Dave Peters

Dave Peters

Lives in United Kingdom Bristol, United Kingdom
Works as a Engineer
Has a website at www.dpsoftware.com
Joined on Feb 23, 2006
About me:

Canon 1Ds MkIII, 5DmkII, 30D, 450D, 10-22, 50 f1.4, 100 macro, 70-200 f4 IS, 100-400L, EF800 f5.6, Sigma 300-800, Sigma+Canon 1.4x, 500D closeup, Kenko tubes, 580EX flash.
Minolta 7D, 50,100,200mm macros, 70-210 f4, Tokina 300 2.8, Kenko pro300 1.4x and 2x, 5600HS flash, flash extender
Gitzo 1548, 3541LS Wimberley Mk II, Mongoose M3.5a

Comments

Total: 17, showing: 1 – 17
On Tamron to develop 150-600mm F5-6.3 ultra-telephoto zoom news story (193 comments in total)
In reply to:

pellinger: How will this compare (on a Canon) to a Canon 100-400 f/4 with a 1.4x tele-convertor? Seems quite a lot bigger and heavier for a very similar spec, or am I missing something?

The Canon 100-400 is f5.6 at 400 so with a 1.4x it becomes f8. Compared to the Canon 200-400 f4 with built-in 1.4x its a lot lighter and only slightly slower. Will be interesting to see what the quality is like.

Direct link | Posted on Nov 7, 2013 at 10:15 UTC
In reply to:

DanCee: just a thought.. this dual pixel, apart from helping AF in live/movie mode.. Canon might use this method to improve sensitivity/DR?? A 40MP sensor in disguise?? .. just curious about the IQ

The only way phase detect AF will work is if each pixel half only receives light from one side of the lens so it must be masked and part of the exposure. By reading out the combined half pixels for the main image, you get the combination of both halves of the lens.

Since for in focus images you expect the same from both sides, there is no reason you could not use your increased dynamic range technique. Not sure what will happen in out of focus areas though - might be some strange effects.

Another interesting idea might be to readout the images separately and use some sort of mask over the front of the lens to obtain stereo pairs for 3D imaging.

Direct link | Posted on Jul 3, 2013 at 15:00 UTC
In reply to:

DanCee: just a thought.. this dual pixel, apart from helping AF in live/movie mode.. Canon might use this method to improve sensitivity/DR?? A 40MP sensor in disguise?? .. just curious about the IQ

Each half of the pixel is already getting half the total exposure as it only gets light from half the lens. Its only the readout that changes. If the image is in focus then you should have half the charge in each of the pixel halves. So dynamic range would not be affected for an in focus image and reading out charge from both halves simultaneously just gives you back the same signal to noise that you would have had as a single pixel.

Direct link | Posted on Jul 2, 2013 at 12:05 UTC
In reply to:

oysso: why not give a general support for AF at F8 in center point as the previous 1D line cameras?

The 1Ds MkIII does have general f8 at center point already so there must be something strange about the way this lens reports to the camera if it needs a firmware mod.

Direct link | Posted on May 30, 2013 at 15:00 UTC
In reply to:

RPJG: "the new EF 200-400mm F4 L IS 1.4x lens ... when it is used with an extender ... the combined aperture is F8"

Shouldn't f/4 with a 1.4x extender give a combined aperture of f/5.6?

I think thats f4 plus in-built extender taking it to f5.6 plus external 1.4x taking it to f8.

Direct link | Posted on May 30, 2013 at 13:58 UTC
In reply to:

erbtype: The price is the price and will fall over time as these things do, but £12k UK = a lot more than Euro 11.8K, so basically Canon are saying buy from a Euro shop if you live in the UK or someone fluffed the press release.

Most likely the Euro price is excluding tax as the rate will vary depending on country and the UK price includes 20% VAT which is fixed. This makes it about the same price. However its still loads cheaper from the USA even taking into account tax and delivery. So as usual European dealers lose my custom due to Canon Europes' ridiculous pricing. I just pre-ordered from B&H. Of course you are right, the price will fall here eventually - but how many UK companies are going to stock it ?

Direct link | Posted on May 14, 2013 at 11:17 UTC
In reply to:

Mike Wee: How exactly does attaching a piece of electronics to the bottom of the camera get around the need for hacking the firmware?

People resort to firmware hacks because manufacturers do not provide API's to the firmware, not because they don't have a Rasp. Pi in the grip.

There is no Canon software for Linux but he is using GPhoto which is a hack of the USB protocol. The advantage of using Linux is that you have low cost and lower power. The disadvantage is that you have to use the hack which doesn't have full functionality and may not work immediately with new cameras.

If you use Windows then you have higher power, needing special consideration for heat and much higher cost. However you can use the standard Canon toolkit which is normally available with new cameras and has a lot of functionality.

Direct link | Posted on Aug 16, 2012 at 22:12 UTC
In reply to:

BJL: Where is this f/5.6 lens more useful than options like
- 500/4 or 600/4 with 1.4x TC, giving 700/5.6 and 840/5.6
- 400/2.8 with 2x TC, for 800/5.6
- those 500 or 600 f/4 lenses on a DX camera, at half the ISO speed due to being one stop faster than this f/5.6 lens
- 400/2.8 + 1.4x TC on DX format, for 560/4 and again needing only half the ISO speed of this f/5.6 lens.

