Search results for 'back focus' - page 1003
Macro: Extension tubes/bellows/closeup lens
To answer the other points: Magnification for a simple lens system is total extension divided by focal length. (Total extension is the added extension from tubes/bellows + the focusing extension of the lens itself) The more extension you add the more magnification you get. It makes no difference ...
Posted by petrochemist on 01/10/2011 - 13:42
Macro: Extension tubes/bellows/closeup lens
Would this have apperture control? http://www.castlecameras.co.uk/pentax-set-of-extension-tubes-k-100 You can't tell from the picture. Just get a set of sub £10 vivitar tubes or similar from ebay. Set the lens at f8 and follow the stop down metering process. Allow use of aperture setting i...
Posted by dougf8 on 01/10/2011 - 15:40
Stiff CPL filter
Try a soft (6B) pencil lead scribbled across the threads. Graphite is used by locksmiths for lubrication as it does not attract dust and does not flow. It the threads are too big (I assume it's the male thread) it could be due to thick anodising in which case it could be gently scraped back a bit...
Posted by Frogherder on 03/10/2011 - 14:30
DA 18-135WR Comparisons (11 images)
After acquiring my 18-135WR I thought some comparisons might be interesting. All shots taken on K5 as straight Jpegs, max aperture available, matrix metered, Auto Focus. only re-sized in PS no other adjustments. 18mm, 3 lenses Samsung 12-24,18-55WR,18-135WR 35mm, 18-135WR,Sigma 24...
Posted by davex on 01/10/2011 - 14:11
wedding perfect kit
hello, I just got back from a wedding to which i brought only two lenses. although i find it annoying to carry the camera around at wedding, i had a plan in mind - first of all use my 50-150mm - the ultimate portrait lens, and use the 10-17mm fishy + flash at the party (thanks to the person f...
Posted by boudou701 on 02/10/2011 - 19:52
wedding perfect kit
Do it... The 50-135mm has jumped in price a bit recently (I got one of the last at £639 from SRS) but it's brilliant. I was torn between that and a Sigma/Tamron 70-200mm f2.8 but the 50-135mm is smaller and probably lighter. I wouldn't lug it around on a walk but for a fast telephoto it's easy to...
Posted by Dangermouse on 04/10/2011 - 19:46
wedding perfect kit
There are some really good shots there. Definitely stirring my LBA for a 50-150 (or a 50-135)... Personally I would go for the 50-150 (used if you can find one - people tend not to sell them !) over the 50-135. Much faster focusing (the 50-135 is infamous for it's relatively slow focus), HSM ove...
Posted by Frogfish on 05/10/2011 - 06:33
£200 to spend on a Macro Lens?
mmm...what about this DA35mm I keep hearing about though??? Not a macro but a very sweet standard prime... (assuming you mean the 35mm f2.4, I think the DA Ltd 35mm Macro is out of budget!) I think the only way you'll get a genuine macro lens for your budget is by going manual focus. Look for an ...
Posted by Dangermouse on 04/10/2011 - 21:28
Best walk-around WR lenses for rainy city
I only had about an hour in the rain with the K10D before it stopped working. Luckily I left it to dry for about 2 weeks and it came alive again. But no I will not use my gear in wet condition again. Modern electronics can be a wonderful thing. My daughter has put her iPod Touch through the washing ...
Posted by Dave-L on 07/01/2012 - 03:44
Best walk-around WR lenses for rainy city
Would you add the 100mm F2.8 macro WR to the "safe" list? The lens barrel does extend for focusing of course, but the rear glass element is fixed. No, I would not. The focus throw is so large that it will also pump air. I would have thought the seals in the lens would be just as likely to suck in...
Posted by Tyr on 07/01/2012 - 14:37
Best walk-around WR lenses for rainy city
Would you add the 100mm F2.8 macro WR to the "safe" list? The lens barrel does extend for focusing of course, but the rear glass element is fixed. No, I would not. The focus throw is so large that it will also pump air. Thanks, that prompted me to test it using a large party balloon with neck cut ...
Posted by Dave-L on 08/01/2012 - 04:38
Pentax 17-70 v Sigma 17-70
I am looking at getting an improved "standard" zoom to replace my much loved but battered 16-45mm zoom. Now I would love the DA* 16-50 F2.8, but the current cost means it is out of reach. So, the options are either the Pentax 17-70mm F4 or the Sigma 17-70mm F2.8-F4 (now before you start John, I li...
Posted by Offertonhatter on 03/10/2011 - 21:59
Pentax 17-70 v Sigma 17-70
Personally I would recommend getting another 16-45:? I have both the 16-45 and the 17-70 (but not the Sigma). The IQ seems similar and the extra range is handy but the frustrating thing for me is that my 17-70 often fails to lock focus in AFS mode even in average lighting. Works fine in AFC thoug...
Posted by smudge on 04/10/2011 - 09:31
Pentax 17-70 v Sigma 17-70
The Sigma 17-70 (non-hsm version) is the first "upgraded" lens I bought for my K10D a couple of years ago - I replaced it 18months ago with the Pentax DA17-70. My comments are based on the old version of the sigma which I believe is the same optically as the new one: Sharpness - no major/notic...
Posted by simonkit on 04/10/2011 - 09:37
Pentax 17-70 v Sigma 17-70
Hi Iain, I dont know about the Sigma but I have the Pentax- the image quality is good and it is the one lens I'd be reluctant to sell. The comments about focussing issues are fair enough though, from 50mm onward it can struggle to lock on , there is a work around (a light touch on the focus ri...
Posted by japers45 on 04/10/2011 - 11:10
Pentax 17-70 v Sigma 17-70
I'm certainly starting to like it, but as luck would have it, I've just found a very repeatable situation where it fails to focus almost every time. At 70mm, it won't focus on the red spot, but it never misses on the green spot. If I manually focus on the red spot, sometimes it locks, but m...
Posted by ChrisA on 04/10/2011 - 16:06
Pentax 17-70 v Sigma 17-70
My 17-70 f4 only hunts at 50mm + and does so on a fairly regular basis. A little feather on the focus ring locks the focus and this has worked every time so far. I think it can be had new for around £380- for me this is not a lot of money for this type of lens when you consider the silent and fas...
Posted by japers45 on 04/10/2011 - 17:26
Pentax 17-70 v Sigma 17-70
I have had a couple of Pentax 17-70mm's in the past and although I thought the IQ was superb I just couldn't live with the 50-70mm focusing issue. Drove me bonkers and I just don't see why I had to get round it by lightly touching the barrel to get the thing to focus correctly.
Posted by Mike-P on 04/10/2011 - 21:43
Pentax 17-70 v Sigma 17-70
Drove me bonkers and I just don't see why I had to get round it by lightly touching the barrel to get the thing to focus correctly. Come on Mike, you know that you're being unreasonable... all you have to do is improve your technique to get round the alleged limitations of the gear. :twisted: :roll:
Posted by ChrisA on 04/10/2011 - 22:48
Pentax 17-70 v Sigma 17-70
Drove me bonkers and I just don't see why I had to get round it by lightly touching the barrel to get the thing to focus correctly. Come on Mike, you know that you're being unreasonable... all you have to do is improve your technique to get round the alleged limitations of the gear. :twisted: :roll:...
Posted by Mike-P on 05/10/2011 - 08:45
