Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-16-2011, 10:18 AM - 1 Like   #31
Site Supporter
hinman's Avatar

Join Date: Oct 2006
Location: Fremont, CA
Photos: Albums
Posts: 3,425
Oh, I want to share with you a picture taken with Pentax Auto 110 Pan Focus 18mm f/2.8 wide open in Sony NEX 5N



1/15 sec, f/2.8, iso 3200, 0 Ev, hand-held, jpg

Pentax Auto 110 Pan Focus 18mm f/2.8 on Sony NEX 5N

And there is no focus ring on this lens and it will focus from 6 ft to infinity.

Cheers,
Hin


Last edited by hinman; 12-16-2011 at 10:23 AM.
12-16-2011, 10:23 AM   #32
Site Supporter
hinman's Avatar

Join Date: Oct 2006
Location: Fremont, CA
Photos: Albums
Posts: 3,425
And here are some pictures using the Pentax Auto 70mm f/2.8 with a Soligor 1.7x TC. I can't yet recommend the Soligor TC as the mount has a lot of play and the TC makes the lens more lose in the mount rendering it difficult to focus as there is a lot of play when the TC is mounted.

One good thing in Soligor TC is that the TC has an aperture plate inside stopping down the lens to a bigger aperture as in f/5.6 to f/8.0 -- but I fall short in knowing the exact aperture that it goes to



















Pentax Auto 110 70mm f/2.8 with Soligor 1.7x TC

Center sharpness in general is quite good in the 70mm. And I do think the center sharpness in the 70 is better than the wider ones. My test pictures are not exactly good pictures to show as the bunny is moving around and I have a difficult time to focus on a LCD in afternoon sun. On the last picture, you can see that the corners may seem to be quite soft.

Cheers,
Hin
12-16-2011, 10:35 AM   #33
Pentaxian
Mistral75's Avatar

Join Date: Feb 2009
Location: Paris
Posts: 2,778
QuoteOriginally posted by hinman Quote
(...)

However, the Kipon adapter still doesn't have the diaphragm control and you will shooting wide open in f/2.8. Its construction in single piece may be easier to adapt a diaphragm. Unlike my other NEX adapter, the back is shallower and it may be easier to get a diaphragm to get close to the lens' rear. With the Pentax Q, I think the vignette problems in my NEX failed diaphragm experiment can be re-tried with better success rate. I will share more on my failed attempt when time allows

Here is the back picture of the Kipon adapter for the NEX E mount -- it should be similar to the Q. I will update later ...

(...)
Here is the back picture of the Kipon Pentax 110 --> Pentax Q adapter:

12-16-2011, 12:08 PM   #34
Pentaxian




Join Date: Oct 2006
Location: Chicago suburb, IL, USA
Posts: 1,535
QuoteOriginally posted by hinman Quote

One good thing in Soligor TC is that the TC has an aperture plate inside stopping down the lens to a bigger aperture as in f/5.6 to f/8.0 -- but I fall short in knowing the exact aperture that it goes to
Hi Hin,

Thanks for posting these samples and some details about the Soligor TC since there is scant information about it on the web, except that it's pretty rare.

Edit:-- okay-- rereading the post, Hin states that there's a plate that stops down the lens, not a diaphragm, so I've deleted the stuff I wrote assuming a diaphragm. . .

Scott


Last edited by snostorm; 12-16-2011 at 11:50 PM.
12-17-2011, 11:08 AM   #35
Senior Member
Mock's Avatar

Join Date: Feb 2009
Location: Edmonton
Photos: Gallery | Albums
Posts: 290
Kipon Adapter for PTX 110 P110 CINE/MOVIE to Pentax Q Camera, EXPRESS MAIL! | eBay

A little pricey, but they ship it Fedex/EMS, so at least it will come quickly. I don't understand why they would put "cine-movie" in the description...

Last edited by Mock; 12-17-2011 at 04:32 PM.
12-17-2011, 12:15 PM   #36
Site Supporter
hinman's Avatar

Join Date: Oct 2006
Location: Fremont, CA
Photos: Albums
Posts: 3,425
QuoteOriginally posted by snostorm Quote
Hi Hin,

Thanks for posting these samples and some details about the Soligor TC since there is scant information about it on the web, except that it's pretty rare.

Edit:-- okay-- rereading the post, Hin states that there's a plate that stops down the lens, not a diaphragm, so I've deleted the stuff I wrote assuming a diaphragm. . .

Scott
What you have provided are valuable information for people who may want to add an iris diaphragm to stop down the auto 110 lens. Yes, the TC does have a extra plate with smaller aperture opening. With a distance added to the lens rear because of the added TC length, I don't quite know the exact aperture that the extra plate actually fixed on the combination. You are much more well versed in your information and I wish you have not deleted the information.

And I do wish someone buying the adapter come back and have a picture views for the internal of the adapter to see if there is a chance to put in an iris diaphragm. I got two from jinfinace ebay store and the smaller one has a 20mm outside diameter and it fits the inner part that is closest to the lens rear. When I have time, I will share few pictures of my failed attempt in NEX conversion. Something similar can be done with better success on the Q as the lens, image circle from the Auto 110 lens should fit better for the sensor in Q and MFT sensors.

