Alexander Grigolia wrote:
Could I please have some user comments on the Pentax-FA* 28-70mm f/2.8
AL zoom lens? Not lens test results. But "in the field" working thoughts.
Ease of manual focus. Balance on the camera. Quality of construction.
REPLY:
In my opinion (I know many would disagree and have had no problems) this is the one
Pentax lens that should never have been made. Its very delicate lens and quality of
construction is compromised. This is for two reasons: 1) Power zoom and 2) auto focus.
Normally, these feature shouldn't be disastrous in themselves but some smart bean
counter at Pentax figured out that they wouldn't cost inner focusing on this lens. As
a result, focusing is done by moving the whole front tube of the lens. Because theres
so much to move, the front lens tube is made of plastic to save weight. This means
also plastic filter thread. It also means a rotating front element and filter thread
something thats a pain in the ass when using Cokin filter system and polarizers. It
also means that the power zoom has to move all elements and lens tubes something in
most cases don't manage if not the lens is pointed downwards and thereby get help from
gravity. Many samples (most?) are unable to power zoom past the 35mm setting.
My lens in particular had constant recurring problems; 1) the zoom scale window was
loose (of course). 2) The button for powerzoom got stucked in the "in" position. This
needed to be repared (several times - I believe three or four - actually the lens
needs to be sent to Belgium because most Pentax centers can't repair it, or more
correctly; can't open it. Its too complicated). 3) The lens refused to stop down
atomatically during exposure. 4) Power zoom may stop completely after using it a few
times. Then it worked again after the lens "rested" for about one hour (actually this
freak sympthom was disbelieved by the repairman. After he managed to induce the same
behaviour after testing it, he was completely astonished - solution to this mystery
below). These problems were never fixed. That is, they were fixed but keept on comping
back.
Alexander:
Or the ultimate satisfaction question: If someone stole the lens would
you purchase another one?
REPLY:
Are you Joking. After two years I throw mine litterally in the garbage.
[Before throwing it away I dissasembled it. I finally found out why they (Belgium)
never where able to fix it. It was designed in a way that auto stopdown and power zoom
couldn't work simultaneously. You have to choose one or the other. I found out that
the power zoom contacts touched the aperture mechanism so that it prevented the lens
to stop down by the spring action. If you bent the power zoom contacts away from the
aperture mechanism then they wouldn't couple to the power zoom contacts on the lens
mount then giving no electricity to the lens.]
I'm sure some people are happy with it. However, you wanted real field experience;
here is mine. Oh..its great optically...
Pål
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