Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-13-2016, 01:39 PM   #31
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 15,193
QuoteOriginally posted by Gutta Perka Quote
The baffle is very strong metal - also described by Pentax themselves describing their constructions.

Foam is on it!

That's it!

Don't like this thread - go on enjoy the others.
Don't try putting words in my mouth. I never said I didn't like the thread.

You dremmeled something, unclear to me why or what. Some people expressed the view that the foam was all that needed to be removed. The thread is good in that there is discussion, but very hard to follow. You mention the part is strong, but is the strength needed? Does it carry any load? Is there any reason it couldn't be replaced with a cardboard or phenolic tube?

05-13-2016, 02:10 PM   #32
Senior Member




Join Date: Dec 2012
Posts: 109
QuoteOriginally posted by UncleVanya Quote
Don't try putting words in my mouth. I never said I didn't like the thread.

You dremmeled something, unclear to me why or what. Some people expressed the view that the foam was all that needed to be removed. The thread is good in that there is discussion, but very hard to follow. You mention the part is strong, but is the strength needed? Does it carry any load? Is there any reason it couldn't be replaced with a cardboard or phenolic tube?
Dear one .... this is not for the the fainthearted.

We are talking and revising Pentax Star * optics!

Buy yourself something else!
05-13-2016, 04:48 PM - 1 Like   #33
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 15,193
QuoteOriginally posted by Gutta Perka Quote
Dear one .... this is not for the the fainthearted.

We are talking and revising Pentax Star * optics!

Buy yourself something else!
Dear sir. You are an unhelpful bore. You are now in my ignore list. Bliss.

---------- Post added 05-13-16 at 08:39 PM ----------

QuoteOriginally posted by npc Quote
I guess everyone has seen the samples where DA* 60-250 "almost" covers FF with some dark corners.

But Pentax has a patent for a FF 60-250 lens so I thought maybe it is just the baffle at the back causing the dark corners.

So I finally got some time and disassembled mine to remove the baffle - and tested it on sony a7r. The results are pretty good! Dark corners were gone at all focal lengths.
I've noticed some light vingeting on some focal lengths wide open but no more than what I expect from any lens.
Resolution outside the APS-C zone is good as well, except maybe at 250 (but generally mine is somewhat worse at 250 than for example at 200 even on aps-c).

It is a pretty easy mod to do - just unscrew the mount (and make sure you dont loose those spring-loaded contact pins). The baffle is just a black tube that is glued (!?) with some spots of white glue to the back of the mount.
(I find it litte weird that the baffle is just glued that way - almost like it was not part of the original design and they just figured a way do add it later.)

Apparently the glue is not strong so you should be able to easily pry it out of the mount and re-assemble the lens without it. - And you'll have your FF lens ready.

Mod is fully reversible, as you can just glue the baffle back in its place. I guess it's purpose is to reduce internal reflections but I did notice any problems in that regard while testing.
I tested without the hood but I guess it should be fine at least in the 90-250 range.

Anyway, it looks like the FF camera is delayed again but I thought someone might find this information useful.
Since you took yours all the way off I assume you retained it. Since removing it have you seen any ill effects from removing it? Any situations where it is less sharp or you see less contrast when you have the lens wide open?
05-13-2016, 07:19 PM   #34
npc
Veteran Member




Join Date: Apr 2013
Posts: 313
Original Poster
QuoteOriginally posted by UncleVanya Quote
Dear sir. You are an unhelpful bore. You are now in my ignore list. Bliss.

---------- Post added 05-13-16 at 08:39 PM ----------



Since you took yours all the way off I assume you retained it. Since removing it have you seen any ill effects from removing it? Any situations where it is less sharp or you see less contrast when you have the lens wide open?
No, I have not seen any bad effects so far - I kept using it on K5IIs meanwhile. Did not use it much on FF since it was kind of front heavy on A7R and I don't really like the adapters for DA lenses.
In theory it can reduce the contrast in some situations due to reflections from the sensor (with felt on the outside, etc I assume that was its main purpose on APS-C since the rear element is anyway oversized for APS-C) but I have not really noticed any bad side effects . However, I've tried to replace it with some black tube I've made from cardboard initially and that made it noticably worse - material was not suitable for this I guess.

I will be off the grid ths weekend but I'll try to post some FF raws on Monday

05-13-2016, 08:23 PM   #35
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 15,193
QuoteOriginally posted by npc Quote
No, I have not seen any bad effects so far - I kept using it on K5IIs meanwhile. Did not use it much on FF since it was kind of front heavy on A7R and I don't really like the adapters for DA lenses.
In theory it can reduce the contrast in some situations due to reflections from the sensor (with felt on the outside, etc I assume that was its main purpose on APS-C since the rear element is anyway oversized for APS-C) but I have not really noticed any bad side effects . However, I've tried to replace it with some black tube I've made from cardboard initially and that made it noticably worse - material was not suitable for this I guess.

