Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11-02-2014, 09:58 AM   #1141
Site Supporter
Site Supporter
akptc's Avatar

Join Date: Feb 2008
Location: USA
Photos: Gallery
Posts: 551
QuoteOriginally posted by Auzzie-Phoenix Quote
Actually I might have an explanation for this. I have the sigma 75-300mm f/4-5.6 DL autofocus zoom and it only works manual as well, but I have noticed something about it. Setting aperture ring to auto and having the camera in AF.S it will keep track of the focal length when you adjust the slide but that's about all the data it transmits. The mount doesn't seem to be set up properly. I have to hold the release button and further tighten mine just to get the camera to register that the lens is there, else I get the blank F-- and no reaction. Due to the incorrect nature of the mount, I believe that this causes the AF to not function both by not having the data pins in the correct place, or the screw drive for the af adjuster in the correct spot as well. Though this behavior causes me no issues since I shoot manually regardless. Mind you i have no clue if this is actually the case with your lens.
Interesting. I tried the lens on my K5 today, the camera did not ask for focal length and the lens behaved like an "A" lens; however, I was able to dial-in 2.8 via the camera while the max aperture possible is of course 4.0. Very odd.

11-02-2014, 11:23 AM   #1142
Site Supporter
Site Supporter




Join Date: Sep 2014
Photos: Albums
Posts: 1,018
QuoteOriginally posted by akptc Quote
Interesting. I tried the lens on my K5 today, the camera did not ask for focal length and the lens behaved like an "A" lens; however, I was able to dial-in 2.8 via the camera while the max aperture possible is of course 4.0. Very odd.
Yes, I can dial-in an aperture on mine in manual, and in auto it goes by metering, so it does act like an A series.
11-02-2014, 03:00 PM   #1143
Senior Member
EJMzagsfan's Avatar

Join Date: Mar 2012
Location: Idaho
Photos: Albums
Posts: 241
17-50 2.8, it was raining and there were drops on the front element, but it doesn't bother me all that much.


11-02-2014, 04:35 PM   #1144
Site Supporter
Site Supporter




Join Date: Sep 2014
Photos: Albums
Posts: 1,018
QuoteOriginally posted by Auzzie-Phoenix Quote
Actually I might have an explanation for this. I have the sigma 75-300mm f/4-5.6 DL autofocus zoom and it only works manual as well, but I have noticed something about it. Setting aperture ring to auto and having the camera in AF.S it will keep track of the focal length when you adjust the slide but that's about all the data it transmits. The mount doesn't seem to be set up properly. I have to hold the release button and further tighten mine just to get the camera to register that the lens is there, else I get the blank F-- and no reaction. Due to the incorrect nature of the mount, I believe that this causes the AF to not function both by not having the data pins in the correct place, or the screw drive for the af adjuster in the correct spot as well. Though this behavior causes me no issues since I shoot manually regardless. Mind you i have no clue if this is actually the case with your lens.
I actually need to retract this. While the camera doesn't report an F stop value, the autofocus has started working without doing the "overshift" maneuver. I believe my issue with the autofocus not functioning was due to not having the settings for manual lenses enabled in the k-50. The last time I had used the lens was prior to obtaining my smc pentax-m 28mm f/2.8 prime, so I hadn't enabled aperture ring mode 2 on page 4 of the custom menu, nor had I set the green button for stop down metering yet.

However, what this means is that your zoom might still work with autofocus. Just enable the manual aperture setting in custom menu, as well as green for stop down meter in manual, then set camera to af.s with the 70-210mm zoom on. Since the camera doesn't register an f-stop number, you'll have to use that manually instead of setting the aperture ring on the lens to the A setting. I used my AF for quite a bit today playing with the camera handheld, even got some decent moon shots without the tripod. Although with the weather being colder and having to focus the heavier lens, it sure did eat away at the battery quickly.

11-02-2014, 07:19 PM   #1145
Site Supporter
Site Supporter




Join Date: Sep 2014
Photos: Albums
Posts: 1,018
Taken at the lake today with the 75-300mm DL zoom (with the now apparently working autofocus). Apparently in EXIF the lens thinks it's an 18-200mm DC F/3.5-6.3? Must use same logic chip or something. Either that or it was taken apart and frankensteined... I don't know either way, but it sure is a nice lens.


