DAL 18-55mm 3.5-5.6 3.5 midway only

Dudley Dorite · 08-25-2010, 07:20 AM

I have only had the K-x, my first SLR, for 3 weeks and have been experimenting, so please excuse my stupid questions.
I have been trying to set the maximum aperture to 3.5f at the widest angle of my 18-55mm 3.5-5.6 DAL lens but only 5.6f is selectable in aperute priority.
Being new to this level of photography I get confused.
The lens will contract in as I widen the view and the starts to move out once again as I continue to expand the view to the widest angle.
I can select 3.5f at the point where the lense is closest to the camera about half way through the zoom range but if If I move the lens to a wider angle the aperture changes to 5.6f.
Is this correct or am I missing something? Or is there is a fault with either the camera or the lens?
I suspect it is me I just do not know enough to understand what I am doing wrong.
Any response welcome.

**Kerrowdown** · 08-25-2010, 11:38 AM

Welcome to the forum, don't worry too much about lens physically going in and out.

Just look through the viewfinder at the wide end (18mm) you will get a lot more in the picture and this will be the f3.5 end also. As you move towards the 55mm end the f5.6 will then come into play.

Dudley Dorite · 08-26-2010, 01:01 AM

I had another play last night and I could set 3.5f at 35mm in aperture priority mode and move the lens to 18mm with 3.5f staying; however as soon as I pre-focussed it jumps back to 5.6f! Undeterred I changed to manual mode and set the lens to 18mm and I was able to set 3.5f in this mode and pre-focus without it changing. So I then changed back to aperture priority and it now functions as I would expect, setting 3.5f at 18mm changes to higher numbers as I zoom in and revduces back as I zoom out. I suspect this is a software bug?

08-25-2010, 07:20 AM	#1
Dudley Dorite New Member Join Date: Aug 2010 Location: Welwyn Garden City, Herts Photos: Gallery Posts: 12	DAL 18-55mm 3.5-5.6 3.5 midway only I have only had the K-x, my first SLR, for 3 weeks and have been experimenting, so please excuse my stupid questions. I have been trying to set the maximum aperture to 3.5f at the widest angle of my 18-55mm 3.5-5.6 DAL lens but only 5.6f is selectable in aperute priority. Being new to this level of photography I get confused. The lens will contract in as I widen the view and the starts to move out once again as I continue to expand the view to the widest angle. I can select 3.5f at the point where the lense is closest to the camera about half way through the zoom range but if If I move the lens to a wider angle the aperture changes to 5.6f. Is this correct or am I missing something? Or is there is a fault with either the camera or the lens? I suspect it is me I just do not know enough to understand what I am doing wrong. Any response welcome.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
For Sale - Sold: DAL 18-55mm and DAL 50-300mm (US)	happygui	Sold Items	6	08-25-2010 01:22 PM
For Sale - Sold: K20D - DBG Grip - DA18-55mm WR - 18-55mm DAL	VaughnA	Sold Items	7	03-13-2010 05:40 PM
Question about DAL 18-55mm	Ed n Georgia	Pentax SLR Lens Discussion	10	01-09-2010 10:46 PM
DA 18-55mm AL II vs DAL 18-55mm (kit lens) vs DA 18-55mm WR	rustynail925	Pentax SLR Lens Discussion	10	01-08-2010 02:06 PM

08-25-2010, 11:38 AM	#2
Kerrowdown PEG Moderator Join Date: Aug 2008 Location: Highlands of Scotland... "Hold Infinity in the palm of your hand" - William Blake Photos: Gallery Posts: 57,819	Welcome to the forum, don't worry too much about lens physically going in and out. Just look through the viewfinder at the wide end (18mm) you will get a lot more in the picture and this will be the f3.5 end also. As you move towards the 55mm end the f5.6 will then come into play.

08-26-2010, 01:01 AM	#3
Dudley Dorite New Member Join Date: Aug 2010 Location: Welwyn Garden City, Herts Photos: Gallery Posts: 12 Original Poster	I had another play last night and I could set 3.5f at 35mm in aperture priority mode and move the lens to 18mm with 3.5f staying; however as soon as I pre-focussed it jumps back to 5.6f! Undeterred I changed to manual mode and set the lens to 18mm and I was able to set 3.5f in this mode and pre-focus without it changing. So I then changed back to aperture priority and it now functions as I would expect, setting 3.5f at 18mm changes to higher numbers as I zoom in and revduces back as I zoom out. I suspect this is a software bug?