Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
01-08-2020, 11:41 AM   #16
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 35,551
QuoteOriginally posted by Tas Quote
After fitting the screen in both cameras the focus test identified I had to swap the shims. Again, very simple to do, but again, be cognisant of managing dust. Once I swapped to one of the issued nylon shims the focus was spot on in both instances (K5 & K-1).
That is good to know. Apparently they have changed their choice of materials since my March 2014 purchase. The included shims at that time were very flexible and difficult to position in the shim holder, they kept falling out. Thickness was close, but not spot on, though I was able to get correct focus using factory shims.

Focusingscreen makes a good product and despite my problems, I still recommend them as an option for aftermarket screens with the caution that they don't refund opened goods and post-sale support may be a little thin. The other option being to do the cut-down yourself from readily-available Canon or Nikon screens and figure out a way to craft your own shims.

Steve

01-08-2020, 01:30 PM - 2 Likes   #17
Site Supporter
Site Supporter




Join Date: Dec 2015
Photos: Gallery | Albums
Posts: 776
QuoteOriginally posted by barondla Quote
Have all the DSLR manufacturers crippled their viewfinder focusing?
For the factory-installed focusing screens they did, as far as I have read / seen / tried. The difference is, that other manufacturers offer manual-focus optimized options, whereas Pentax's ML/MF/MI/ME-60 (for APS-C Kameras) just differ in the lines, despite their claims in the catalog: "These interchangeable focusing screens provide easy detection of the in-focus area, and allow for extra fine focus adjustment in manual-focus operation." Obviously, Pentax does talk about focus screens and using them for manual focus.

Just did an informal experiment: With the Pentax standard focusing screen, my KP is A LOT brighter than my EF-S equipped K-5 when using the DFA 50mm Macro, without significant advantages in determining focus, maybe a tad narrower range but not a night-and-day difference (which it is for brightness). Using the FA77, the viewfinder brightness has somewhat caught up, but it still muted. The DoF of the viewfinder image is a little narrower on the EF-S-Type screen. If I had to quantify, it's maybe about 1.5cm (+/- 0.7cm, EF-S) instead of 2cm (+/- 1cm, Pentax) range at an 80cm ruler as target, at a ~30 degree angle, outside of which things blur visibly for me. For the FA 50mm 1.4 (my only f/1.4 lens), things improve in favor of the EF-S again. Only slight difference in brightness left, and a lot narrower DoF in the viewfinder than on the Pentax screen, especially with a lot "steeper' fall-off and overall more pronounced blur in the unsharp regions.

The DFA 100mm WR and FA 31mm behave similar to the above - very little difference other than a darker viewfinder for the 100mm f/2.8, and some improvement for the 31mm LTD, still at the price of a somewhat darker viewfinder. The EF-S created a moireť out of the 1mm marks on the ruler when vieed at 60cm distance, so things where somewhat difficult to judge.

As a third data point, the brightness of the screen in my Pentax program-A is in between the other two, and it looks fairly grainy outside the focusing aids. It has a microprism ring and a horizontal split image circle. The microprism ring showed the slightest deviations of the focusing point on my relatively contrasty and regular target. I remember this is different with less contrasty subjects. For both the Fa50mm/1.4 and the DFA50mm/2.8 macro, it definitely gave the most distinct indication of focus.



So if manual focus with really fast lenses is your concern, the EF-S definitely is much more usable. Around f/2.8, I don't see an improvement anymore and would recommend one of the other types. Note that at around f/5.6, those focusing aids tend to go (partially) dark unless your pupil is in the dead center. Even then, the microprism is almost unusable, the split screen still works well though.
01-08-2020, 01:44 PM   #18
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: midwest, United States
Photos: Gallery | Albums
Posts: 4,276
QuoteOriginally posted by JensE Quote
For the factory-installed focusing screens they did, as far as I have read / seen / tried. The difference is, that other manufacturers offer manual-focus optimized options, whereas Pentax's ML/MF/MI/ME-60 (for APS-C Kameras) just differ in the lines, despite their claims in the catalog: "These interchangeable focusing screens provide easy detection of the in-focus area, and allow for extra fine focus adjustment in manual-focus operation." Obviously, Pentax does talk about focus screens and using them for manual focus.