I will be off the grid ths weekend but I'll try to post some FF raws on Monday
That's helpful info. Thanks. Any idea what was the problem with the alternate tube exactly? Shiny? Not the right size exactly?
05-14-2016, 04:20 AM   #36
Senior Member




Join Date: Dec 2012
Posts: 109
QuoteOriginally posted by npc Quote
No, I have not seen any bad effects so far - I kept using it on K5IIs meanwhile. Did not use it much on FF since it was kind of front heavy on A7R and I don't really like the adapters for DA lenses.
In theory it can reduce the contrast in some situations due to reflections from the sensor (with felt on the outside, etc I assume that was its main purpose on APS-C since the rear element is anyway oversized for APS-C) but I have not really noticed any bad side effects . However, I've tried to replace it with some black tube I've made from cardboard initially and that made it noticably worse - material was not suitable for this I guess.

I will be off the grid ths weekend but I'll try to post some FF raws on Monday

Not needed - that lens shade seems to be for FF as well!

Thanks for inspiring me!!!!!!

/Gutta Perka
05-14-2016, 08:10 AM   #37
New Member




Join Date: Jul 2015
Posts: 2
QuoteOriginally posted by UncleVanya Quote
You dremmeled something, unclear to me why or what. Some people expressed the view that the foam was all that needed to be removed. The thread is good in that there is discussion, but very hard to follow. You mention the part is strong, but is the strength needed? Does it carry any load? Is there any reason it couldn't be replaced with a cardboard or phenolic tube?
I agree. It's not clear what has actually been done. Removing parts of a lens usually impacts optical quality in some ways...
05-14-2016, 10:02 AM   #38
Senior Member
PiotrKrochmal's Avatar

Join Date: May 2010
Location: Poland -> Kraków
Posts: 199
DA*60-250 post LR full versions on my page




05-14-2016, 12:50 PM   #39
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 15,193
QuoteOriginally posted by PiotrKrochmal Quote
DA*60-250 post LR full versions on my page

Those look nice.
05-14-2016, 03:27 PM - 1 Like   #40
Veteran Member
MJSfoto1956's Avatar

Join Date: Dec 2013
Location: Boston
Posts: 1,289
I was going to be happy with a 1:1 or 4:5 crop with the DA* 60-250mm -- seems we might be able to get a bit more after all...
All-in-all, this is great news.

Michael
05-14-2016, 09:17 PM   #41
Emperor and Senpai
Loyal Site Supporter
VoiceOfReason's Avatar

Join Date: Jun 2010
Location: Nashville, IN
Photos: Albums
Posts: 5,938
It definitely vignettes, even with the lens hood off. Took this today.

---------- Post added 05-14-16 at 10:18 PM ----------

Ohh, and the reflections and lower contrast areas were because I took it through a window that I really need to clean.
Attached Images
View Picture EXIF
PENTAX K-1  Photo 
05-14-2016, 11:16 PM   #42
Loyal Site Supporter
Loyal Site Supporter
UncleVanya's Avatar

Join Date: Jul 2014
Photos: Gallery | Albums
Posts: 15,193
QuoteOriginally posted by VoiceOfReason Quote
It definitely vignettes, even with the lens hood off. Took this today.

---------- Post added 05-14-16 at 10:18 PM ----------

Ohh, and the reflections and lower contrast areas were because I took it through a window that I really need to clean.
This is with or without the mod?
05-15-2016, 04:04 AM   #43
Pentaxian




Join Date: Nov 2013
Posts: 4,857
This is interresting to know, but I would say mostly for existing owners. The vigneting is quite present.

The actual price is too high to justify it against say a tamron 70-200 and the 250mm is only obtained at infinite...
05-15-2016, 05:47 AM - 1 Like   #44
Emperor and Senpai
Loyal Site Supporter
VoiceOfReason's Avatar

Join Date: Jun 2010
Location: Nashville, IN
Photos: Albums
Posts: 5,938
QuoteOriginally posted by UncleVanya Quote
This is with or without the mod?
Without
05-15-2016, 11:47 AM   #45
Senior Member
PiotrKrochmal's Avatar

Join Date: May 2010
Location: Poland -> Kraków
Posts: 199
QuoteOriginally posted by Nicolas06 Quote
This is interresting to know, but I would say mostly for existing owners. The vigneting is quite present.

The actual price is too high to justify it against say a tamron 70-200 and the 250mm is only obtained at infinite...
Yeap price now is ridiculous I bought mine in 2010 and pay about 970$. That was fair
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!
aps-c, contact, control, corners, da*, da* 60-250 mod, ff, glue, jis, k-mount, lengths, lens, mine, mod, monitor, mount, paint, pentax, pentax lens, ph, price, screw, slr lens, spray, springs, tube, vignette
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
AS plate for the DA*60-250/300 lens foot interested_observer Pentax Camera and Field Accessories 21 03-04-2018 03:56 PM
DA* 60-250 owners: How do you carry your 60-250 at the ready? apisto Pentax SLR Lens Discussion 25 12-30-2017 01:49 PM
For Sale - Sold: Pentax DA* 60-250, RRS L bracket for K-5 prices reduced again djc737 Sold Items 7 06-27-2015 05:08 AM
Backpack for DA*60-250 and 16-50 gastch Pentax Camera and Field Accessories 18 01-23-2015 11:46 AM
DA*60-250/4 - FF, sharp and fast. ogl Pentax SLR Lens Discussion 19 11-01-2008 04:11 PM



All times are GMT -7. The time now is 12:03 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