Cheers,
Hin
12-17-2011, 02:06 PM   #37
Pentaxian
Mistral75's Avatar

Join Date: Feb 2009
Location: Paris
Posts: 2,778
QuoteOriginally posted by Mock Quote
Ebay seller breguetcamera now has the Kipon adapter listed. US$95 with free expedited international shipping.

Kipon Adapter for PTX 110 P110 CINE/MOVIE to Pentax Q Camera, EXPRESS MAIL! | eBay

A little pricey, but they ship it Fedex/EMS, so at least it will come quickly. I don't understand why they would put "cine-movie" in the description...
Yes indeed...

QuoteOriginally posted by Mistral75 Quote
Now on eBay. Price is USD95, free shipping.

Kipon Adapter for PTX 110 P110 CINE/MOVIE to Pentax Q Camera, EXPRESS MAIL! | eBay

The Kipon Pentax 110 --> Q adapters for NEX and 4/3 bodies are also for sale as of today at the same price.
12-17-2011, 03:03 PM   #38
Pentaxian




Join Date: Oct 2006
Location: Chicago suburb, IL, USA
Posts: 1,535
QuoteOriginally posted by hinman Quote
With a distance added to the lens rear because of the added TC length, I don't quite know the exact aperture that the extra plate actually fixed on the combination.
Hi Hin,

I don't believe the distance added by the TC length would matter since the area of the light path is the only thing that's really relevant to relative aperture calculations. I thought some more about this, and it appears that a reasonably accurate estimation can be made from your shot of the rear of the TC. I roughly measured off my computer's screen, and the diameter of the the plate's opening was @ 1/4", and the rear opening of the TC was @ 7/8" . The ratio of the areas calculated from these rough measurements is @ 1/12 which I confirmed by eyeball on the pic (the actual measurements don't really matter since we're just looking for a ratio). This would represent about a 3 1/2 stop difference (halfway between 1/8 [3 stops] and 1/16 [4 stops], so f2.8 becomes @ f9.5), and with the added 1 1/2 stop difference with the magnification of the TC, starting at f2.8, you'd end up with @ f16 (5 stops slower) with the plate in the TC compared to the lens alone. Not exact, but pretty close, I'm sure.

EDIT: The above is assuming that the rear element of the TC is the same diameter as the inside of the mount, otherwise the numbers in the above paragraph will not be anywhere near accurate.

QuoteQuote:
And I do wish someone buying the adapter come back and have a picture views for the internal of the adapter to see if there is a chance to put in an iris diaphragm. I got two from jinfinace ebay store and the smaller one has a 20mm outside diameter and it fits the inner part that is closest to the lens rear. When I have time, I will share few pictures of my failed attempt in NEX conversion. Something similar can be done with better success on the Q as the lens, image circle from the Auto 110 lens should fit better for the sensor in Q and MFT sensors.
I've got one of the P110 to Q adapters ordered, so I should be able to give some information here about the possibilities of using one of the diaphragms, but I personally doubt that I'd actually go to the trouble of using a variable aperture. With the Q's small sensor, diffraction starts to degrade the image relatively quickly, so I'd only get an absolute max of 2-3 stops of usable aperture. I can do this very cheaply and easily by cutting out a few circles from some heavy construction paper or thin plastic -- not elegant, but serviceable, and I'd probably only use them if tests showed some significant IQ advantage. Since the Q will only use a relatively small section from the center of the image circle, I'm thinking that for most applications, wide open should be at least adequate for most of the lenses I'll be using (all of the primes except the 18 pan-focal). Actually, with the Q, we might be able to use aperture discs mounted on the front of the lenses since vignetting shouldn't be much of a problem.

Scott


Last edited by snostorm; 12-17-2011 at 08:47 PM.
12-17-2011, 04:30 PM   #39
Senior Member
Mock's Avatar

Join Date: Feb 2009
Location: Edmonton
Photos: Gallery | Albums
Posts: 290
QuoteOriginally posted by Mistral75 Quote
Yes indeed...
Ah, didn't see it within the other discussion going on, sorry.
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!
a110, adapters, camera, lens, mirrorless, pentax, pentax q, pentax q10, pentax q7, q10, q7
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
31mm ltd lens build question wishlf Pentax SLR Lens Discussion 7 11-22-2011 12:00 PM
Pentax K-x Build quality msharma Pentax DSLR Discussion 4 10-26-2010 03:52 PM
Dropped a lens! (DA Limited build quality?) ADHWJC Pentax SLR Lens Discussion 10 10-16-2010 10:01 PM
Who build Pentax Optio? arm_jstp Pentax Compact Cameras 3 10-10-2010 05:05 AM
Pentax Should Build an EVIL Camera Biro Pentax News and Rumors 308 02-08-2010 01:10 AM



All times are GMT -7. The time now is 04:46 AM. | See also: NikonForums.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