automatic setting


ggsupersport

Link Posted 30/06/2012 - 16:01
I have the Pentax 18-250 lens (that is no longer available) that I use on my Pentax K20 . I am a true amateur, but got GREAT photos on the all automatic setting.
If I set the front of the camera to manual. but leave the top button on green, will it still be on automatic with the exception of my having to use the focus ring?

I don't do well reading the guide book, and would be most appreciative of any help, as my lens no longer seems to focus in automatic...it searches in and out forever and never gets there.
Last Edited by ggsupersport on 30/06/2012 - 16:08

fritzthedog

Link Posted 30/06/2012 - 23:46
Hi Georgia

If you move the switch to MF from AF on the camera - yes everything except focus will still be automatic.

The problem with your lens not focusing may be something very simple such as a bad electrical contact. Have you tried cleaning all of the pins on the camera mount on the bottom of the lens with an alcohol based cleaning fluid and done the same thing on the contacts on the lens connector ring on the front of the camera?

Sometimes these get stuck due to a build up of dust/ dirt and a simple cleaning can sort it out.

It is certainly worth trying.

Good Luck

Carl
No matter how many lenses I have owned - I have always needed just one more

ggsupersport

Link Posted 30/06/2012 - 23:50
Thank you Carl, I will try that and see if it helps.....

ggsupersport

Link Posted 01/07/2012 - 01:58
Well Carl, the cleaning didn't work. I don't feel good about sending it in for repair...in the meantime purchased a Tamron 18-200...but it doesn't seem to be quite as sharp as the Pentax. I read once where the Pentax 18-250 was basically a Tamron lens with a little upgrade...not sure if there is anything to that. Also found a site that compared the two lenses and there didn't seem to be much difference. Maybe some of it is in my head. I will try to learn to use the Pentax lens manually.

Do you have any further suggestions?

Thanks Much,

Georgia

johnriley

Link Posted 01/07/2012 - 08:47
If you can post a picture where the lens has had difficulty focusing we might get some clues from that, if, for example, the problem is the subject matter being difficult to lock onto.

Cleaning the contacts on lens mount and body mount and making sure the lens is seated with a firm click may help. Also making sure the AF switch is positively set to AF and not just slightly off.
Best regards, John

fritzthedog

Link Posted 01/07/2012 - 09:39
ggsupersport wrote:
Well Carl, the cleaning didn't work. I don't feel good about sending it in for repair...in the meantime purchased a Tamron 18-200...but it doesn't seem to be quite as sharp as the Pentax. I read once where the Pentax 18-250 was basically a Tamron lens with a little upgrade...not sure if there is anything to that. Also found a site that compared the two lenses and there didn't seem to be much difference. Maybe some of it is in my head. I will try to learn to use the Pentax lens manually.

Do you have any further suggestions?

Thanks Much,

Georgia

If you mean the Tamron 18-250 - yes it is basically the same lens as your Pentax and if I remember correctly - the main difference was the coating to the front element. I used to own the Pentax and Samsung versions and have to say that I could not tell them apart in terms off performance. Some people claimed that the Pentax coating was better than the others. This may or may not be true but what is true is that often you can find variances in performance of 2 copies of the same lens!

As the focus motor for this lens is in the camera (and working on your Tamron) I still think it is most likely to be a connection problem of some sort and the AF is not engaging properly (unless the lens has been dropped or badly knocked). Does it focus properly manually? Does it make any strange noises that may suggest something mechanical Do you have or know somebody who has another Pentax body you could try the lens on? Do you know anybody with the same lens that you could compare with?

Carl
I have never had a Pentax AF
No matter how many lenses I have owned - I have always needed just one more

milamber

Link Posted 01/07/2012 - 10:07
Hi Georgia

It could be the focus settings on the camera or, as John says, the type of subject you are trying to lock onto. Try it with a range of subjects at different distances and see if it works at all.

Whereabouts are you? I have a Pentax 18-250 you would be welcome to try to see if it is the camera or the lens, but not a K20.

It's worth getting the problem sorted. The 18-250mm is quite a sought after lens now that it's discontinued and, in my opinion anyway, a whole lot better than the Tamron 18-200.
Last Edited by milamber on 01/07/2012 - 10:09

fritzthedog

Link Posted 01/07/2012 - 10:18
John and Chris may be correct re subject and it is worth checking. Given the length of time you have owned the camera and lens - I had concluded that this is a recent problem and not limited to only happening in certain situations. As your Tamron is focusing correctly - it is unlikely to be a focus setting problem but again worth checking - there is a dial on the back of the K20 - is it set to auto, sel or centre? Set it to centre and try focusing on an object in the centre of the frame.

Carl
No matter how many lenses I have owned - I have always needed just one more

ggsupersport

Link Posted 01/07/2012 - 16:09
I tried the Pentax 18-250 on a Pentax K10, and it behaves the same.
Is it possible to add photos to this forum?

johnriley

Link Posted 01/07/2012 - 16:17
Quote:
Is it possible to add photos to this forum?

Yes, instructions are in the Your Photos section of the forum.
Best regards, John

ggsupersport

Link Posted 01/07/2012 - 16:54
I see how to add to gallery...but not to forum alone so you can view my "out of focus" shot...

johnriley

Link Posted 01/07/2012 - 16:57

ggsupersport

Link Posted 01/07/2012 - 18:22
John,
I do not want to post a photo to a website if it is a dud. I thought maybe I could put it in the forum, so only those wanting to help me with my problem could see it.

bforbes

Link Posted 01/07/2012 - 20:28
I think if you use photobucket you could open a Private album, not for public viewing, but link the images you want to your post.
Barrie
Too Old To Die Young

http://www.pentaxphotogallery.com/artists/barrieforbes
https://www.flickr.com/photos/189482630@N03/

Gwyn

Link Posted 01/07/2012 - 20:59
Georgia you can always take the photo down again from Photobucket once people here have been able to see it and comment on it.
If you add a note that it is there because you are worried about the lens no-one will think you are a bad photographer, always assuming someone other than us finds your Photobucket account and views it.
Add a Comment
You must be registered or logged-in to comment.