Search results for 'back focus' - page 701
sigma 18-50 ex - problems! again! Anyone else experiencing!
Which camera body? I had consistent back focus issues with the K10D (but didn't with the *ist-D). As it turned out, every lens back focussed and it was more apparent on wide apertures (like f/1.4). There's a thread on how it could be adjusted ;) You may find a tripod test with something like the...
Posted by MattMatic on 06/03/2008 - 14:14
sigma 18-50 ex - problems! again! Anyone else experiencing!
Hi Matt, one day i'll have a word with the Queen and get you knighted as you are always a great help. Tried some of the links you mentioned last time and even tinkered with the af adjust. But can't get the blighter to work. The prob is also when I switch to my lovely Pentax 70-320 it will not ...
Posted by Bluewhistle on 06/03/2008 - 14:55
sigma 18-50 ex - problems! again! Anyone else experiencing!
Matt, Glad to see an evil Nikonian has provided the world with a very useful chart and an insightful writeup. Thanks for passing it along. I'm using it on manual focus Spotmatic, Super Program and P30 bodies with my 50mm Macro prime, to see how well the mirrors are adjusted. 'Course, it...
Posted by Mac on 06/03/2008 - 15:31
sigma 18-50 ex - problems! again! Anyone else experiencing!
LOL @ the knighthood :D :lol: The prob is also when I switch to my lovely Pentax 70-320 it will not be calibrated. Not sure what you mean?? Did you mean the 80-320? There are other issues that can occur with the 80-320 - especially not being able to focus on infinity. But that's another story ;) ...
Posted by MattMatic on 06/03/2008 - 15:48
sigma 18-50 ex - problems! again! Anyone else experiencing!
Thanks Matt. Lens is the Sigma 18-50mm ex dc. I did a test with a ruler and tried to focus on one point. The lens appears to focus on my chosen number (always 16cm - don't know why I choose this) but will always on the photo show as focused on 17cm. I always compare the depth of field to t...
Posted by Bluewhistle on 06/03/2008 - 16:23
sigma 18-50 ex - problems! again! Anyone else experiencing!
Blue, You MUST use something like the Focus Test Chart ;) NOT a ruler. You cannot be absolutely sure that the centre focus point is accurately aligned. The FTC has a thick black bar in the middle that you focus on at 45 degrees. There are ruler markings at the far right and left edges that will ...
Posted by MattMatic on 06/03/2008 - 16:37
Telephoto >300mm
I have a Sigma 400mm F5.6 autofocus. The good thing is the speed of autofocus which is the fastest of any lens I have, probably due to the internal focusing, fast even though I have a DS. I use it for my sons football so you can get a close up at the other end of the football pitch. I don't use it f...
Posted by JohnMcD on 11/03/2008 - 17:24
Telephoto >300mm
A fixed focal length gives better results than a zoom, so for wildlife that's what I would go for. Avoid 2X converters is also my advicem, you can usually crop a pictute with sharper results than a converter gives without slowing the lens further. If you aren't bothered about auoto-focus, ther are l...
Posted by MX veteran on 11/03/2008 - 17:51
Macro: Pentax vs Sigma
I love the D-FA100! It is a little noisy (AF-wise) but not considerably more so than any other Pentax lens (and at macro ranges you tend to use MF anyway) and there are times when the lack of a focus limiter can be, er, limiting but overall I find the optical quality to be absolutely first rate. T...
Posted by hefty1 on 07/03/2008 - 16:58
Macro: Pentax vs Sigma
That link is the first bit of negativity i have read about the Pentax :!: I agree with Hefty its a superb lens although i have not had this lens very long and not used it for portraits as yet. Also i have used it predominatly with a ring flash attached so i have been stopping it down somewhat a...
Posted by Clarky on 07/03/2008 - 21:19
Macro: Pentax vs Sigma
I'd have a look at www.photodo.com to see if it's tested there. I have used the D-FA lens but only for some test shots but it does seem fine. Sharp, crisp, nicely designed. For macro shots I don't use AF. Manual focus is much better for most macro subjects. But from what I've seen I would happily...
Posted by johnriley on 07/03/2008 - 21:55
Macro: Pentax vs Sigma
The Photozone site www.photozone.de doesn't give the DFA 100 a particularly sparkling review either, looks pretty ordinary. The Tamron which is also tested on the Pentax K10D gets a better review as does the old FA100. Both the Tamron and old Pentax lens are more consistent from wide open with their...
Posted by JohnMcD on 11/03/2008 - 18:31
Sigma 17-70 - HDR like images ?
Thanks for getting back to me Simon. Sorry to be a pain but I assume that you shoot in RAW. In which case what software do you process with? From the "natural" look of many of your images I assume that postprocessing is minimal......I'm struggling with RAW processing and have more or less...
Posted by Donut on 10/03/2008 - 17:10
Sigma 17-70 - HDR like images ?
Hi Simon, it's me again with another question. I havn't got round to buying the Sigma 17-70 yet and not gone off the idea either, just watching the exchange rates € V's Stg as I'll be in the Uk next Month. Have been reading about Pentax Lens 17-70 to be released this year. " The smc Pentax-D...
Posted by daltoned on 10/03/2008 - 18:56
Sigma 17-70 - HDR like images ?
Hi Simon, it's me again with another question. I havn't got round to buying the Sigma 17-70 yet and not gone off the idea either, just watching the exchange rates € V's Stg as I'll be in the Uk next Month. Have been reading about Pentax Lens 17-70 to be released this year. " The smc Pentax-D...
Posted by simonkit on 10/03/2008 - 19:38
16-50 Purple Fringing
Hi Dan, The quality of your testing was obviously much better than mine :) I was impressed by your duck pictures with the 300 - I guess the Pentax people let you walk around outside the shop with it? R Only noticed once I was at home at the pics were on the PC, I don't think you can really ju...
Posted by Daniel Bridge on 10/03/2008 - 10:34
16-50 problem ?
hi all, I am not sure if there is something wrong with my lense, I both have the 16-50 and the 50-135, very happy with the second one no issue at all, the 16-50 is actually very stiff on the zoom ring, is that normal ? i noticed also that there is maybe some back focus issue, i would like to post a...
Posted by claudio on 10/03/2008 - 20:39
16-50 problem ?
My 16-50 is a little stiff at the wide end but smooth after about 28mm. I think this is due to the two barrel extension system. The first is stiffer, the second is smoother. As for backfocus, IŁe found this is my K10 being miss calibrated. I fixed it using a hacked firmware and now what I see in foc...
Posted by Tyr on 17/03/2008 - 09:29
16-50 problem ?
My 16-50 is a little stiff at the wide end but smooth after about 28mm. I think this is due to the two barrel extension system. The first is stiffer, the second is smoother. As for backfocus, IŁe found this is my K10 being miss calibrated. I fixed it using a hacked firmware and now what I see in foc...
Posted by Mongoose on 17/03/2008 - 12:39
16-50 problem ?
I think what Tyr's saying is that he had the same problem as me, ie when something looked to be pin-sharp in the viewfinder it was out of focus on the sensor. I too used the firmware hack (in conjunction with the calibration chart) and find it's made a world of difference - what I see in the viewfi...
Posted by hefty1 on 17/03/2008 - 14:54
