Search results for 'sensor cleaning' - page 137
The Best Value Pentax Lens?
Yes, (failing medium format), 35mm film or full frame are the way forward for shallow DOF stuff. Where did I put that Ektar? :lol::oops: you won't get shots looking like that on a Pentax (unless you get a Sigma 30mm f1.4) :wink: There is one Pentax DSLR though and it can get shots looking even be...
Posted by Pentaxophile on 23/08/2011 - 18:50
Lens overlap
What John says is right. In principle, 18mm at f5.6 is 18mm at f5.6 (if it really is set to 18mm). However, here are a few reasons why things will be different: -Any distortion the two lenses have is likely to be different - in particular, for the 18-55, 18 is at its widest angle, whereas a 12-...
Posted by Adqam on 25/08/2011 - 13:28
35mm only or digital
They should be fine and if they have an "A" setting on the aperture ring (if there is one) then totally functional. Lenses designed for film are generally OK, but sometimes not as good as ones designed for digital. This is primarily because digital lenses have a telecentric design, where light ra...
Posted by johnriley on 26/08/2011 - 14:08
Tamron 18-200mm
as said john is wrong and the tamron was made fo digital and cropped sensor specifically, http://www.tamron.co.jp/en/data/digital/a14.html and my husband had one and he said he would take them over the 18-55mm and 50-200mm pentax kit lenses as the tamron is just as good in one lens unless you ha...
Posted by pentaxanne on 30/08/2011 - 07:34
35mm 2.4 vs 2.8 macro or 40mm 2.8 Ltd
You will see from my comment on the that I was right there with the DA35 Limited as it was released. I think that the comments of Carl and mark are right on the money. I also think that a good deal of their wonderment was down to the camera and sensor (K20D). I actually ended up getting rid of ...
Posted by rparmar on 04/09/2011 - 21:19
older zooms
I have found the Pentax A35-105 to be a very useful older zoom. It has the "A" setting, making it easier to use on DSLR than the K and M series zooms in achieving correct exposure. It is very sharp and produces wonderful colours. The drawback is the focal length. On a crop sensor 35mm is for most pu...
Posted by bjolester on 06/09/2011 - 00:09
older zooms
I have found the Pentax A35-105 to be a very useful older zoom. It has the "A" setting, making it easier to use on DSLR than the K and M series zooms in achieving correct exposure. It is very sharp and produces wonderful colours. The drawback is the focal length. On a crop sensor 35mm is for most pu...
Posted by Dodge69 on 06/09/2011 - 21:32
Zoom Lens- Close Focus Distance
I think you're mixing things together a bit. Minimum focus distance is the minimum focus distanced measured from the sensor, nothing more nothing less. Dof is another thing not directly related to this. The Depth of field is more or less entwined with the magnification, the higher the magnifica...
Posted by Anvh on 05/09/2011 - 15:22
Now what am I doing wrong?
There's a lot of nonsense being posted in this thread about people not having ANY exposure problems with lenses on Pentax cameras when it's well documented that there is :shock: :mrgreen: :wink: This thread is one of many showing graphs etc. explaining the problems. But that thread (near to...
Posted by layingback on 26/09/2011 - 12:10
DIY PK-mount Carl Zeiss Jena Pancolar 50/1.8
Ive had a Carl Zeiss Jena Pancolar 50mm f/1.8 for about a year and quite like its rendering and sharpness, but I don't really use it much, for a comparatively expensive 50mm lens. One of the options available to our Canon-using compatriots is to use Prakticar-branded Praktica B mount versions of...
Posted by sorted78 on 21/09/2011 - 22:54
tamron sp 300 f5,6 AD 2
Excellent compact lens. The 'macro' is useful with short distance possible. Bokeh very good. Was choice onmy K100D but had large purple disc on K-7...some kind of sensor reflection. Not sure onthe K-5. Pete
Posted by Transit on 23/09/2011 - 21:51
Do you REALLY need more lenses?!
At the moment at least I'm completely happy with my lens line-up: DA12-24, FA 35mm, DA17-70 & DA 55-300 - covers everything I need and the IQ of them all is excellent. Previous to buying the K5 I was considering something slightly faster than the DA12-24 for interior shots but the high iso abil...
Posted by simonkit on 28/09/2011 - 09:59
Macro: Extension tubes/bellows/closeup lens
The principle and the effect of them is same, the difference is in the usage of them. Using the bellows you can increase the picture distance (between the lens and the sensor) stepless but it is vulnerable and isn't too practical on the site. The tube-set is well usable but you can increase the pi...
Posted by szgabor on 01/10/2011 - 08:10
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
£200 to spend on a Macro Lens?
I was going to suggest the Tamron too, namely the 90mm F2.5 Adaptall, which is a seriously sharp lens. But it is MF only. Best thing is to trawl around the second-hand places to see if you can find FA 50mm F2.8, FA 100mm or Sigma's 50mm, 70mm, or possibly the most available second hand 105mm macro...
Posted by Transit on 04/10/2011 - 03:10
Dismantling an smc Pentax-M 75-150mm f4
I started another thread about fungus on this lens, thinking it was on the outside, but on closer inspection and an attempt at cleaning it with acetone, it actually appears to be on the inside of the front element. Does anyone know how to remove the front element? I'd like to have a go at cleaning i...
Posted by aliengrove on 05/10/2011 - 12:07
Dismantling an smc Pentax-M 75-150mm f4
I've got one of these, similarly afflicted, but haven't got around to cleaning it up yet. My first stop would be to try to unscrew the trim around the front element (I've used a rubber sink plug or an M42 rear lens cap with strategically placed bits of double sided tape around the trim ring you'...
Posted by sorted78 on 05/10/2011 - 12:20
Lens Cleaning
I see plenty of information on lens cleaning and they all seem to discuss and show cleaning of front optics. I have noticed that at times the rear optics of one of my lenses looks as if it could be a little dirty, viewed in certain lights/angles/conditions. Question When the time comes should the...
Posted by davidrobinson on 07/10/2011 - 20:26
Lens Cleaning
I use a microfibre cloth or a Calotherm cloth. Or if its really greasy a drop of Eclipse and a pec pad.
Posted by dougf8 on 07/10/2011 - 20:54
Lens Cleaning
I've never used it before, but it supposed to be the best.. ROR... I've just ordered some from Eddie Houston on ebay and I don't think he'd recommend anything that wasn't as good as he says it is £15.19 delivered
Posted by Algernon on 08/10/2011 - 09:06
