Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-12-2012, 03:33 AM   #1
New Member




Join Date: Jul 2012
Posts: 4
can i use 1.7x converter use with 16-45 f4

I own a Pentax K5 and the smc da 16-45 f4 pentax lens but find the lens a little to short for everyday use. Would any 1.4x (or 1.7x assuming I can find one) work with this lens


Last edited by mike lloyd; 07-12-2012 at 01:13 PM. Reason: corrected camera name
07-12-2012, 03:51 AM   #2
Inactive Account




Join Date: Sep 2011
Location: Melbourne
Photos: Gallery | Albums
Posts: 307
Why would you use a Teleconverter on a short lens (unless you were looking for a desired effect, like macro) just to get a little more reach.
Your f4 would reduce to about an f8 (other will correct me if I'm wrong) making it harder to shoot in low light.
why not consider getting a longer lens and still have a decent (if not better) aperture.
07-12-2012, 03:53 AM   #3
Site Supporter
Site Supporter




Join Date: Mar 2007
Location: Christchurch, New Zealand
Photos: Gallery
Posts: 492
Yes. But. You would loose 1 to 1.5 stops of light. So the lens would now be a 22mm to 63mm f5.6 or a 30mm to 76mm f6.5. Which is getting pretty dark.

You'd be better off getting a 28-80 f4 lens.

Additionally the 16-45 DA lens should darken inthe corners on a full frane camera.

Regards

Chris
07-12-2012, 04:16 AM   #4
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
Yes, but assuming the TC is AF capable, you will be at the limit of reliable AF. As others have noted, why would you do this.

07-12-2012, 04:28 AM   #5
Veteran Member




Join Date: Feb 2012
Location: Fredericton, New Brunswick
Photos: Gallery
Posts: 631
Pick up a cheap 28-80, 3.5-4.5. Non-SMC versions are still quite nice, and very cheap.
07-12-2012, 06:50 AM   #6
Veteran Member




Join Date: Feb 2011
Posts: 4,893
QuoteOriginally posted by mike lloyd Quote
I own a Pentax P5 and the smc da 16-45 f4 pentax lens but find the lens a little to short for everyday use. Would any 1.4x (or 1.7x assuming I can find one) work with this lens
As other are saying, this is to be avoided, even if the T/C fits on the lens (which definitely could be a problem depending on T/C - glass could hit glass). For the cost of a decent T/C you could pick up an el-cheapo lens which would be faster and have better IQ.
07-12-2012, 09:15 AM   #7
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,821
If you meant the P5 (which is a manual focus film era camera) then I agree with the above advice. The DA 16-45 is designed for digital and you are just better off getting a cheap 'A' series kit lens. You will have better range and less bother.

If you actually meant the K-5, then the 16-45 makes more sense for use with your camera. But, the above advice is still valid. Tele-converters are best used with fast, long prime lenses, generally over 200mm. It is usually cheaper to buy a longer lens than to buy a good TC to add to a short length zoom. If you like a longer range and do not mind losing the short end look at the FA 28-70 f/4 or any of the 28-80 kit lenses. The F 35-70 is also an excellent very sharp lens. There is also the FA 28-90 which is not as good for IQ but has a nice range. There are tons of film era zooms of that focal length range on the market that sell for not much money.

If you want longer range but want to keep the wide end then take a look at the newer DA18-135.
07-12-2012, 10:01 AM   #8
New Member




Join Date: Jul 2012
Posts: 4
Original Poster
thanks for feedback

thanks to everyone that's given feedback .... I'm fairly new to this game and have learnt a lot from the feedback ... and yes I got it wrong ... my camera is the DLSR P5 and I guess I should be looking at lenses like the Pentax SMC DA 17-70mm F4 AL IF SDM which has good reviews and more importantly for me it's very sharp.

07-12-2012, 10:28 AM   #9
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,821
QuoteOriginally posted by mike lloyd Quote
yes I got it wrong ... my camera is the DLSR P5
Mike, did you get it wrong again? P5 or K-5? Not trying to be picky but the advice you get is going to be based on what equipment we think you have. And there is a huge difference between a manual focus, full frame, film era camera (P5) and an auto-focus, APS-C sensor, digital camera (K-5). I just hate to give people advice and find out I steered them wrong because I assumed they had a different piece of kit than they really do.

And if you think camera names are confusing, well when you start talking lens you need to specify every detail because there have been so many different versions with only a slight change in the name.
07-12-2012, 01:11 PM   #10
New Member




Join Date: Jul 2012
Posts: 4
Original Poster
Apologies - K5 not P5

thanks again Jatrax for taking the time to correct me ; it is the Pentax K-5 DSLR that I've got (it obviously a bad day but at least I got the lenses right!)
07-12-2012, 03:10 PM   #11
Site Supporter
Site Supporter
jatrax's Avatar

Join Date: May 2010
Location: Oregon
Photos: Gallery | Albums
Posts: 10,821
QuoteOriginally posted by mike lloyd Quote
Pentax K-5 DSLR that I've got
No problem Mike, and I hope I did not sound too picky. The problem is, Pentax has a very long history as camera companies go, back to the mid 50's with the m42 line. And most if not all of that equipment is still in play. I have a 135mm Takumar lens made in 1957 that works just fine on my K-5. So, it's easy to assume someone is talking about a completely different piece of kit.

The DA 17-70 is worth a look and so is the DA 18-135. In case you did not know there is a complete database, and reviews, of all Pentax lenses located here.
07-12-2012, 04:33 PM   #12
Veteran Member




Join Date: Feb 2011
Posts: 4,893
I'd recommend the 17-70, fwiw.
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!
1.7x, f4, k-mount, lens, pentax, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Sigma 1.4x converter vs Sigma APO 1.4x converter slackercruster Pentax SLR Lens Discussion 3 04-03-2012 07:50 AM
Help with 2X converter matesa Pentax Medium Format 4 12-18-2011 12:45 PM
2x Converter paul cliff Pentax SLR Lens Discussion 4 02-15-2011 01:23 PM
Will the converter fit? chucuyuco Pentax SLR Lens Discussion 16 09-08-2010 11:24 AM



All times are GMT -7. The time now is 07:18 AM. | See also: NikonForums.com, CanonForums.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