Frank_BR

Frank_BR

Lives in Brazil Campinas/SP, Brazil
Works as a Engineer
Joined on Jan 20, 2005

Comments

Total: 250, showing: 1 – 20
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These superzoom cameras are especially interesting for macro and super-telephoto photography. The current 1/2.3" sensors are very good, and certainly better than the sensor used in an iPhone 6, for example. The quality of the pictures produced by a 1/2.3" sensor is not spectacular like a digital FF camera, but it rivals the best 35 mm photographic films from 20 years ago. I think the superzoom cameras are unfairly undervalued.

Direct link | Posted on Mar 2, 2015 at 22:24 UTC as 7th comment
In reply to:

Rich1939: 2000 mm will sell the hell out of this and the resultant atmosphere distorted images will disappoint the hell out of the buyers.

2000 mm can be very useful for shooting birds and small animals at short and medium distances, for which the effect of the atmosphere is negligible.

Direct link | Posted on Mar 2, 2015 at 22:04 UTC
In reply to:

AlexisH: Interesting approach. Hydrophilic rather than hydrophobic.

The filter is hydrophilic because most lenses are hydrophobic. :-)

Direct link | Posted on Feb 26, 2015 at 21:47 UTC
In reply to:

Frank_BR: Wouldn't a deep plastic hood be simpler, cheaper, more effective?

Yes, it applies if the hood is made large enough and the lens is not an ultra wide-angle.

Protecting ultra wide-angle and fisheye lenses from raindrops is an almost insoluble problem. By the way, the "Tokina solution" would probably produce vignetting with these types of lens. Besides, surely you know that the wide angle lenses are especially efficient to reveal specks of dust, dirt, scratches, etc. on the surface of the front lens or filter. Because the raindrops falling on the Tokina hydrophilic filter do not spread immediately for physical reasons, I expect that raindrops will be visible if the lens is under constant rain.

Direct link | Posted on Feb 26, 2015 at 21:34 UTC

Wouldn't a deep plastic hood be simpler, cheaper, more effective?

Direct link | Posted on Feb 26, 2015 at 20:50 UTC as 12th comment | 5 replies
On 45 24mm-Rishi-03-F2.8 photo in dpreview review samples's photo gallery (3 comments in total)

Yes, there is some coma but of low intensity, what makes this lens a good candidate for astrophotography.

Direct link | Posted on Feb 25, 2015 at 21:29 UTC as 2nd comment
On 25 Dan_2282_15mm_f5.6 photo in dpreview review samples's photo gallery (1 comment in total)

Stunning image quality. The ultra wide-angle zoom lenses definitely caught up with fixed focal length lenses.

Direct link | Posted on Feb 25, 2015 at 21:04 UTC as 1st comment
On 11 Dan_2526_15mm_f2.8 photo in dpreview review samples's photo gallery (1 comment in total)

To my eyes, the left edge is a little softer than the right. Possibly there is a small decentring, or the mounting is slightly tilted. In practice this difference in sharpness for wide open may be negligible, especially if the aperture is closed one or two stops.

Direct link | Posted on Feb 25, 2015 at 20:40 UTC as 1st comment

Those guys seem to believe in "Build a better mousetrap, and the world will beat a path to your door".

If they really think they have a good idea, it would be much simpler to sell this idea to Leica than trying to design a camera from scratch.

Direct link | Posted on Feb 25, 2015 at 01:59 UTC as 83rd comment | 6 replies
On More things we found cut in half (CP+ 2015 edition) article (140 comments in total)
In reply to:

TwoMetreBill: "Here's the buttock-clenchingly expensive Zeiss Otus 85mm f/1.4 Apo Planar T* ZE - a $4500 lens - brutally converted into a $2250 42.5mm. Shame."

Cutting the lens in half doesn't change the focal length. Otherwise an interesting article.

Yes, cutting in half a lens does not change the focal length, but the effective aperture is reduced by 1 stop. On the other hand, if you do a good job of cutting, you will have at the end TWO Otus 85mm F2 lenses!

