Search results for 'back focus' - page 988
Noktor 50mm f/0.95
I thought there was a fundamental limitation of the K mount in that it's physically impossible to make lenses faster than f1.2 or so for it? IIRC the mounting just doesn't provide a big enough hole? Presumably if it were possible then Pentax would have done it back in the days when they were huge (i...
Posted by MrCynical on 28/07/2011 - 23:02
Noktor 50mm f/0.95
AFAIK the PK constraints are like this: * Register is ~45.5mm; rear element *could* extend ~12mm; so let's say the minimum focal length without a retrofocal group is ~34mm. * Lens throat is ~42mm wide; but mirrorbox is ~38mm wide, so there's probably no use in having a rear element wider than ...
Posted by RioRico on 29/07/2011 - 15:29
Sigma UK calibration turnaround?
Has anyone sent a lens (and body) to Sigma UK to be calibrated? What was the turnaround time like and did they do a good job? I've just received a new Sigma 30mm f/1.4 from my insurers and a focus adjustment of -10 is not enough to get it sharp. TIA.
Posted by Graham on 28/07/2011 - 12:20
Sigma UK calibration turnaround?
i had them service the focus mechanism on my 50-500mm and the level of customer care was very good. Turn around time was a couple of weeks. Lucky for me they are just 10mins from work so no postage involved. Would certainly recommend them.
Posted by Cayman on 28/07/2011 - 12:47
tokina at-X SD 100-300mm f4
No I can't find it either, I wonder if I am imagining things. Thinking back I think I may have seen the 100-300, and read the review of the 80-400 in the hope it would give me a clue as to the quality. My memory banks are highly deficient I'm afraid! But I did find this The manual focus AT-X 100...
Posted by Pentaxophile on 29/07/2011 - 18:20
tokina at-X SD 100-300mm f4
That's the auto focus version which is really rare, mine is the manual focus version... Have read some say it is sharp at both ends others say it is soft at the long end... Guess I will find out when it gets here.... This is it on a Lumix...
Posted by cabstar on 29/07/2011 - 19:36
Warning about Ricoh Lenses,
Hi all, Since the linking of Pentax name with Ricoh I have noticed a lot more Ricoh Ricohmar lenses for sale on eBay, Am I right in thinking that these lenses will fit onto Pentax DSLRs BUT NOT COME OFF AGAIN as a pin pops into the auto focus hole on the camera mount. I have read of one guy having...
Posted by Still27 on 29/07/2011 - 21:41
Warning about Ricoh Lenses,
Some Ricoh lenses have a rounded pin - these ones have always been fine on my K20D and K5. I've had 4 of these. I believe it is the Ricoh lenses with a flat-ended pin that you have to watch out for. I've never actually seen one of this type. I have just received a Sigma Mini Wide II with a P/KR m...
Posted by PeterKR on 10/09/2012 - 20:59
Warning about Ricoh Lenses,
It's no big deal to remove the dreaded pin. Banish your fears and read on! I have used loads of lenses with the Ricoh pin on Pentax AF cameras (SFXn & Z-1) without any problems. Most independent manual focus 'KA' lenses also had similar pins (some more rounded than others). I never had a proble...
Posted by johnha on 10/09/2012 - 22:09
AF discrepancies at lower zoom levels
I have been testing my Kr for bf and ff. I have found that at the upper zoom of the Pentax 55-300, 37-80, and 18-55, the AF is spot on. But at the bottom zoom level the focal point seem to be a little forward. Is an inherent problem with zoom lenses or is an issue with the KR only. Also more diff...
Posted by surfseen on 31/07/2011 - 00:53
Wide angled
I recently got a Sigma 8-16 and think it is excellent. I posted some sample shots . Be sure to click on the photos to get the full sized versions as the reduced ones look less sharp than they should. It was £375.00 at SRS but it's back up to full price now. Mifsuds are advertising it for £379.00...
Posted by MarkTaylor on 31/07/2011 - 18:50
Pentax 12-24mm bottom of class
Simple solution don't buy Digital SLR magazine :shock: :mrgreen: I don't buy it, I just read it and put it back on the shelf! But I wouldn't not buy a magazine just because they include a test which doesn't fit my own prejudices. Anyway, DSLR User magazine have Pentax sponsorship, and reviewed the K...
Posted by Pentaxophile on 31/07/2011 - 18:19
Pentax 12-24mm bottom of class
Simple solution don't buy Digital SLR magazine :shock: :mrgreen: I don't buy it, I just read it and put it back on the shelf! But I wouldn't not buy a magazine just because they include a test which doesn't fit my own prejudices. Anyway, DSLR User magazine have Pentax sponsorship, and reviewed the K...
Posted by Algernon on 31/07/2011 - 18:52
Pentax 12-24mm bottom of class
Don't hold back Robin. Say what you really feel! I am not sure why anyone pays attention to them. Well, the adverts are quite interesting... I flip straight to the Mr Cad second hand listings etc, unless there's a 'controversial' test to pore over.
Posted by Pentaxophile on 31/07/2011 - 23:58
Pentax 12-24mm bottom of class
Don't hold back Robin. Say what you really feel! I had better not. This is a family forum. ;-)
Posted by rparmar on 01/08/2011 - 00:46
Pentax 12-24mm bottom of class
The last time I bought a photography magazine was in 1985 I wonder how the widespread ability of 'other sources of naughty pics' affected the sales of photography mags? My dad had a stack of them in his wardrobe (under his ginormous tin of weed) and they were quite racy back then! :twisted:
Posted by Pentaxophile on 02/08/2011 - 18:20
Pentax 12-24mm bottom of class
The last time I bought a photography magazine was in 1985 I wonder how the widespread ability of 'other sources of naughty pics' affected the sales of photography mags? My dad had a stack of them in his wardrobe (under his ginormous tin of weed) and they were quite racy back then! :twisted: I had a ...
Posted by Smeggypants on 02/08/2011 - 18:43
Pentax 12-24mm bottom of class
Your point continues to be contradictory in that you condemn a reviewer but extol someone, anyone, who happens to post on a forum as having an equal insight. How can this be when your reviewer has the equipment and backup necessary to do the review, the cost of which is very high by the way, plus...
Posted by Smeggypants on 03/08/2011 - 23:40
Pentax 12-24mm bottom of class
That's very interesting Smeggypants, so are you saying that all publishers became corrupt? If so, what form did this corruption take and what was its purpose? The lead on question from that would be, how do web based publishers (of which you yourself are one, having your own website, as do I) dif...
Posted by Smeggypants on 04/08/2011 - 02:02
Pentax 12-24mm bottom of class
My post also made it clear that it was comparing commercial 'corruptness' with people with no commercial bias. Of which I am amongst the latter. meaning: "meant to say all publishers EXCEPT SMEGGYPANTS... blah, blah, blah, corrupt...etc...etc..etc...:twisted:" :roll::roll: I'll go back to my ...
Posted by Don on 04/08/2011 - 02:20
