Search results for 'sensor cleaning' - page 136
Samyang 24mm f1.4
Probably right John as far as Pentax DSLR's are concerned. The other three players don't need to. Maybe better to use FOV as it covers all sensor sizes. This is indeed an old chestnut. The idea of replacing focal length with field of view has been mooted for decades. It's not without merit, but unfo...
Posted by johnriley on 13/08/2011 - 14:00
Samyang 24mm f1.4
The theory of this is that we forget all about focal lengths and only use the field of view. In this way, it doesn't matter what size the format is. So, if we have a camera with a 47 degree lens (not 46 degrees, I've looked it up now)it happens to be a 50mm lens on 35mm film, but that is no longe...
Posted by petrochemist on 13/08/2011 - 18:58
Samyang 24mm f1.4
I would definitely recommend the 21mm Pentax as a better "journalist and landscape" lens, though it is slightly slower, it has AF. Best regards You are off-setting AF/Ltd appeal vs. MF/speed/price. It's a decision that many will ponder. FWIW when you get to these FLs then AF is not absolutely ne...
Posted by K10D on 14/08/2011 - 15:13
My disaster/nightmare lens story...
The only lens I keep a filter on is my DA 55-300, and that is literally just to keep the dust off it! I posted a thread a few months ago when I first got the lens about how the front element attracts dust like a magnet. Everybody seemed to think that was a bit strange at the time. Well, strange as i...
Posted by MarkTaylor on 15/08/2011 - 18:24
yashica to pk converter
Sad to say I doubt they exist, at least for sensible money and without glass which tends to degrade image quality. The only adapters I see are for the M42 screw mount lenses, as this mount is small enough to fit inside the K mount and therefore allows an adapter which won't affect the distance fr...
Posted by Dangermouse on 13/08/2011 - 21:22
50mm Lens for my K-r
Are you after a 50mm or the equivalent of a 50mm? Thanks to the DSLR sensor being smaller than a film frame the field of view of a lens has changed. 35mm on a Pentax DSLR is roughly equivalent to a 50mm lens on film, and there are two excellent lenses of that focal length depending on your budget...
Posted by Dangermouse on 17/08/2011 - 20:04
Sigma macro for K-x
I presume you mean this, Trixie: Providing it is the K-mount version, it will work with your K-x (Av mode) focussing will be entirely manual: not necessarily a bad thing but something you need to be aware of. If the crop factor of the K-x sensor is taken into account (approximately 1.5x), it wi...
Posted by prsjnb on 19/08/2011 - 11:25
Sigma macro for K-x
I presume you mean this, Trixie: Providing it is the K-mount version, it will work with your K-x (Av mode) focussing will be entirely manual: not necessarily a bad thing but something you need to be aware of. If the crop factor of the K-x sensor is taken into account (approximately 1.5x), it wi...
Posted by trixie on 19/08/2011 - 17:45
An open Letter to Ricoh
And 55-200 has become the 'classic focal length' for a second kit lens on ASP-C. No surprise people upgrading from kit lenses look for something with a similar range. The Sigma and Tamron 70-200s F/2.8s are popular for a reason too and the fact that the 60-250 is an F/4 does make a difference. Penta...
Posted by Anvh on 20/08/2011 - 10:34
An open Letter to Ricoh
And 55-200 has become the 'classic focal length' for a second kit lens on ASP-C. No surprise people upgrading from kit lenses look for something with a similar range. The Sigma and Tamron 70-200s F/2.8s are popular for a reason too and the fact that the 60-250 is an F/4 does make a difference. Penta...
Posted by MarkTaylor on 20/08/2011 - 17:47
An open Letter to Ricoh
I think Mark Taylor has a point, it's time we stopped using the 35mm equivalent in describing lenses. This won't happen due to the profusion of older lenses designed for full frame. Not to mention the camera systems in which one can interchange lenses built for different films/sensors (like Pentax)....
Posted by MarkTaylor on 21/08/2011 - 00:52
An open Letter to Ricoh
So it maybe better to use "Full Frame" as the reference phrase and always include "field of view" in the statement. Oh no please don't use full-frame... Full frame means you use the full frame of a standard size and since APS-C is a standard size you can say they are full frame as well. Also FOV...
Posted by Anvh on 21/08/2011 - 11:20
An open Letter to Ricoh
Well no Anvh, full frame in dslr terms is accepted to mean (oddly enough) a sensor the same size as a 35mm negative 36x24mm. The term Full Frame originated (I think) in the film business where it meant using the full 35mm frame in filming. I'm confused about how field of view can be affected by...
Posted by Steep on 21/08/2011 - 11:49
An open Letter to Ricoh
You might be right... but i find it strange that the 645D for example has a crop sensor while it's larger then 135formatt, how can it be a crop while it's larger? :? It's not that hard to explain, you just have a different meaning in mind, not something worth a new topic i believe. I'll just p...
Posted by Anvh on 21/08/2011 - 12:17
An open Letter to Ricoh
You might be right... but i find it strange that the 645D for example has a crop sensor while it's larger then 135formatt, how can it be a crop while it's larger? :? It's not that hard to explain, you just have a different meaning in mind, not something worth a new topic i believe. I'll just p...
Posted by MarkTaylor on 21/08/2011 - 14:34
An open Letter to Ricoh
The 645D's sensor is not a crop sensor, it is a "medium format" sensor. Although it still technically has a "crop factor" (albeit of less than 1 because it's larger than 35mm film) this can more correctly be referred to as a "focal length multiplier" to avoid the confusion - or alternatively for any...
Posted by K10D on 21/08/2011 - 19:39
An open Letter to Ricoh
The 645D's sensor is not a crop sensor, it is a "medium format" sensor. Although it still technically has a "crop factor" (albeit of less than 1 because it's larger than 35mm film) this can more correctly be referred to as a "focal length multiplier" to avoid the confusion - or alternatively for any...
Posted by MarkTaylor on 21/08/2011 - 20:11
An open Letter to Ricoh
[quote:3496ace15f="MarkTaylor"]The 645D's sensor is not a crop sensor, it is a "medium format" sensor. Although it still technically has a "crop factor" (albeit of less than 1 because it's larger than 35mm film) this can more correctly be referred to as a "focal length multiplier" to avoid the confu...
Posted by K10D on 21/08/2011 - 21:22
An open Letter to Ricoh
So Pentax may be technically incorrect to use the term MF Indeed, but then language has a nasty little habit of being defined by usage and not by what is technically correct. I'm quite sure a Victorian English teacher would have to send us all to the bottom of the class for a variety of misdemeanors...
Posted by MarkTaylor on 21/08/2011 - 21:46
An open Letter to Ricoh
The FF DSLR users I know use the term the same way as everybody else. MF users do use the term crop sensor for sensors that are in the 645D for example and use the term full frame for a sensor that is the full size of a 645. Just look on some forms where a lot of MF users are, luminous landscape ...
Posted by Anvh on 22/08/2011 - 10:00
