Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-21-2019, 02:48 PM   #1
Junior Member




Join Date: Nov 2017
Posts: 48
K1 with 28-105 D FA lens and 1.4x Teleconverter

Good day,

Pentax k1 user here. I'm going on a 10 day hiking trip in Iceland next year and so weight is an issue in terms of the lenses I carry with the K1. I will take the 20-35 and the 28-105 will be my default lens on the camera. I also would ideally benefit from a mild telephoto option - preferably in the 200mm range (I have a DA* 300 but weight makes it prohibitive to carry on this trip).

If I use the 28-105 in Crop mode that gets me past 150mm, and then if I use the pentax 1.4x teleconverter with it that improves the reach (in theory) even further. My question is - is using the TC with the the 28-105, whether in crop or FF mode, worth it? I apologise if I've missed it but haven't seen much discussion of the performance of the TC with this lens - but if I could get away with it, it would be a handy option. Pentax's list says the 28-105 is compatible with the TC, but real world performance / quality is what I'm interested in.

Thank you

12-21-2019, 03:16 PM   #2
Senior Member




Join Date: Jun 2017
Posts: 232
I'm afraid I can't help you with the TC performance, but I do have a question/observation. I don't have a K1 so I'm curious why the crop mode would be used on a full frame lens. I would think you'd be better to take the photo full frame, then crop it later in post processing. That would give the most flexibility to crop it how you want. Perhaps I'm missing something?
As far as the TC goes, it will be interesting to hear if the TC gives better results than just cropping.
12-21-2019, 03:23 PM - 1 Like   #3
Site Supporter
Site Supporter
JensE's Avatar

Join Date: Dec 2015
Location: Leipzig
Photos: Gallery | Albums
Posts: 1,942
QuoteOriginally posted by Qman Quote
I'm afraid I can't help you with the TC performance, but I do have a question/observation. I don't have a K1 so I'm curious why the crop mode would be used on a full frame lens. I would think you'd be better to take the photo full frame, then crop it later in post processing. That would give the most flexibility to crop it how you want. Perhaps I'm missing something?
As far as the TC goes, it will be interesting to hear if the TC gives better results than just cropping.
Smaller files, less battery use (especially for "expensive" operations/filters), faster frame rates. If you can frame in crop according to your desired result and post-process only on an as-needed basis, you may be able to get your final JPG this way.
12-21-2019, 03:29 PM - 1 Like   #4
Junior Member




Join Date: Nov 2017
Posts: 48
Original Poster
QuoteOriginally posted by Qman Quote
I'm afraid I can't help you with the TC performance, but I do have a question/observation. I don't have a K1 so I'm curious why the crop mode would be used on a full frame lens. I would think you'd be better to take the photo full frame, then crop it later in post processing. That would give the most flexibility to crop it how you want. Perhaps I'm missing something?
As far as the TC goes, it will be interesting to hear if the TC gives better results than just cropping.

If I use the lens in crop mode, AND the TC performs decently on it without massive vignetting, it gives me an additional 1.4x magnification factor which is >200mm. Just exploring it as an option.

12-21-2019, 04:35 PM   #5
Pentaxian




Join Date: Jan 2017
Photos: Gallery
Posts: 462
You should be able to do everything with your lenses without teleconverter. Also, I'm not sure it's advisable to put tc on a slow zoom lens. People put them on primes usually. Teleconverter of 1.4x will reduce lens aperture by 1 stop. What will happen with your autofocus if you put tc on your 28-105? Does it work? Try it if you have tc.
12-21-2019, 04:59 PM - 1 Like   #6
Loyal Site Supporter
Loyal Site Supporter




Join Date: May 2007
Location: Flagstaff, Arizona
Posts: 1,625
For the price of the Pentax TC, you could buy a 55-300 PLM. Since you seem to be content with crop mode, this might be a reasonable alternative. I suspect the overall picture quality would be better, or at least no worse, than the TC option.

Conversely, you might rethink whether you really need a telephoto option. Unless you are going after birds, I rather imagine that Iceland photos will be mostly landscape.
12-21-2019, 05:27 PM - 1 Like   #7
Junior Member




Join Date: Nov 2017
Posts: 48
Original Poster
Thanks for the replies.

I don't have the teleconverter, it's $600 odd dollars here so it's a fair investment.

