Veteran Member




Join Date: Jun 2009
Location: Philadelphia
Posts: 478
Generally speaking, most lenses are their sharpest stopped down a bit. F8.0 is a good ball park give or take a stop or two. However it isn't that simple since each lens has it's own characteristics and sweet spot. It sounds like aperture priority may be more beneficial for the example you are making - especially considering it is a static object.
07-07-2009, 12:28 PM   #3
Veteran Member
KungPOW's Avatar

Join Date: Nov 2007
Location: Vancouver, Canada
Photos: Gallery
Posts: 1,702
Here is a link to a test of your lens: Pentax Lens: Zooms - Pentax 18-55mm f/3.5-5.6 SMC P-DA (Tested) - SLRgear.com!

If you have a look at the blur index you see the 18-55 is sharpest at 45mm F11

Also use the lens hood, it will increase contrast and sharpness. Someone on this forum had a great post showing his tests. I was suprised at the difference it made. If I can find it again, I'll post a link.

All exposures are a mix of three settings:

Aperture: controls depth of field and sharpness
Shutter: controls motion blur and camera shake blur
ISO: controls image noise

All photos are a mix of compromises:

High ISO allows a faster shutter and a larger f stop, but produces more noise

Low ISO requires a slower shutter to allow a larger f stop, and produces more image blur

For any one "coke can photo opertunity", there is only one exposure, but many mixes of ISO, aperture, and shutter speed.
07-07-2009, 12:59 PM   #4
Pentaxian
Just1MoreDave's Avatar

Join Date: Feb 2007
Location: Aurora, CO
Photos: Gallery | Albums
Posts: 4,864
Yes, because aperture has a huge effect on how a photo looks.

In a static scene, shutter speed just has to be high enough to avoid shake. Shutter speed is more critical to capture subjects in motion properly. But otherwise it's just a number that works with the aperture.

Aperture affects light, depth of field and sharpness. You can almost always see immediate differences between a photo taken at f2 or at f11. The right aperture can be the difference between a great photo and a bad one.

07-07-2009, 01:42 PM   #5
Veteran Member




Join Date: Feb 2008
Location: Michigan
Posts: 307
Original Poster
QuoteOriginally posted by Just1MoreDave Quote
Yes, because aperture has a huge effect on how a photo looks.

In a static scene, shutter speed just has to be high enough to avoid shake. Shutter speed is more critical to capture subjects in motion properly. But otherwise it's just a number that works with the aperture.

Aperture affects light, depth of field and sharpness. You can almost always see immediate differences between a photo taken at f2 or at f11. The right aperture can be the difference between a great photo and a bad one.

So how do you know where you want the aperture?

vmax84
07-07-2009, 01:47 PM   #6
Veteran Member




Join Date: Jun 2009
Location: Philadelphia
Posts: 478
Vmax...

If I were you, I'd spend some time looking up f-stops and depth of field. Wikipedia has some concise explanations. If you have a thorough understanding of the concepts and realize where your lens is the sharpest, you should be able to answer your own question.
07-07-2009, 02:05 PM   #7
Veteran Member
heliphoto's Avatar

Join Date: May 2008
Location: Region 5
Photos: Gallery
Posts: 2,540
QuoteOriginally posted by Just1MoreDave Quote
Yes, because aperture has a huge effect on how a photo looks.

In a static scene, shutter speed just has to be high enough to avoid shake. Shutter speed is more critical to capture subjects in motion properly. But otherwise it's just a number that works with the aperture.

Aperture affects light, depth of field and sharpness. You can almost always see immediate differences between a photo taken at f2 or at f11. The right aperture can be the difference between a great photo and a bad one.
Which is why so many folks on this forum will tell you their camera lives in Av (aperture priority) mode.


QuoteOriginally posted by vmax84 Quote
So how do you know where you want the aperture?

vmax84
My advice would be to experiment often and review your results with an eye to the effects of different apertures. To me, this is the real advantage of learning photography on a digital setup - instant feedback on the LCD, and virtually free "film" (let's face it, you'll upgrade the body before you shoot 100,000 frames or whatever the projected life of the shutter/mirror is).

A good exercise would be to set your camera to Av mode, and spend a day making every shot a series in full aperture stops between wide open and say f/16 (if feasible) - that is to say, compose the shot of the coke can, and then shoot it at f/3.5, f/5.6, f/8, f/11, and f/16... Then at the end of the day (or the end of the hour) you can review all those shots and see the differences caused by varying the aperture.
07-07-2009, 02:08 PM   #8
Veteran Member




Join Date: Apr 2008
Location: Minnesota
Photos: Gallery
Posts: 1,530
QuoteOriginally posted by vmax84 Quote
So how do you know where you want the aperture?

vmax84
I, along with with many others here, would recommend this book:

Amazon.com: Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera (Updated Edition): Bryan Peterson: Books

Sometimes the best way to learn is by doing. Line up 5 items on a table like this:
Code:
          0
0
0
0
0

X <-- Camera
Now take a picture in Av mode with the aperture at say F16, and then again at f8 and then again at f4.5 all at 55mm. You will see pretty clearly what effect apertures have on an image.

