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Messages - jthomson

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Lenses / Re: Telephoto for 6D?
« on: August 18, 2013, 07:56:13 AM »
You should take a look at the Tamron 300mm USD VC.  It is in your price range.

Animal Kingdom / Re: Show your Bird Portraits
« on: August 18, 2013, 07:50:49 AM »
A couple from the last few days

don't have your specific equipment, but  I've used a kenko 300 dgx 1.4x converter on a 5D3 with  my 400mm f5.6L with no problems.  Before and after the firmware upgrade.

I am a little confused.  The Digital Picture review claims that this new S version shows a significant improvement in sharpness, and has the comparative test results to back this up.  Yet the MTF charts and optical design for this lens and the previous version are  identical.  Also, Roger over at LensRentals (who I have a great deal of faith in) says: "the optics are identical" and consequently he wouldn't pay the extra grand for the new version.

What do you think is going on here?

Explained in article.

 Roger, after tearing down both OS versions of the 120-300, said it appeared that elements in these lenses could be interchanged. The optical design seems unchanged. When questioned about this, Sigma replied that the 120-300 "S" has 2 FLD Glass elements instead of one. FLD glass has performance equal to fluorite, which is excellent.

So 2 FLD elements instead of one so better IQ.

Lenses / Re: Cheap telephoto lens
« on: July 17, 2013, 04:36:29 PM »
Which one to choose? The cheaper Tamron or the Canon with the better optics?

Actually the Tamron  is cheaper and has better  optics than the Canon 70-300mm.
 See the Photozone  review. http://www.photozone.de/canon-eos/592-tamron70300f456vceosapsc?start=1
Its a no brainer get the Tamron 70-300mm USD VC.

Lenses / Re: Dxo tests canon/nikon/sony 500mm's
« on: July 15, 2013, 11:17:55 AM »

The most important factor in their BS Score is transmission, which is why the cheap 50/1.8 lenses from both Canon and Nikon score several points higher than any of these 500/4 lenses. It's only when you have lenses of identical max aperture that the other stuff has any influence.  BTW, while the 500/4s score 25, the Canon 50/1.8 on a 5DIII gets 28, and the Nikon 50/1.8 on a D800 gets a 31, and main measurement difference between the 50/1.8s is that the Nikon is 1 P-Mpix sharper (put it on the D3X, it's sharpness and Score tie the Canon). So, the Nikon 50/1.8 is 1 P-Mpix sharper and gets a Score 3 points higher, the Canon 500/4 is 3 P-Mpix sharper, but the Scores are equal.


I begin to wonder if the 'secret metric' you mention is sponsorship...   :o

If transmission really was the most important factor then the Sony should  be out scoring the Nikon.  The Sony equals or beats the Nikon in all the listed categories and has  the lowest transmission of the three lenses.

Basically I think DxO are a bunch of Nikon fanboys.  The individual ratings are fine, but the composite scores ae just ridiculous.

Software & Accessories / Re: Lightroom vs. DPP
« on: July 05, 2013, 11:04:02 AM »
I've been using DPP for years.  Decided to try out LR.  Didn't like it.  Even opening the RAW file showed me huge differences immediately (shot in "faithful" with sharpening at 0 from the camera).  Add to that the complexity of using LR and I quickly went back to DPP.

That's because DPP applies "faithful" when you import.  By default LR applies Adobe Standard.  You need to set up an import preset in Lightroom to apply the camera calibration "faithful" on import. 
I expect that this is also what the OP was seeing when he talks about the original RAW's .

Third Party Manufacturers / Re: Canon 300 2.8 IS II with Gimbal Head
« on: June 27, 2013, 10:32:18 AM »
naturescapes has a replacement foot that allows you to adjust  how much of the plate sticks forward and backward. 


Lenses / Re: The ULTIMATE Canon lens
« on: June 25, 2013, 11:26:15 AM »
The Canon-made “Wide Field Corrector,” as it’s called, is placed in front of the giant sensor in order to improve the image quality of the main telescope lens.

So it is really just the worlds largest extender. ;)

« on: June 19, 2013, 12:35:27 PM »
Here are some general guidelines about who owns copyright on photographs and illustrations in the absence of written agreements to the contrary. When photographers/illustrators create photos, portraits or engravings (in the case of illustrators, portraits only):
 ◦When creators produce a work for themselves, they own the copyright.
 ◦When creators produce a work as part of their employment, including apprenticeships, the employer owns the copyright.
 ◦When created on a commissioned basis, the person or company that commissions the work owns the copyright once they have paid for it in full. If the client who commissions the work fails to pay for it, the copyright remains with the creator.

