Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-04-2015, 07:29 PM   #1
New Member




Join Date: Dec 2014
Posts: 17
A style 100 ~ 300 lens on a K-200

I have this older lens on My camera and it won't focus sharply when photographing the moon ,or other distant subjects. Is this to be expected or could I be doing something wrong? Thanks for any and all help!

04-04-2015, 07:42 PM   #2
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,288
Not much info to go on.
I assume "A style" means a manual lens with 'A' contacts? So manual focus right? Most lenses will focus past infinity so if you are just twisting it to the stop that is not going to be in focus necessarily.

If that does not help, post more info. Which lens exactly? How are you focusing? Have you tested it in good light with a focus target?
04-04-2015, 07:47 PM   #3
New Member




Join Date: Dec 2014
Posts: 17
Original Poster
Focus

Pentax FA lens And it doesn't seem to help if I manually focus it short of infinity. I know it's a cheap piece but I was expecting better .Auto focus does not seem to work real well on Moon photos.
04-04-2015, 07:51 PM   #4
Site Supporter
jimr-pdx's Avatar

Join Date: May 2010
Location: 1hr north of PDX
Photos: Gallery | Albums
Posts: 3,480
Do you have a camera that can 'do' AF adjustments? Many more recent ones can do that for individual lenses, though with some zooms the precise focus may not be the same throughout the range. It might help though.. let us know which body you have and we'll go from there. Of course, if even manual focus cannot reach infinity we might not be able to do much.

04-04-2015, 08:01 PM   #5
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,288
QuoteOriginally posted by lowbudgetphoto Quote
Pentax FA lens And it doesn't seem to help if I manually focus it short of infinity. I know it's a cheap piece but I was expecting better .Auto focus does not seem to work real well on Moon photos.
There are a couple 100-300's in the FA series and no they are not limited glass but they should not be that bad either. One is supposedly better than the other which do you have?

Post a picture with the EXIF intact that might help. Moon shots are not the easiest, have you practiced with it under less difficult conditions? For the moon what settings are you using? Tripod?

I would do some controlled tests on a tripod with good light and a good sharp target. That will tell you if it is the lens or your technique or settings.
04-04-2015, 08:01 PM   #6
New Member




Join Date: Dec 2014
Posts: 17
Original Poster
Focus

I use this lens on a K-200 and a K - 2000 with similar results. When I use My DAL 50 ~ 200wr it gives a sharp image.
04-04-2015, 08:42 PM   #7
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 40,959
QuoteOriginally posted by lowbudgetphoto Quote
Pentax FA lens And it doesn't seem to help if I manually focus it short of infinity. I know it's a cheap piece but I was expecting better .Auto focus does not seem to work real well on Moon photos.
Infinity as marked on the lens isn't always true infinity. You need to look through the viewfinder to verify that the image is sharp, and make adjustments accordingly. Also, make sure your tripod is stable.

Fine-tuning the focus on distant subjects is tough without live view, which the K200D unfortunately lacks. All the newer Pentax DSLRs have it, though

Adam
PentaxForums.com Webmaster (Site Usage Guide | Site Help | My Photography)



PentaxForums.com's high server and development costs are user-supported. You can help cover those costs by donating. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:

04-05-2015, 03:43 AM - 1 Like   #8
Pentaxian
calsan's Avatar

Join Date: Nov 2008
Location: Perth, Australia
Photos: Gallery
Posts: 1,367
What's your exposure time? The moon is actually moving very quickly through your field of view at 300mm. Less than 1/180 will give some blurring. Start in M mode with 1/250 second, f/8, ISO 100. Will have to vary exposure a bit depending on the phase. Adjust using aperture first, then ISO, but leave shutter speed high.

04-05-2015, 04:33 PM   #9
New Member




Join Date: Dec 2014
Posts: 17
Original Poster
I will do some more trial and error My shutter speed may be too slow.
05-02-2015, 09:12 PM   #10
New Member




Join Date: Dec 2014
Posts: 17
Original Poster
Ok ! After I went back thru My old moon photos I found they were taken with a shutter speed of 1/90 thru8 1/250 sec. I have been trying to shoot at 1/1000 of faster . It makes no sense to me ,but I went out tonight and used some of the earlier settings and got my sharpness back. Thanks to all who provided suggestion and "food for thought" .
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!
camera, focus, lens, pentax help, photography, troubleshooting
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Teleconverter for Tokina A-FX 100/300 F4 Lens Driline Pentax SLR Lens Discussion 5 04-16-2014 03:45 PM
70-200 2.8 on a k-3 deadprez Pentax K-3 11 01-05-2014 10:28 AM
For Sale - Sold: Pentax FA 100-300, FA 70-200, A 50mm; Sigma EX 28-70; Helios 58mm, M42->K adapter stillnk Sold Items 4 05-20-2012 11:15 AM
Macros: DFA 100 WR, A 100 2.8, A* 200, Sigma 180, Sigma 150 atlnq9 Pentax SLR Lens Discussion 20 10-11-2011 12:26 PM
Does anyone know if a Vivitar Series 1 100-500mm lens will fit on a Pentax K-m? cobra k-m Pentax SLR Lens Discussion 9 04-22-2010 07:08 AM



All times are GMT -7. The time now is 12:00 PM. | See also: NikonForums.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