I wouldn't say I'm 'content' with Crop mode - I barely use it. However I'm a fairly experienced landscaper and having spoken to my photography contacts in Iceland they reckon a mild telephoto would be handy. That said, if I have to just go with the 28-105mm and crop, so be it. I'm not a huge fan of the 55-300 on the K1 - it's a great lens on a crop sensor, but I noticed when I used it on the k1 images were not the quality I had hoped (too soft), so I sold mine. However I'm talking about the one that was around in circa 2015, I believe the one you are referring to is the newer version, I'll look into it and its performance on the K1. In a perfect world where money / weight was no object, the 60-250 would be the ideal solution


Last edited by ozarun55; 12-21-2019 at 05:36 PM.
12-21-2019, 05:45 PM   #8
Senior Member




Join Date: Jun 2017
Posts: 232
An alternative would be to pick up an FA 135 or F 135. Perhaps shorter than you want, but fast, sharp, and compact. The D FA 28-105 is only f5.6 at the long end, and the TC slows it down even more.
12-21-2019, 06:08 PM   #9
Junior Member




Join Date: Nov 2017
Posts: 48
Original Poster
The FA 135 could be an option depending on weight, I'll look into it. thank you. Not sure about its performance on the K1 either, but there must be someone who has tried that combo.
12-21-2019, 06:20 PM   #10
Pentaxian
KiloHotelphoto's Avatar

Join Date: Jan 2015
Location: Glen Mills, PA
Photos: Albums
Posts: 1,027
QuoteOriginally posted by Qman Quote
I'm afraid I can't help you with the TC performance, but I do have a question/observation. I don't have a K1 so I'm curious why the crop mode would be used on a full frame lens. I would think you'd be better to take the photo full frame, then crop it later in post processing. That would give the most flexibility to crop it how you want. Perhaps I'm missing something?
As far as the TC goes, it will be interesting to hear if the TC gives better results than just cropping.
The 1.4 tc is not full frame so it vignettes a lot so shooting in crop mode would be the way to go.
12-21-2019, 06:49 PM   #11
Senior Member




Join Date: Jun 2017
Posts: 232
QuoteOriginally posted by ozarun55 Quote
The FA 135 could be an option depending on weight, I'll look into it. thank you. Not sure about its performance on the K1 either, but there must be someone who has tried that combo.
Take a look at the user reviews. 375g
Several K1 users have reviewed it and they seem to really like it.
I have the F 135 (on APS-C) and the only complaint is purple fringing, but that's easy to fix.
12-21-2019, 10:18 PM   #12
Administrator
Site Webmaster
Adam's Avatar

Join Date: Sep 2006
Location: Arizona
Photos: Gallery | Albums
Posts: 51,584
Why not just get a DA 55-300mm and use it in crop mode?

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



PentaxForums.com server and development costs are user-supported. You can help cover these costs by donating or purchasing one of our Pentax eBooks. Or, buy your photo gear from our affiliates, Adorama, B&H Photo, KEH, or Topaz Labs, and get FREE Marketplace access - click here to see how! Trusted Pentax retailers:
12-21-2019, 10:51 PM   #13
Senior Member




Join Date: Jun 2017
Posts: 232
QuoteOriginally posted by Adam Quote
Why not just get a DA 55-300mm and use it in crop mode?
He said he's had one before and isn't a fan.
12-21-2019, 11:00 PM   #14
Loyal Site Supporter
Loyal Site Supporter
i_trax's Avatar

Join Date: Jan 2011
Location: Perth Western Australia
Photos: Gallery | Albums
Posts: 2,621
or try to find :
Tamron-F 1.4X Pz-AF MC4 Lens Reviews - Miscellaneous Lenses - Pentax Lens Review Database
I paid ~ AU$100 for mine and it works well with Pentax and Sigma ( incl HSM ) and it is FF.
I love it!
12-21-2019, 11:09 PM   #15
Junior Member




Join Date: Nov 2017
Posts: 48
Original Poster
Hi - thank you for the information regarding the Tamron TC I will look into that. It's a shame if pentax doesn't have a full frame TC and yet a third party does! Anyone else use that TC? I think the point that the 28-105 (especially at the long end) is already slow is fair enough, however this would still put the lens at f8 which is not too bad I would think.

The FA 135mm does I can see get good reviews so that's a possibility, although query whether 20mm extra reach is really worth it.

I really appreciate the replies everyone.
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!
crop, dslr, fa lens, full frame, full-frame, k-1, k1, lens, mode, pentax k-1, tc, teleconverter, weight
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
For Sale - Sold: Pentax FA*400, FA 28-105,100-300, DA*16-50, Tamron 28-300,18-200, K-7, *istDL & More Snapppy Sold Items 7 05-05-2019 06:44 PM
For Sale - Sold: Full frame AF and MF 'A' lenses - 17-35, 18-35, 24-70, 28, 28-105, 28-200, 135,70-210 scottDee Sold Items 9 02-13-2019 06:57 AM



All times are GMT -7. The time now is 01:56 PM. | 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