This is based on canadian copyright law.  The company is correct, they own the rights to what they commissioned unless  you have a contract that explicitly states that the photographer retains the rights.
You should look at gettng some standard contract documents  that allow  you to retain your rights. 

Just googled some more and apparently this was changed late last year.

General Copyright information: Photographs
At Last, Canadian Photographers Own Their Copyright.
The Professional Photographers of Canada (PPOC) and the Canadian Association of Professional Image Creators (CAPIC) would like to congratulate all photographers in Canada on this important date and pivotal achievement in the photographic industry. As of Nov 7, 2012, Canadian photographers officially own the copyright to all of their work whether the photograph is commissioned or not, thanks to the new Copyright law.

3rd party grip and batteries. Genuine Canon products are way over priced.
I've never had a problem with the 3rd party batteries and grip on the T1i for the last three years. Have had 3rd party grip and batteries on the 5D3 for about 6 mo with no problems until the firmware change.  Now the batteries don't register with the camera, but haven't seen any perfomance issues, the charge indication still works.


Lenses / Re: Why Does the 100-400L Sell So Well Still ?
« on: June 06, 2013, 11:20:33 AM »
The 100-400mm L sells well because it and the 400 mm f5.L are the only  semi-affordable 400mm  lenses with decent image quality.   The 100-400mm L sells better than the 400mm f5.6L because the zoom is more versatile than the prime.

The 70-300mm L doesn't sell as well because it is overpriced.  You don't need to spend  $1400 to get a 70-300mm lens. Canon makes a non-L 70-300mm that many people get as their first long telephoto and Tamron makes a 70-300mm  that is  both less expensive and better than the Canon Non-L.  If you have either of these lenses  and you want to upgrade, then you will most probably pick one of the 400mm's  to get the better image quality and the extra 100mm  than   for  the 70-300mm L that has only a small improvement in image quality.

This will probably change when Canon finally upgades the 100-400mm.  I would expect that the price will go up to around $3500 and then the 70-300mm L  will look more attractive. 


Reviews / Re: what utter crap this is.... samyang 24mm TS
« on: June 03, 2013, 05:56:07 PM »
Well I bought the lens and am quite happy with it.  It makes the verticals vertical, and generally I need it to be at f8 to f11 to get a large DOF.
I'm frequently photographing structures like below in poor light conditions.  The Samyang works just fine.
The data on Lensrentals clearly  show that at f11 and above the resolution of the Samyang is equal to the Canon.  Yes it would be nice if it was better  below f8, but why make such a big deal about it? Its not the first lens that needs to be stopped down to get decent resolution, and it won't be the last. 

Lenses / Re: Do you wish your 70-200L were black?
« on: May 22, 2013, 05:50:50 PM »
The relationship between colour and temperature of bodies receiving radiation is not as straightforward as 99% of postings on the net say. Although black absorbs heat better than white, it correspondingly radiates heat better. The inescapable consequence is that black and white bodies reach the same temperature when they are in sunlight but black gets there faster.  Conversely, the black body will cool down faster when taken out of sunlight.  So, the Nikon lens heats up faster than the Canon L, but both eventually reach the same temperature and the Nikon cools down faster.

While not as straight forward as some postings would indicate, the basic fact that a typical flat black object will reach a higher temperature  in the sun that a typical white painted object is correct.  The black traps more of the suns energy, the white reflects it.  That is why things like propane tanks are painted white.  You can verify this yourself on a sunny day.  Put one hand on some ashphalt surface and the other  on same grass alongside it.  The asphalt will be much hotter than the grass, guaranteed.

Lenses / Re: When is the New 100-400 Coming?
« on: May 16, 2013, 05:10:37 PM »

1. (less likely) The release of a new 100-400 will take some time after all because there's no immediate market pressure

2. (more likely) The new 100-400 will be much more expensive, i.e. generating more profit for Canon, and will be an "upgrade" to the existing lens rather than a replacement on the same level - more like 24-70 mk1 to mk2.

1. There is no market pressure, nobody makes a better lens in the size/price range.  That's why Canon hasn't changed the 100-400mm and the 400mm f5.6.

2.  New price will be similar to Nikon 80-400mm, probably something like $500 more.

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