07-07-2009, 02:13 PM   #9
Ash
Community Manager
Loyal Site Supporter
Ash's Avatar

Join Date: Mar 2007
Location: Toowoomba, Queensland
Photos: Gallery | Albums
Posts: 22,695
But if you had a 'choice' between using a large or a small aperture for a subject that would be sharp in either setting, then it depends on how you want your background to turn out in the image. You want it blurry, but still retain some detail for it to be discernible, choose a smaller aperture. You want it completely blurred out so the background is like smeared paint on a wall, you choose a larger aperture.

As mentioned, sharpness of lenses, particularly at the edges dissipates at the largest apertures, so this should be considered as well.
07-07-2009, 02:34 PM   #10
Veteran Member




Join Date: Feb 2008
Location: Michigan
Posts: 307
Original Poster
Ok, enough enough........close this thread!!!!!! I've got enough information now, it's starting to ooze out of my ears!!

Just kidding on closing the thread. Great info and it really gives me some good places to do some research.

Thanks a lot.

vmax84
07-07-2009, 02:36 PM   #11
Veteran Member




Join Date: Feb 2008
Location: Michigan
Posts: 307
Original Poster
The remark "many members keep their camera set up in AV mode most of the time" made me laugh.......I'm always doing stuff backwards since my camera is kept in TV mode most of the time.

And just when I thought I had it all figured out.......... hahahahaha!!

vmax84
07-07-2009, 02:48 PM   #12
Veteran Member




Join Date: Jun 2009
Location: Philadelphia
Posts: 478
QuoteOriginally posted by vmax84 Quote
The remark "many members keep their camera set up in AV mode most of the time" made me laugh.......I'm always doing stuff backwards since my camera is kept in TV mode most of the time.

And just when I thought I had it all figured out.......... hahahahaha!!

vmax84
It's not backwards. While I shoot 90% of the time in aperture priority, I know one very successful photographer that primarily shoots in shutter priority. The trick is knowing how each works and deciding what works best for you (or at least that particular situation).
07-07-2009, 03:06 PM   #13
Veteran Member




Join Date: Feb 2008
Location: Michigan
Posts: 307
Original Poster
QuoteOriginally posted by joeyc Quote
It's not backwards. While I shoot 90% of the time in aperture priority, I know one very successful photographer that primarily shoots in shutter priority. The trick is knowing how each works and deciding what works best for you (or at least that particular situation).
So I do have it all figured out???!!!!

vmax84

Thanks again.
07-07-2009, 03:24 PM   #14
Veteran Member
heliphoto's Avatar

Join Date: May 2008
Location: Region 5
Photos: Gallery
Posts: 2,540
QuoteOriginally posted by joeyc Quote
It's not backwards. While I shoot 90% of the time in aperture priority, I know one very successful photographer that primarily shoots in shutter priority. The trick is knowing how each works and deciding what works best for you (or at least that particular situation).
This is absolutely the case, since a good exposure is a good exposure regardless of how it's obtained... I mostly shoot landscapes and I have a tripod with me (or I can boost ISO if hand holding), so my primary concern is finding the depth of field I'm looking for, and the best performance that the lens can give me, both determined by aperture, hence Av for me...
07-07-2009, 03:45 PM   #15
Veteran Member




Join Date: Feb 2008
Location: Michigan
Posts: 307
Original Poster
I guess my thinking on the depth of field, and why I shoot in Tv mode is if I want a large depth of field, I shoot a slow shutter speed.......if I want a narrow depth of field, I shoot at a higher shutter speed.

Yeah, I know.......go do some reading and hands on with the camera. :-) I guess there are worse things to do with a little bit of ones spare time, huh?!!

vmax84
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!
aperture, blur, camera, care, depth, diet, field, light, pentax help, photography, picture, shutter
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Obama's health care law will increase the nation's health care costs Artesian General Talk 187 05-20-2010 10:18 AM
Streets Does He Care? hockmasm Photo Critique 8 05-18-2010 11:47 PM
Health Care for Everyone... NOT!!!! Fl_Gulfer General Talk 235 12-17-2009 06:40 AM
How we are going to do this? Health Care Russell-Evans General Talk 196 09-22-2009 06:23 PM
Take care Oz eBay Buyers wwwmorrell General Talk 16 04-12-2009 11:32 PM



All times are GMT -7. The time now is 01:33 AM. | 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