Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
07-12-2017, 06:15 PM   #16
New Member




Join Date: Jun 2015
Location: Michigan
Posts: 17
Rollei Sonnar 40/3.5 on Q7 (from broken, rusted A26 126 camera)

The shutter and iris were jammed in this...the camera had gotten wet in addition to having a cracked body (before I bought it on eBay)...I removed the shutter and iris blades, so it's always wide open like the projection lenses. I did some filing and epoxied the lens 'barrel' to a C-mount threaded tube sawn-off at a length that lets the lens focus. It's threaded into a PQ/C adapter as a helicoid mount...coarse & gritty, but works...sometimes.

One of my more contrasty salvages...

Attached Images
View Picture EXIF
PENTAX Q7  Photo 
View Picture EXIF
PENTAX Q7  Photo 
07-12-2017, 06:27 PM   #17
New Member




Join Date: Jun 2015
Location: Michigan
Posts: 17
Taylor Hobson (Bell & Howell) 25/1.9 on Q7

Given to me by a friend, C-mount on PQ/C adapter. Very 'glowy' wide open, better a couple stops down (normal for the era, I'm sure). Funny iris, kind of 6 sided, but transitions from round to pinwheel to 12-point-star as it's progressively stopped down, and there are round arcs between the star points...

This is one of the lenses I have that do not focus at proper distance despite having a C-mount (tampering, misalignment?), so I use it for macro (infinity is not reachable on a normal C-mount adapter).
Attached Images
View Picture EXIF
PENTAX Q7  Photo 
View Picture EXIF
PENTAX Q7  Photo 
07-12-2017, 10:03 PM   #18
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: midwest, United States
Photos: Gallery
Posts: 3,341
Excellent photos murrayatuptown. You achieved some nice bokeh with these lenses. Amazed that you could modify a Rollei camera lens for the Q. Amazing.
Thanks for sharing
barondla

Check out the Point & Shoot contests in the Compact Camera forum. Enter #115. The Q is welcome and all brands are allowed.
07-13-2017, 07:50 PM - 1 Like   #19
New Member




Join Date: Jun 2015
Location: Michigan
Posts: 17
Thanks, barondla...for the appreciation and lack of torch and pitchfork...some broken cameras were given to me so someone else avoided the sacrilege of discarding them. so many are not repairable, and I have wasted money repairing cameras to only shoot one roll through...so I'm past that now.

Some of the adaptations involve splinters and blisters, and sometimes there is doubt about the outcome.

It sounds kind of mindless, but I am amazed how much difference the tripod makes...and I should know that...I have at least 4 tripods but it's always more effort to drag them along.

07-15-2017, 05:29 PM - 1 Like   #20
Pentaxian




Join Date: Nov 2014
Location: South Bend, IN, USA
Photos: Gallery | Albums
Posts: 3,012
When I purchased my Q-7, I did so with the intention of adapting a long K-mount lens to create my primary birding kit. After trying out several something-300mm lenses, I settled on the Sigma 70-300 lens. The images aren't quite as sharp as I'd hoped they would be, but I believe that is because the lens has insufficient resolving power. Despite some advice I was given to use only very wide apertures to avoid diffraction, my testing showed this lens works best around f/8-f/11. My original testing was done with a generic adapter, but these days I'm using a Pentax adapter.

I took this picture about ten days ago in a sun-drenched West Virginia meadow.

07-15-2017, 06:30 PM   #21
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: midwest, United States
Photos: Gallery
Posts: 3,341
Looks good reh321. The Pentax adapter is great. With motion it turns out the sharpest results. Do you use a reddot scope on the Q hot shoe?
Thanks for sharing,
barondla

Check out Point & Shoot Contests in the Compact Camera forum. Enter #115. Any brand camera is allowed. The Q is welcome and cell phones are allowed.
07-16-2017, 08:55 PM   #22
Pentaxian




Join Date: Nov 2014
Location: South Bend, IN, USA
Photos: Gallery | Albums
Posts: 3,012
QuoteOriginally posted by barondla Quote
Looks good reh321. The Pentax adapter is great. With motion it turns out the sharpest results. Do you use a reddot scope on the Q hot shoe?
Thanks for sharing,
barondla
No, I'm very much "old school". I start with the lens zoomed out, say 100mm, locate my target, and then zoom in for the picture. With modern lenses, which are typically not parfocal, that means I have to focus multiple times, but ...
07-17-2017, 04:52 AM   #23
Site Supporter
Site Supporter




Join Date: Sep 2006
Location: midwest, United States
Photos: Gallery
Posts: 3,341
Wow reh321. I am even more impressed. Tried that for a while and it just wears me out. Also limited to zooms. My most used adapted lenses are fixed focal lengths. If you get a chance to try a red dot scope it may be habit forming.

Thanks
barondla

Check out the Point & Shoot Contests in the Compact Camera forum. Enter #115. The Q is welcome and all brands are allowed.

11-13-2017, 08:34 AM   #24
Site Supporter
Site Supporter




Join Date: Dec 2016
Location: Silverstone
Photos: Gallery
Posts: 97
Ranking Pentax Legacy Lenses on Q7 with MTF Mapper

I have been trying out several of my film-era lenses on my Q7 + Adapter Q for K Mount Lens in an attempt to rationalise some of my subjective preferences based on bokeh, colour, etc.

I put them all through their paces on MTF Mapper's lens grid target, trying to find their best aperture. In the case of the zooms, I was also trying to find their best focal length.

These results are comparative, using the performance of the 06 wide open @ 45mm as a benchmark, set arbitrarily to 100:

115: D-FA 100mm Macro, f/2.8 - f/4, performance falls off above f/5.6.

108: A135/2.8, f/5.6

103: A70-210/4 @ 70mm, f/6.3

97: M75-150/4 @ 75mm, f/6.3

77: M200/4, f/6.3

The conclusions:
  1. Primes are better than zooms.
  2. If you only have a zoom, stay away from the long end
  3. Most lenses are best about 1.5 stops off wide open
  4. Modern lenses are better than older ones
  5. The M series 200mm f/4 is a disappointment
  6. The D-FA 100mm macro is seriously, seriously sharp
As the focus throw of the 100mm macro is so short at longer distances, I'm wondering if I might use the focus clamp to turn it into a fixed focus lens at f/4. Has anyone tried that, I wonder? What would the hyperfocal be for a 100mm on a Q7, given the extra DOF that the crop factor gives?
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!
adapter, browser, camera, images, lens, lenses, mirrorless, pentax q, pentax q10, pentax q7, pm, post, q-s1, q10, q7, shutter, tone, tripod
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Setting problem with adapted lenses rbelyell Pentax DSLR Discussion 16 04-10-2016 06:26 PM
Still no external manual flash triggering with adapted lenses? Doundounba Pentax Q 19 07-29-2014 12:01 PM
New Q with Adapted Lenses! tjdean01 Welcomes and Introductions 5 05-18-2014 01:21 AM
External flash with adapted lenses baro-nite Pentax Q 24 12-20-2012 07:38 PM



All times are GMT -7. The time now is 05:33 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