Just did an informal experiment: With the Pentax standard focusing screen, my KP is A LOT brighter than my EF-S equipped K-5 when using the DFA 50mm Macro, without significant advantages in determining focus, maybe a tad narrower range but not a night-and-day difference (which it is for brightness). Using the FA77, the viewfinder brightness has somewhat caught up, but it still muted. The DoF of the viewfinder image is a little narrower on the EF-S-Type screen. If I had to quantify, it's maybe about 1.5cm (+/- 0.7cm, EF-S) instead of 2cm (+/- 1cm, Pentax) range at an 80cm ruler as target, at a ~30 degree angle, outside of which things blur visibly for me. For the FA 50mm 1.4 (my only f/1.4 lens), things improve in favor of the EF-S again. Only slight difference in brightness left, and a lot narrower DoF in the viewfinder than on the Pentax screen, especially with a lot "steeper' fall-off and overall more pronounced blur in the unsharp regions.

The DFA 100mm WR and FA 31mm behave similar to the above - very little difference other than a darker viewfinder for the 100mm f/2.8, and some improvement for the 31mm LTD, still at the price of a somewhat darker viewfinder. The EF-S created a moireť out of the 1mm marks on the ruler when vieed at 60cm distance, so things where somewhat difficult to judge.

As a third data point, the brightness of the screen in my Pentax program-A is in between the other two, and it looks fairly grainy outside the focusing aids. It has a microprism ring and a horizontal split image circle. The microprism ring showed the slightest deviations of the focusing point on my relatively contrasty and regular target. I remember this is different with less contrasty subjects. For both the Fa50mm/1.4 and the DFA50mm/2.8 macro, it definitely gave the most distinct indication of focus.



So if manual focus with really fast lenses is your concern, the EF-S definitely is much more usable. Around f/2.8, I don't see an improvement anymore and would recommend one of the other types. Note that at around f/5.6, those focusing aids tend to go (partially) dark unless your pupil is in the dead center. Even then, the microprism is almost unusable, the split screen still works well though.
Thanks for the real world testing and reporting of these results. I will have to reconsider changing the focusing screen in the K-1. Remember having very specialized focusing screens for my Olympus OM system. Some of the macro screens wouldn't even work for normal lenses and photography.

Thanks,
barondla
01-08-2020, 04:47 PM - 2 Likes   #19
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Location: Blue Mountains, NSW, Australia
Posts: 4,750
Original Poster
I think I'll put in an order in for a Canon S Type (link in my first post), this just feels like something I have to tick off the list as a 'been there tried that' kinda thing.

01-09-2020, 01:05 PM   #20
Otis Memorial Pentaxian
Loyal Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 35,551
QuoteOriginally posted by BruceBanner Quote
I think I'll put in an order in for a Canon S Type (link in my first post), this just feels like something I have to tick off the list as a 'been there tried that' kinda thing.
Cool! And the next time the subject comes up, you can add your experience to help the next person.


Steve
01-09-2020, 01:15 PM   #21
Site Supporter
Site Supporter
BruceBanner's Avatar

Join Date: Dec 2015
Location: Blue Mountains, NSW, Australia
Posts: 4,750
Original Poster
QuoteOriginally posted by stevebrot Quote
Cool! And the next time the subject comes up, you can add your experience to help the next person.


Steve
I will try and document all my failings in detail
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!
af, change of focus, character, dslr, focus, focus screen thread, full frame, full-frame, k-1, k1, lv, pentax k-1, screen, shots, swap
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Yet another advice thread :-) kevinWE Pentax SLR Lens Discussion 22 08-17-2019 09:42 PM
Super-A focus screen - what bodies have similar focus screen? radkoo Pentax Film SLR Discussion 11 08-14-2019 01:35 AM
Yet another focus screen question... jerry7171 Pentax DSLR Discussion 2 02-19-2016 12:44 PM
Yet another "Upgrading to a K-5 from a K-x" thread! BirdDude007 Pentax K-5 8 03-14-2012 01:29 AM
yet another focus screen question slow2focus Pentax Camera and Field Accessories 8 01-26-2010 09:07 PM



All times are GMT -7. The time now is 05:48 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