Search results for 'sensor cleaning' - page 718
F stop / Aperture value?
The only time f-stop and aperture value are the same is at infinity. f-stop is the value of the focal length divided by the opening, but when you change the focus, the actual focal length changes somewhat, so the indicated opening and the aperture value are different. Whilst true for many lenses, n...
Posted by petrochemist on 26/12/2012 - 16:00
F stop / Aperture value?
Whilst true for many lenses, not all lenses change focal length. Some of mine, especially older primes, simply increase lens-sensor distance and have no way of altering the relative spacing of elements without taking them apart. ALL lenses change focal length a little bit while focusing. The increa...
Posted by pentaxian450 on 26/12/2012 - 17:59
F stop / Aperture value?
SO when you focus, the F stop remains physically fixed but the amount of light passing through it is actually either more or less than the fixed F stop value. You are about right. At infinity, the marking and the metering value are accurate. But when you focus closer, there is less light reaching...
Posted by pentaxian450 on 27/12/2012 - 01:46
A hello and a request for guidance
Greetings all. This is my first post and I'm already going to ask for help:oops::):) I currently own an Olympus E520 with 5 lenses ranging from 18mm up to 600mm (35mm equivalent), Olympus FL36 flash, Olympus remote, Giottos tripod and various Cokin filters. The lenses include standard and ED SW...
Posted by RalphHardwick on 29/12/2012 - 16:55
A hello and a request for guidance
Hi Ralph, You may have noticed my post over on the 'other' forum, having owned both systems there truly is a paradox if your favoured route is the zoom lens. Firstly there is no doubt that Pentax currently offer a superior D-SLR body, I was very fond of both my K20D and K7 bodies and I'm sure the ...
Posted by Greytop on 31/12/2012 - 12:26
K30 in bag, which is the best way to place it please?
My K-x was /is always packed with lens on and lens down BUT I make sure it's supported and there is a space under the end of the lens . This has the advantage of ensuring that any dust particles will fall away from the sensor and shutter mechanism, rather than towards. I agree that the lens shoul...
Posted by johnriley on 01/01/2013 - 21:14
K30 in bag, which is the best way to place it please?
I'm not confident about taking the lens on and off the body, someone told me I had to be careful about bending the pins if I did it wrong. So I keep lens on all the time. Sort of defeats the idea of a DSLR really, may as well buy a high end compact or bridge camera. Wouldn't worry about it .. h...
Posted by Smeggypants on 03/01/2013 - 02:37
still capture from home video - any good (Free?) downloads
VirtualDub, but stills from a video will most likely be terrible quality regardless of what tool you use; just the nature of the beast I'm afraid. Obviously quality will vary depending on whether it's been recorded at 24, 30 or 60fps, and on the true resolution and size of the sensor (which will ...
Posted by mdc on 03/01/2013 - 11:48
Astro Photography - Equitorial Mount
Hi As regards "how accurate is a Haig mount" it depends on how accurately you make it and (as with an equatorial mount) how accurately you polar align it, and finally how much magnification you are aiming for. I would think for exposures of 30 mins or more you'd be pushing it. However a cheaper (an...
Posted by PaulEvans on 08/01/2013 - 07:22
Pentax MX-1 Announced!
It's got a 1/1.7inch backlit CMOS sensor, so it's not built around the K-01 or Q but completely new.
Posted by joshwa on 07/01/2013 - 14:46
Pentax MX-1 Announced!
I suspect some co-operation with Olympus... The Olympus XZ2 has identical specs for both sensor and lens, but has a hotshoe and a control ring around the lens. However the lens/sensor combination gets well reviewed in the Olympus, so at least it is likely to be a competent performer!
Posted by amilner on 07/01/2013 - 15:09
Pentax MX-1 Announced!
I like it! I have spouted for years that Pentax needed a "pro-spec" compact camera that could rival the likes of Canons G series, Nikons P7xxx, Pano LX etc etc. If this was out 12 months ago I would have bought it instead of the LX-5. Then again, I love its looks, it has a decent sensor, not as big...
Posted by Offertonhatter on 07/01/2013 - 18:43
Pentax MX-1 Announced!
I,'ve been after a compact with a hotshoe for a while. The reason is that it's already got a small sensor so is poor in low light, so why hobble it even further by not allowing external flash? That's very much what they call a deal-breaker.
Posted by Jonathan-Mac on 07/01/2013 - 21:23
Pentax MX-1 Announced!
The reason is that it's already got a small sensor so is poor in low light Can we jump to that conclusion without seeing the results? The game is changing around us and, for example, the Q is much better than many may realise. This has a bigger sensor than the Q and similar sensors perform very well...
Posted by johnriley on 07/01/2013 - 21:39
Pentax MX-1 Announced!
The reason is that it's already got a small sensor so is poor in low light Can we jump to that conclusion without seeing the results? The game is changing around us and, for example, the Q is much better than many may realise. This has a bigger sensor than the Q and similar sensors perform very well...
Posted by Pentaxophile on 07/01/2013 - 22:50
Pentax MX-1 Announced!
Then a Q would be the better option. Personally I've never seen anyone use a compact with a whacking great flash. It seems that the Olympus XV-2 has the same sensor and the lens looks very similar. So that is a guide to the image quality. I'll stick with the Q (subject to a wide angle p...
Posted by DrOrloff on 08/01/2013 - 09:23
Pentax MX-1 Announced!
It looks pretty good to me! I am already considering it as a replacement for my Fuji X10 (which was stolen a few months ago), even though the sensor is a bit smaller. I suspect RAW files will be better from the Pentax due to the trouble most RAW converters have with Fuji's proprietary file type. The...
Posted by aliengrove on 08/01/2013 - 16:10
Enlarging photos to hang on the wall, what's the best size please?
16x12 is of course a 4:3 format and suits the 20x16 (500mm x 400mm) mount board standard if you desire a uniform width mount border. Personally I don't feel the need to print every sensor pixel and many photos benefit from cropping in one way or another, even if this results in a non standard for...
Posted by WaypointCharlie on 17/01/2013 - 16:53
photographing the moon
The correct base exposure for the Moon, with clear skies is 1/125th of a second at f8 at 100 ISO, it always is, even a crescent Moon is the same if you don't want to burn out the illuminated crescent. The light reflected off the Moon is a constant, it doesn't vary. Even if the Moon is only a small p...
Posted by screwdriver on 23/01/2013 - 14:43
Useful site for camera/lens/filter size comparisons
Came across this site the other day whilst considering various compact and compact system cameras and wondering how the size compared with my K-30. No substitute for actually handling them, but with the demise of Jessops that's not as easy as it was. You can compare camera bodies only from a number ...
Posted by milamber on 21/01/2013 - 15:44
