Search results for 'sensor cleaning' - page 106
Which Wide Prime?
There is no way on earth the 21mm will focus anything like 1 cm. I think you missed a zero, possibly 10cm. Mike 20cm to be exact. :wink: Are these metered from the sensor or lens-mount btw?
Posted by Anvh on 21/06/2009 - 19:36
Which Wide Prime?
Trying it now I'd say 20cm from the sensor.
Posted by mikew on 21/06/2009 - 19:51
Which Wide Prime?
There is no way on earth the 21mm will focus anything like 1 cm. I think you missed a zero, possibly 10cm. Mike 20cm to be exact. :wink: Are these metered from the sensor or lens-mount btw? Hi Stefan,I would say the above is about right.I found out where i read about the 1cm distance it was the ...
Posted by Tony-O on 21/06/2009 - 21:31
Whats my focal length!
As I understand it there is a 1.5x multiplying factor with the APS-C sensor which makes your figures right The focal length of the lens cannot change, but gives the impression of the longer length So both of the lenses you mentioned act in the same way when used on your K-m If you are asked to ...
Posted by leytono on 21/06/2009 - 05:56
Whats my focal length!
Yeps only the angle of view (AOV) change but also some other things change as well since the circle of confusion (COC) is also smaller. COC is how big a spot can be before it becomes unsharp. With 35mm that is 0.029 mm with an APS-C sensor that is 0.018 mm. That means that the dof becomes small...
Posted by Anvh on 21/06/2009 - 09:21
Whats my focal length!
Great thanks for the help - everything makes much more sense now :D I'm not sure if a full frame sensor would suit my needs - there were a couple of shots I took yesterday where it would have been usefull having a wider angle or view, but I don't think I would want to be without the camera I have...
Posted by PENTAX-PLANET on 21/06/2009 - 11:04
DA* 50-135 wow wow wow wow wow wow!!!!!!
It depends on how you measure Bob but the number giving is from the sensor. I believe it's one meter though, at least got that feeling. Wonderful photos on flickr, like how IMGP0663 came out.
Posted by Anvh on 22/06/2009 - 22:23
DA* 50-135 wow wow wow wow wow wow!!!!!!
It depends on how you measure Bob but the number giving is from the sensor. I believe it's one meter though, at least got that feeling. Wonderful photos on flickr, like how IMGP0663 came out. Perhaps it's just me then! I do have an experiment I use when I get a new lens, I sit in the exact sam...
Posted by Snootchies on 22/06/2009 - 22:49
M 200mm f4 K
No problem Jeanette, sorry I didn't do it sooner. I think you use an wider apeture so more light comes on the sensor but you forgot to adjust the shutterspeed. :wink: You need to premit aperture ring as a setting yes. You can use M-mode and by pressing the green button it will set the correct s...
Posted by Anvh on 25/06/2009 - 20:25
What do you use your 50mm 1.4 af for?
Virtually everything. I just have the 1.8/55 K. Still life, Landscapes, Details of architecture, City life. I just love that focal length on a AP-C sensor. In the Old Filmdays the 85 mm was my favourite FL also. Martin.
Posted by Malo1961 on 23/06/2009 - 18:26
Fungus problem on SMC 75-150. Advice please.
What of my original question? Is it possible to continue to use the lens without contaminating the camera body? Yes. The fungal spores are already inside your camera body, they're inside every lens you own and they're part of the air you breathe day-in and day-out. Under normal circumstances t...
Posted by hefty1 on 02/07/2009 - 19:38
Are 'fast' lenses less important with modern DSLRs?
Still f/2.8 and f/4 is one f-stop if that makes a difference indoors of shooting iso3200 or iso1600 then that is quite a difference in noise. Good the sensor are getting better but a lower iso will always look better. Also the narrow DOF is important for some types of shooting as well. The real ...
Posted by Anvh on 08/07/2009 - 11:48
Are 'fast' lenses less important with modern DSLRs?
Still f/2.8 and f/4 is one f-stop if that makes a difference indoors of shooting iso3200 or iso1600 then that is quite a difference in noise. Good the sensor are getting better but a lower iso will always look better. Also the narrow DOF is important for some types of shooting as well. The real ...
Posted by BODYHEAT on 08/07/2009 - 12:04
can back focus be fixed?
Lenses can definately be calibrated which was an option i had at the time from sigma.But i preferred to send it to srs.:wink: I wonder how though... I can't see the lens paying any "active" part in the focusing. The lens doesn't say if it is in focus or not it simply moves nothing more right? T...
Posted by Anvh on 12/07/2009 - 23:40
can back focus be fixed?
"SAFOX" stands for Sensor Ability Fortifying Optical Compensating System. It has gone through four revisions, with SAFOX-I being used in the SF series AF bodies, and SAFOX-IV being used in the ZX/MZ bodies. All SAFOX-type lenses are fully compatible with all SAFOX bodies. Basically, this means that ...
Posted by Anvh on 13/07/2009 - 00:06
can back focus be fixed?
Tolerances in manufacturing are inevitable - nothing in this world is 100% accurate at any price. However, you should expect that a lens will work fine on your camera body and usually they do. In cases where they don't, then recollimating the lens will no doubt put it right. The K20D goes a st...
Posted by johnriley on 13/07/2009 - 08:57
A golden oldie - Tamron 400mm f7.5
I closed my eyes, took a breath and then a big leap in the dark the other day and put a bid on a vintage (as in 1960's) Tamron 400mm f7.5 t-mount lens on Ebay. To my surprise I won it for only for only a little over £20. :shock: It arrived this morning. I must admit, I wasn't expecting too mu...
Posted by andrewk on 15/07/2009 - 14:27
Jack of all trades
I don't see anything inherently illogical here as we are discussing two entirely different lenses. Gwyn finds her Tamtron 28-300mm lens not up to scratch on the K20D but fine on lower resolution sensors. The implication is that the lens does not have sufficient resolution for the K20D sensor and ...
Posted by johnriley on 17/07/2009 - 15:05
Using DOF scales on old A series primes?
As some of you know I've just entered into using manual focus having just bought both a 50mm & 28mm A series lens. It would be nice to be able to use the DOF scales but I guess with the cropped sensor of the K20D this isn't going to work correctly. How to people tend to use these manual lenses, p...
Posted by simonkit on 19/07/2009 - 10:51
Using DOF scales on old A series primes?
Simon With an "A" lens you should leave it in the "A" position and use the camera wheel to set the aperture. You will not be able to use all the auto exposure settings otherwise. Also leave the lens on "A" all the time, it prevents any malfunction of the aperture ring. You can use the DOF scal...
Posted by pschlute on 19/07/2009 - 11:38
