I've just tried the maths on this:

Full Frame sensor size = 36mm x 24mm = 864 sq mm
APS-C (K-5) Sensor size= 23.7mm x 15.7mm = 372 sq mm
So with a bit of algebra

X =
372 x 24 = 10.4 MP
864

Where X = the MP component of a 24 MP sensor

Of course, though, a sensor can be made to give other resolutions to this they are usually only lower!

At best if the crop was to exactly half frame size (24mm x 18mm) the resolution would be 24 / 2 = 12 MP.

If someone can prove the APS-C component of a 24 MP sensor could be 16MP then I'll be curious to see that calculation!

John

Please post any comments, queries or complaints regarding the competition in this thread and leave the other one purely for the entries. Thanks.

John

I've tried to come up with a theme that allows for quite a range of subject matters so folk aren't frightened off by the subject. What I'll be looking for is a photograph showing something of our heritage, i.e. something inherited from the past. It could be something natural, cultural or traditional for instance (not limited to these examples.) This doesn't necessarily mean UK heritage either, it can be from anywhere.

The usual rules apply for this Fortnightly Competition. Entries close 18.00 BST. 4th July 2012. (Independence Day I presume!)

Please remember the EXIF data!

Will this be the last of the fortnightly comps in this format before changing to the new monthly format in the gallery? If so let's let it bow out with a bumper crop of entries this time so thanks in advance for yours.

Good luck,

John

Well thanks. There weren't too many entries this time. I think some might be frightened of processing pictures or maybe not have software to do it, or think the software they have can't do it. I think its congratulations to everyone for having a try this time so well done milamber, sandinista and bforbes in particular, but they were all good though. I guess I struck lucky having a suitable subject to go and photograph; I thought of that image almost right away but had to get the timing right to go and take it. Anyhow thanks for setting an interesting theme for those that liked the challenge and judging it with such positive comments.

I liked waypointcharlie's texture so much last night that I thought it would make an ideal 'grunge' picture to go with a photo I took on Monday on our Olympic flame day!
Hope you (wp) don't mind me sharing it - let me know if you do and I'll delete it.




It's the predominance of the blues and yellows that made me think of it.

I'll set up the next comp threads shortly and have thought that the theme 'Heritage' might be accessible to most users so hopefully it will attract more entries. We'll have to see.

John

I'd wondered about those too. Seen this? link
(I'm sure they could have come up with a better name for their site!) That's not very encouraging.

eBay #320841271957 is a C mount lens complete with Pentax Q adapter. I was wondering if it might be worth a punt.

One thing in the C mount lens's favour is that they appear to have some form of aperture control but if they are optical disasters there may not be much point.

John

Harbour Scene




EXIF:
Camera Model: SAMSUNG GX20
Lens: PENTAX DA 18-55mm AL WR
Image Date: 2012-06-16 19:47:43
Focal Length: 21.3mm
Aperture: f/8.0
Exposure Time: 0.0080 s (1/125)
ISO equiv: 200
Orientation: Normal
Software: Adobe Photoshop Elements 6.0 Windows

Image consists of three layers:
Original raw file converted to black and white;
A sepia filter layer;
Texture layer (credit to Wood_CXXXXXIV_by_aqueous_sun_textures.jpg)

John

Just updated the camera firmware to 1.01 now. It only took a few seconds, the K-5 update took quite a while if I remember correctly.

According to DPR there are lens firmware updates too to 1.01. Never had to do that before.

John

Sussed it out. The battery was upside down!!

Hope OK now. Thanks,

John

Thanks John, the lever is there however it doesn't hold the battery in place at all, the battery slides right past it. The camera works fine when the main battery cover is closed, but I would think that to remove the battery after opening the cover that lever should require pushing back. But it doesn't and it isn't holding the battery in place at all.

Sounds like it is faulty.

John

Thanks, but no it doesn't. You're implying that it should do?

John