Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Pentax / Samsung dSLR, K Mount Mirrorless

Reply
 
Thread Tools Search this Thread
Old Jul 12, 2006, 1:55 AM   #1
Member
 
Pentaxchamp's Avatar
 
Join Date: Mar 2006
Posts: 34
Default

Ok so I got my SMC Pentax-A 70-210mm, its beautiful and clear and all that good stuff but I have a question. In Av, I can get a very shallow depth of field very easily but I have no idea how to deepen it...That is, the focus area is crisp but other parts are not, I want it all to be in focus. I have done the "2 permitted" for the aperture ring. It seems that I can only have control over the aperture using the lens ring in the manual mode, is that right? The ring did not appear to affect the pictures in Av or Tv...

Any hints on better fine tuning of the dof whether it be shallow or deep are appreciated.

Great lens, now the DL looks like a real man. Er, camera. I am thoroughly pleased with the 150 bones (us) that I shelled out for it. Thanks to all that encouraged. Roy, good luck selling the M200.

Thanks,
-alex


Pentaxchamp is offline   Reply With Quote
Sponsored Links
Old Jul 12, 2006, 2:39 AM   #2
Senior Member
 
bilybianca's Avatar
 
Join Date: Nov 2005
Location: Hassleholm, Sweden
Posts: 3,435
Default

Let see, I'm not quite clear over what your problem is, so forgive me if I explain something that is obvius to you.

If your lenshas the A setting on the aperture ring, always use that and never change aperture on the lens itself. If it's an older lens, without the A, then it's another story. If you use the ring on the lens it will always expose at maximum aperture (giving a shallow DOF) in Av or Tv mode. Only M mode works with the ring.

To get more DOF, you need to stop down the aperture. It can be done in at least three ways:

Put the mode dial (upper left) in Av mode.Turn the e-dial, and check how the aperture changes (you can see the aperture value change in theviewfinder or the LCD panel. The exposure time will also change to keep the exposure right, but if you point the camera in another directionthe aperture will remain the same and the exposure time will change due to changing lighting.

Put the mode dial in Tvmode. Turn the e-dial. Now the exposure time will be set and the aperture value will change due to lighting conditions.

Put the mode dial in M mode. Turn the e-dial,and you will see theexposure time (underlined in theviewfinder) change while the aperture value doesn't. At the right you will also see if the setting will give you under- or overexposure (-3 up to +3).

If you now want to change the aperture (in M mode), just press the Av button (just behind the shutter release button) and you will se how the aperture value gets underlined in the viwfinder, and now is the value that changes if you turn the e-dial.

Hope this was the information you needed. A rather extensive explanation, i learnt all of it by reading the manual.

Kjell
bilybianca is offline   Reply With Quote
Old Jul 12, 2006, 3:31 AM   #3
Senior Member
 
Peacekeeper's Avatar
 
Join Date: Jan 2006
Posts: 1,024
Default

If you are using Av mode you are more than likely setting your aperture too wide, ie. f2.8.

This aperture setting is great for portrait work etc where you want to isolate a person or object from the background as the DOF is shallow and only objects at the same distance from the lens as the object you have focussed on wil be in focus.

Go here to try a simulated cam website to see the effect of shallow DOF.
http://www.photonhead.com/simcam/shutteraperture.php

Where possible F8 or higher will give you a deep DOF for scenery, but depending on the lighting available you might have to drop your shutter speed down to 1/50 sec etc to obtain correct exposure, the joys of monopods and tripods giving you that extra couple of F stops of enjoyment.

I do a lot of night time photography and the most common mistake is having the aperture wide open thinking it will help. 1. Usually your lens is sharper at higher f stops and 2. the DOF is too shallow for sharp scenery shots. Go smaller aperture opening and tripod for this.
Peacekeeper is offline   Reply With Quote
Old Jul 12, 2006, 6:51 AM   #4
Junior Member
 
Join Date: May 2006
Posts: 8
Default

I wonder if there are different content in other's countries manuals, because i read mine and didn't see much of what you wrote, (which was extremely helpful) so thanks.
Joliet Jim is offline   Reply With Quote
Old Jul 12, 2006, 9:30 AM   #5
Senior Member
 
bper's Avatar
 
Join Date: Jan 2006
Location: Washington State
Posts: 454
Default

I think the method outlined by Kjell is for the lenses that have an A setting on them. With the M lenses or old M42 screw mounts, I think you need to use the M setting. At least that is what I have been doing. You can only change the apertureat the lens on these. It's a little different approach, but the end result is the same. Correct me if I am wrong - Bruce
bper is offline   Reply With Quote
Old Jul 12, 2006, 9:50 AM   #6
Senior Member
 
bilybianca's Avatar
 
Join Date: Nov 2005
Location: Hassleholm, Sweden
Posts: 3,435
Default

You're right.

I use fully manual lenses this way (following the instructions in the manual).

Always M mode. Manual lenses without the "A" setting doesn't work in Av or Tv.

Choose aperture with the ring on the lens. (First you have to choose "Allow aperture ring" in the menu). Turn the shutter release button to the right (clockwise), and get a DOF preview (the aperture stops down). Now, in the viewfinder, to the rightyou can also see an indication of over- or underexposure (-3to +3). Change the exposure time with the e-dial or the aperture with the ring on the lens to get the right exposure. Let go of the DOF preview, focus at full apertureand Click! there's your picture. I never use the AE-L button.

Kjell

bilybianca is offline   Reply With Quote
Old Jul 12, 2006, 1:49 PM   #7
Member
 
Pentaxchamp's Avatar
 
Join Date: Mar 2006
Posts: 34
Default

Thanks all, I guess I missed that section when I read the manual cover to cover.
I'll just go with the manual setting more now.

so much better then the kit lens,
-alex
Pentaxchamp is offline   Reply With Quote
Old Jul 12, 2006, 2:31 PM   #8
Senior Member
 
bilybianca's Avatar
 
Join Date: Nov 2005
Location: Hassleholm, Sweden
Posts: 3,435
Default

Pentaxchamp wrote:
Quote:
so much better then the kit lens,
-alex
Yep, it's probably one of the best zooms out there, and better than many primes.

Kjell
bilybianca is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 7:03 AM.