Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
04-27-2013, 07:03 AM   #1
Pentaxian
ChatMechant's Avatar

Join Date: Jun 2010
Location: Santa Cruz Mountains
Photos: Gallery
Posts: 754
DA vs DA*

I recently tested my 55-300 vs my newly acquired 50-135, in part because I was expecting a bit more from the da*. I was expecting to be at least as impressed as I was when I got my 16-50, which is actually better (sharper) than my 50-135. I haven't really been able to tell much diff in IQ between my 50-135 and my 55-300.
Anyway, here are some 100% crops taken with k-01 so there shouldn't be any FF/BF issues, right? 2sec timer.

da 50-135 @ 2.8


50-135 @ 5.6


55-300 @ 5.6


Again, sorry for the unscientific test chart. It's what was handy.

04-27-2013, 07:25 AM   #2
Veteran Member




Join Date: Feb 2011
Posts: 4,893
The 55-300 looks a hair better.

In reality the 50-135 should be a hair better than the 55-300. About 5-10% or so in the center... which is a "big" difference in theory but in reality is not very much.

You still could be having focus issues - one way to test is with tiny, tiny manual focus changes while taking the picture - and then take the best picture for each.

When you buy the 50-135 you're paying for speed and bokeh. If you want resolution, as you can see, there are other choices.
04-27-2013, 07:25 AM   #3
Pentaxian
Na Horuk's Avatar

Join Date: Feb 2012
Location: Slovenia, probably
Photos: Gallery | Albums
Posts: 10,863
I think the first one is a little bit out of focus. Can you try focusing on a tilted piece of text instead of one parallel to the sensor? If its at an angle, there is a better chance of the DoF being on text and thus also a better way to compare "sharpness". At f2.8 the DoF is so thin that it can touch on the text at the part where the camera is measuring focus, but then departs from the text further away. The DoF isn't flat and uniform
04-27-2013, 08:03 AM   #4
Pentaxian
ChatMechant's Avatar

Join Date: Jun 2010
Location: Santa Cruz Mountains
Photos: Gallery
Posts: 754
Original Poster
Yes I should really make sure it's not a focus thing. I did take three shots each and pick the sharpest, re-focusing each time. Also in the couple weeks I've had it, I haven't been able to get any sharpish shots wide open at 135 so I thought maybe that's just how the lens is.
So @ 2.8 should the 50-135 should be sharper than that? Or is that about right? At 50 and 2.8, It's about on par with the 16-50, which is very good.

04-27-2013, 09:01 AM   #5
Veteran Member




Join Date: Feb 2011
Posts: 4,893
QuoteOriginally posted by ChatMechant Quote
So @ 2.8 should the 50-135 should be sharper than that?
Yes. The 50-135 at 135 and F/2.8 should be about equal in resolution to the 55-300mm wide open at 135 (which should be about F/4.5 or F/5 or so?).

Depth of field at 135mm, F/2.8 and and 10 feet is about 2 inches... so it's pretty easy to have some error.
04-28-2013, 11:22 AM   #6
Pentaxian
ChatMechant's Avatar

Join Date: Jun 2010
Location: Santa Cruz Mountains
Photos: Gallery
Posts: 754
Original Poster
Okay. I thought by using the k-01 CDAF or K5 live view it would eliminate the FF/BF issue, but I spent a good amount of time calibrating focus on the k-5 and by golly, I now see why people go ga-ga over the 50-135. It is now prime-sharp right from 2.8. Achievement unlocked!
04-28-2013, 02:17 PM   #7
Veteran Member
tclausen's Avatar

Join Date: May 2012
Posts: 1,399
QuoteOriginally posted by ChatMechant Quote
Okay. I thought by using the k-01 CDAF or K5 live view it would eliminate the FF/BF issue, but I spent a good amount of time calibrating focus on the k-5 and by golly, I now see why people go ga-ga over the 50-135. It is now prime-sharp right from 2.8. Achievement unlocked!
Heh, loving that turn of phrase. The 50-135 at its sweet spot...definitely can rock with the best of them. I tend to use it most at 90mm+ and it's sweet
04-28-2013, 03:52 PM   #8
Pentaxian
twitch's Avatar

Join Date: Nov 2009
Posts: 4,571
QuoteOriginally posted by ChatMechant Quote
Okay. I thought by using the k-01 CDAF or K5 live view it would eliminate the FF/BF issue, but I spent a good amount of time calibrating focus on the k-5 and by golly, I now see why people go ga-ga over the 50-135. It is now prime-sharp right from 2.8. Achievement unlocked!
I was going to chime in about how much better the 50-135 should be, but I see you've solved it. Enjoy your new lens.

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!
da, da*, k-mount, pentax lens, slr lens, vs
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help with Lens Choice FA 43 vs. DA 35 2.8 vs. DA 40 LukeSkywalker Troubleshooting and Beginner Help 10 10-19-2012 06:29 PM
DA 50-200mm vs DA 55-300mm lens tiamaria2326 Troubleshooting and Beginner Help 23 02-11-2012 02:41 PM
For Sale - Sold: DA 15, DA 40, DA 70, DA 16-45, DA L 55-300, AF360 (Worldwide) yoshizuki Sold Items 23 10-22-2011 03:24 PM
DA 55-300 vs. the DA L Spudman Visitors' Center 4 08-14-2011 05:26 AM
DA 15mm vs DA 14mm vs Pentax 17-70 simonkit Pentax SLR Lens Discussion 2 09-02-2010 09:03 AM



All times are GMT -7. The time now is 06:16 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