All those alternatives probably save money, and are more flexible with their options of somewhat wider angle of coverage when 800mm is too extremely narrow.

The only answer I see is that Nikon no longer makes a high end, high frame rate, highly rugger pro style body in DX format.

I dont know a lot about the Nikon system but with the Canon, there is a focus speed penalty with the converters. The other thing is that once you get above 1.4x the image penalty is great (with 2x or stacked 1.4x). So with 800mm you can get excellent 1120mm with the 1.4x but with 600mm your maximum with great image quality is 840mm. The latest Canon bodies cant focus at f8 though so I would no longer consider their 800 over the 600 (if I didnt already have the 800). This new Nikon gives me a possible option to switch from Canon in the future if there is no suitable body when I want to upgrade.

Direct link | Posted on Aug 7, 2012 at 11:30 UTC
In reply to:

Ramjager: Well apart from being 4 years behind the competition it looks nice..

Well its a bit later than the Canon but at least Nikon have current f8 focus bodies whilst Canon have abandoned them. If you can't AF at f8 then you may as well have a 600 f4 and 1.4x and gain flexibility. Also dont forget that Canon are behind Nikon with the 200-400 f4 so its swings and roundabouts really.

Direct link | Posted on Aug 5, 2012 at 10:07 UTC
On Lightroom 4 Review article (480 comments in total)
In reply to:

Dave Peters: Not compatible with Lightroom 3 ? So I can't load my existing catalogues and even if I re-import the photos to a new catalogue they will appear different and require reprocessing. I think forward compatibility is an essential feature. They should have kept all the old processing routines so that the program could detect old files and show the images correctly.

Thank you all for the information, thats great news - I will upgrade.

Direct link | Posted on Mar 6, 2012 at 21:18 UTC
On Lightroom 4 Review article (480 comments in total)
In reply to:

Dave Peters: Not compatible with Lightroom 3 ? So I can't load my existing catalogues and even if I re-import the photos to a new catalogue they will appear different and require reprocessing. I think forward compatibility is an essential feature. They should have kept all the old processing routines so that the program could detect old files and show the images correctly.

Thanks, thats good to a point but if I used controls that are no longer available then I assume my photos look different in version 4 to they did when I processed them in V3. I don't want to have to check every image when I want to re-export at a differeent resolution and have a customer complain it doesn't match the sample. So I would have to keep separate V3 and V4 catalogs and lose the ability to search across them or reprocess every image, update samples, website etc. Much more likely to stay with V3.

Direct link | Posted on Mar 6, 2012 at 12:37 UTC
On Lightroom 4 Review article (480 comments in total)

Not compatible with Lightroom 3 ? So I can't load my existing catalogues and even if I re-import the photos to a new catalogue they will appear different and require reprocessing. I think forward compatibility is an essential feature. They should have kept all the old processing routines so that the program could detect old files and show the images correctly.

Direct link | Posted on Mar 6, 2012 at 09:25 UTC as 123rd comment | 5 replies
In reply to:

Michael J Davis: I've now read the PR and specs three times, and can find no reference to the lenses (other than independent use)!

No fl or aperture? Does it means they are fixed with digital zoom or what?

Did I miss something?

Mike

Robert gave you the correct reply, it's 25-100 equivalent. Here is shortened link to more info:
www.sendme2.com/pan3d

Direct link | Posted on Nov 7, 2011 at 13:43 UTC
In reply to:

Michael J Davis: I've now read the PR and specs three times, and can find no reference to the lenses (other than independent use)!

No fl or aperture? Does it means they are fixed with digital zoom or what?

Did I miss something?

Mike

Press release states 25mm ultra wide angle with 4x optical zoom. Not sure if that means 6.25mm - 25mm

Direct link | Posted on Nov 7, 2011 at 13:33 UTC
On Canon EOS-1D X professional DSLR announcement and overview news story (524 comments in total)
In reply to:

Dave Peters: No AF point for f8 lenses ?
Who needs 12 fps if you have to use mirror lockup to use it ?
Nice to see 2 x CF slots and option for GPS
Need to wait and see how AF tracking is improved
Is the battery the same as mk III and IV ?

You are right it was 14 fps that needs mirror lockup - sorry.
I have the Canon 800mm f5.6 which becomes f8 with 1.4x extender. The 1Ds mk III will AF with it so if this doesn't its a serious limitation for me.

Direct link | Posted on Oct 18, 2011 at 10:46 UTC
On Canon EOS-1D X professional DSLR announcement and overview news story (524 comments in total)

No AF point for f8 lenses ?
Who needs 12 fps if you have to use mirror lockup to use it ?
Nice to see 2 x CF slots and option for GPS
Need to wait and see how AF tracking is improved
Is the battery the same as mk III and IV ?

Direct link | Posted on Oct 18, 2011 at 09:05 UTC as 123rd comment | 5 replies
On Corel launches PaintShop Pro X4 image processing software news story (37 comments in total)

Beware download versions of software from Corel. I bought Coreldraw and now I have made more changes to my machine than they allow, the software will not work unless I reconfigure to one of the previously seen configurations (different 2nd hard disk). They will not re-enable my software without a further purchase even though I am still using the same machine. I haven't even changed the drive that the software is installed on. I will never be purchasing any more software from them.

Direct link | Posted on Sep 9, 2011 at 14:44 UTC as 13th comment | 1 reply
Total: 17, showing: 1 – 17