Search results for 'sensor cleaning' - page 145
New 560mm minimum focus distance
[quote:3496ace15f="K10D"]Well the games afoot. Sony have announced a dust and moisture resistant 500mm f/4 along with a new FF DSLR. Also 4 metre min focus. So there will be plenty of competition for peoples long lens money. Best regards gotta remember the 500 on a ff is like 500 fov.. 550 on a...
Posted by Don on 09/02/2012 - 13:54
New 560mm minimum focus distance
I think Sony face a bit of a dilemna with the new FF camera. If they keep the translucent lens tech they basically have a cmaera that RESTRICTS the amount of light to the sensor (photography is all about light no?). if they go back to a Pentaprism they are saying the SLT isnt good enough for a pr...
Posted by japers45 on 09/02/2012 - 18:23
New 560mm minimum focus distance
[quote:3496ace15f="K10D"]Well the games afoot. Sony have announced a dust and moisture resistant 500mm f/4 along with a new FF DSLR. Also 4 metre min focus. So there will be plenty of competition for peoples long lens money. Best regards gotta remember the 500 on a ff is like 500 fov.. 550 on a...
Posted by K10D on 09/02/2012 - 23:47
Architectural lens / Perspective control lens
That lens is designed for 35mm film and not really much use on an APS-C sensor. Even the 28mm Pentax Shift isn't much use on one. Until Pentax or someone else manufactures a 18mm shift then John's suggestion is really the only option.
Posted by gartmore on 10/02/2012 - 17:15
Architectural lens / Perspective control lens
I have never tried it but… could you use the sensor shift feature of the K5 (or K7) to achieve the same effect as a tilt &shift lens? (well the shift part anyway).
Posted by Dave_Evanson on 28/03/2012 - 14:38
Architectural lens / Perspective control lens
I have never tried it but… could you use the sensor shift feature of the K5 (or K7) to achieve the same effect as a tilt &shift lens? (well the shift part anyway). The deviation is far too small.
Posted by rparmar on 28/03/2012 - 15:02
Confused on equivalent focal length
The focal length stated on lenses is always the actual focal length that you would get on a FF camera. So the 135 when put on a crop sensor camera would give you a 205 equivalent focal length. The 50-200 would give you a 75-300equivalent focal length. The DA designation does not mean that the fo...
Posted by vrapan on 13/02/2012 - 16:13
Confused on equivalent focal length
The focal length stated on lenses is always the actual focal length that you would get on a FF camera. Take off the full frame camera. The focal length is the distance between the nodal point and the sensor/film plane at infinity. It means that a 135mm lens is always 135 mm, be it on a APS-C, 35...
Posted by pentaxian450 on 13/02/2012 - 18:39
Confused on equivalent focal length
Having learnt photography on 35mm flim, I find the crop factor quite helpful. Especially when it comes to comparing different bodies. But I can't see why it was ever described as effective focal length, that has caused so much confusion! The crop factor is a function of the camera (sensor) whilst ...
Posted by petrochemist on 14/02/2012 - 13:59
Confused on equivalent focal length
There is no problem there. Forget the last digit on your zoom or tele, and divide by three, and you have your enlargement (reduction) ratio right there. Couldn't be simpler. Beside, some "new generation" photographers never worked with 35 mm cameras, so why confuse them right there. Your sugges...
Posted by petrochemist on 15/02/2012 - 11:19
release date for 560mm ???
I think the Sigma SD1 camera is a case in point here. It has dropped in price by 60% overnight and has been renamed the SD1 Merrill but it is essentially the same camera- any early adopter would surely feel utterly robbed- even though Sigma are talking about vouchers for money off their products as ...
Posted by japers45 on 18/02/2012 - 14:39
Reverse lens for macro photography
Would suggest you type "reversing ring" into google for a mass of detailed information (far more than you're likely to get in a relatively short thread). The basis is that you need a ring which has two male threads which fit into the filter threads of the two lenses you opt to use, so you will ne...
Posted by Frogherder on 20/02/2012 - 09:27
Ok Ok I know! 17-70 Vs 16-50
A D7000 with a greasy sensor that needed cleaning every fifty shots A D700 that needed the mount shimming brand new and eventually a chassis replacement. A D3 with a misaligned viewfinder. Then there's the Lenses, I shot NIKON for 25 Years bot semi pro and pro but no longer, there's only so much ...
Posted by jules on 21/02/2012 - 11:49
Ok Ok I know! 17-70 Vs 16-50
A D7000 with a greasy sensor that needed cleaning every fifty shots A D700 that needed the mount shimming brand new and eventually a chassis replacement. A D3 with a misaligned viewfinder. Then there's the Lenses, I shot NIKON for 25 Years bot semi pro and pro but no longer, there's only so much ...
Posted by K10D on 21/02/2012 - 13:09
Ok Ok I know! 17-70 Vs 16-50
I use filters on all my lenses, primarily to protect the lens coating from the cleaning it would otherwise require. Before 'digital filters' were an option, optical filters were necessary for many different effects and lenses shouldn't be affected significantly when quality filters are fitted. Ma...
Posted by johnha on 29/02/2012 - 23:02
Ok Ok I know! 17-70 Vs 16-50
This thread has become really interesting. I did a test last night (not scientific of course) where I shot a still life of a porcelain ornament with my DA 16-45, both with and without a UV filter. The subject was chosen because I could control lighting and focus to be 100% identical between the tw...
Posted by davidstorm on 02/03/2012 - 09:45
Ok Ok I know! 17-70 Vs 16-50
Sellers simply use the fact a filter has been on a lens as a selling point, and it is in the sense that it implies that they have kept their cleaning excesses off the lens and scratched the filter instead.... In fact, cleaning a lens should be very infrequent, but if it's going to be overdone the...
Posted by johnriley on 05/03/2012 - 14:42
SDM Lenses
I have a number of Pentax lenses with SDM... the 16-50; 50-135; 200 and 300. They are all beautiful lenses and I have not had an SDM failure yet (and they do get a decent amount of use). The only odd occasion where there has been any issue has been an issue with contacts rather than the SDM per se. ...
Posted by matwhittington on 25/02/2012 - 10:33
Pentax SMC DA 55-300mm F4-5.8 ED Lens
The Greenfinch I posted this week in my portfolio is the same lens at 300mm (equivalent to 450mm on a 35mm size sensor) from about three metres away in our garden. The robin before it is at about six metres away in our local reservoirs park. I don't tend to use at 55mm as my standard 18 - 55mm ki...
Posted by wvbarnes on 26/02/2012 - 11:54
Sigma 70mm or Tamron 90mm f2.8
70mm isn't far off 105mm on a full frame sensor so it still gives you a reasonable working distance. I have the Sigma 70mm macro and it is an extremely sharp lens whilst the resistance to flare is also excellent and a big improvement over macro lenses of a few years ago.
Posted by EDB on 28/02/2012 - 19:20