Last edited by Auzzie-Phoenix; 11-02-2014 at 07:20 PM. Reason: blah blah
11-03-2014, 04:33 PM - 1 Like   #1146
Senior Member




Join Date: Mar 2014
Posts: 236
Sigma 75-200 3.8 AF @4



11-04-2014, 12:26 AM   #1147
Site Supporter
Site Supporter
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 10,137

Pentax K5IIs - Sigma 8-16mm f/4.5-5.6 EX DC @ 8mm f/8 ISO1250


11-04-2014, 02:23 AM   #1148
Veteran Member
Pablom's Avatar

Join Date: Feb 2010
Location: Jerusalem
Posts: 1,940
Sigma 24mm f/2.8 and Velvia 100


0011
by Pablo Margulies, on Flickr

11-04-2014, 05:02 AM   #1149
Loyal Site Supporter
Loyal Site Supporter
ivanvernon's Avatar

Join Date: Oct 2012
Location: Medina, OH
Photos: Albums
Posts: 5,300
QuoteOriginally posted by Cabessius Quote
Sigma Super-wide II 24mm f2.8

1/100s
f8
ISO 100



Very nice, but what is this structure? It reminds me of some of the ancient architecture seen in India.
11-04-2014, 05:15 AM   #1150
Pentaxian




Join Date: Dec 2012
Photos: Gallery
Posts: 1,108
Sigma 70 – 300 APO DG Macro

This consumer zoom gets usually quite bad reviews. However I like my copy – at 10 MP sensor it can be sharp at 100% crop, so If you do not need really fast AF this can be one of the solutions.








Last photo was made using Pentax Q at 220 mm/5.6.
11-04-2014, 05:53 AM   #1151
Loyal Site Supporter
Loyal Site Supporter
ivanvernon's Avatar

Join Date: Oct 2012
Location: Medina, OH
Photos: Albums
Posts: 5,300
Sigma Zoom-Master 35-70 mm f 2.8-4.0 multi-coated

I picked up this old Sigma manual focus zoom lens on an older model film camera, and never tried it out until this morning. Here are a few shots on the K-7 in early morning light (around 7:00 a.m. EST). The lens has an A setting, so works on all K-7 modes, and these shots were Av or manual. I would appreciate any thoughts/reactions anyone would care to offer on lens performance, not composition or topic. These are right out of the camera, no PhotoShopping. I have not been able to find any reviews of this old film lens.

ADDED NOTE: EXIF shows 50 mm FL for all three photos, but these readings are incorrect. The pumpkin, first shot, is more like 35 or 40 mm, and the last shot of my wife's greenhouse is 70 mm. The middle shot of the wishing well is intermediate, probably somewhere around 50 mm.
Attached Images
View Picture EXIF
PENTAX K-7  Photo 
View Picture EXIF
PENTAX K-7  Photo 
View Picture EXIF
PENTAX K-7  Photo 

Last edited by ivanvernon; 11-04-2014 at 05:59 AM. Reason: To add focal length information given incorrectly in EXIF.
11-04-2014, 06:35 AM   #1152
Site Supporter
Site Supporter
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 10,137

Pentax K5IIs - Sigma 180mm f/3.5 APO EX @ f/5.6 1/500th ISO 80
11-04-2014, 09:43 AM   #1153
Senior Member




Join Date: Mar 2014
Posts: 236
more with the 75-200 F3.8 AF





11-04-2014, 09:53 AM   #1154
Pentaxian
Jonathan Mac's Avatar

Join Date: Apr 2009
Location: Madrid, Spain
Posts: 6,780
QuoteOriginally posted by ivanvernon Quote
I picked up this old Sigma manual focus zoom lens on an older model film camera, and never tried it out until this morning. Here are a few shots on the K-7 in early morning light (around 7:00 a.m. EST). The lens has an A setting, so works on all K-7 modes, and these shots were Av or manual. I would appreciate any thoughts/reactions anyone would care to offer on lens performance, not composition or topic. These are right out of the camera, no PhotoShopping. I have not been able to find any reviews of this old film lens.

ADDED NOTE: EXIF shows 50 mm FL for all three photos, but these readings are incorrect. The pumpkin, first shot, is more like 35 or 40 mm, and the last shot of my wife's greenhouse is 70 mm. The middle shot of the wishing well is intermediate, probably somewhere around 50 mm.
Soft and low contrast. Based on these photos I'd get rid of it.
11-04-2014, 07:39 PM   #1155
Pentaxian
Weevil's Avatar

Join Date: May 2012
Location: Near Montréal, Québec
Photos: Gallery
Posts: 3,102
Sigma 180mm macro f3.5

Hosta sp. (Abiqua Blue Crinkles)
by Curculion, on Flickr
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!
address, birds, bread, club, colors, dg, email, f4, flickr, flower, idaho, images, k-3, lens, lenses, macro, nov, pentax lens, post, ruins, sage, shot, sigma, sigma lens, sw, texas, thanks, time, usa
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
300mm plus Lens Club: discuss your long lenses cooldude14es Lens Clubs 34589 13 Minutes Ago 01:42 AM
Soviet lenses club Voe Lens Clubs 3976 1 Hour Ago 12:40 AM
SIGMA 10-20mm CLUB Jewelltrail Lens Clubs 3836 3 Days Ago 08:19 AM
SIGMA 8-16mm CLUB ManhattanProject Lens Clubs 837 12-17-2019 02:29 AM
The 'Hey this lens has glass elements in it' Lens Club Igilligan Lens Clubs 50 11-14-2010 11:07 PM



All times are GMT -7. The time now is 01:56 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