Direct link | Posted on Feb 15, 2015 at 18:23 UTC
On CP+ 2015: Canon shows 11-24mm in cross-section article (63 comments in total)

Interesting. They cut in half only the mechanical and electrical parts. The optical elements themselves were intact. Probably they were reused and are now in a lens that will be sold to someone else.

Direct link | Posted on Feb 14, 2015 at 13:09 UTC as 4th comment | 2 replies
On CP+ 2015: Canon shows 11-24mm in cross-section article (63 comments in total)
In reply to:

CanonKen: I'd love a defective front element as a paperweight.

No problem. The front lens is negative.

Direct link | Posted on Feb 13, 2015 at 21:14 UTC
On Sigma24mmF1.4_samples-13-F1.4 photo in dpreview review samples's photo gallery (4 comments in total)

Wide open the center is very sharp but distant subjects at the upper corners are soft. On the other hand, near subjects at the bottom corners are sharp!. This apparently bizarre behavior is common in many wide-angle lenses, and the explanation is in the field curvature.

After F5.6 the performance in the corners is spectacular. The lateral chromatic aberration that plagues many wide angle lenses is almost nonexistent.

Direct link | Posted on Feb 13, 2015 at 16:14 UTC as 1st comment
On CP+ 2015: Canon shows off prototype 120MP CMOS sensor article (255 comments in total)

Many good lenses produce details in the center of the field which can only be revealed by a sensor resolution from 200 to 500 MP. Therefore, the increase in sensor resolution is most welcome. Many people who use the argument of diffraction against increasing sensor resolution forget that the impact of diffraction is gradual, and much of the falling of the response can be compensated via digital processing.

Direct link | Posted on Feb 13, 2015 at 14:59 UTC as 49th comment | 4 replies

Do not worry. Many babies are ugly at birth, too.

Direct link | Posted on Feb 12, 2015 at 19:58 UTC as 70th comment

"We shot these images with an eye to demonstrating the following:
•Sharpness at F1.4 across the frame" (DPR)
---------------------------------------------------------------------------------

Thank you for the photos. However, to evaluate the performance at F1.4 across the frame you should shoot a plane subject (or a subject at infinity). Unfortunately, all photos are of 3D subjects. Nonetheless, this Sigma appears to be an exceptionally good lens.

Direct link | Posted on Feb 12, 2015 at 12:18 UTC as 47th comment
In reply to:

Frank_BR: Nikon words: "While not recommended for general photography, the D810A is ..."

At a time when DSLR sales are falling rapidly, perhaps Nikon should focus on cameras for general photography, and not on special solutions for a small niche market.

Someone told me that an experienced engineer costs for a company at least $500,000/year in salaries, facilities, equipment, tools, etc. So even seemingly small changes in a product can represent significant costs for the company. In the case of D810A, Nikon had to use a special IR filter and a specific assembly line, but most of the additional cost probably came from the development of a new firmware, and the tests that had to be made before launching the camera on the market.

Direct link | Posted on Feb 10, 2015 at 17:42 UTC
In reply to:

Frank_BR: Nikon words: "While not recommended for general photography, the D810A is ..."

At a time when DSLR sales are falling rapidly, perhaps Nikon should focus on cameras for general photography, and not on special solutions for a small niche market.

The problem is that introducing products for niche markets always involves a significant development cost. Instead, Nikon could have worked on a version of the D810 with a fully articulated LCD. Maybe Nikon has concerns about the reliability of an articulated LCD in a professional camera. However, Sony has its professional camera A99 since 2012 and I have no knowledge about reliability issues related to the A99's fully articulated LCD.

Direct link | Posted on Feb 10, 2015 at 13:05 UTC
In reply to:

Frank_BR: Nikon words: "While not recommended for general photography, the D810A is ..."

At a time when DSLR sales are falling rapidly, perhaps Nikon should focus on cameras for general photography, and not on special solutions for a small niche market.

There is a lot of information out there about the drop in sales of DSLRs. View this Thom Hogan's article comparing shipments in 2012, 2013 and 2014:
http://www.dslrbodies.com/newsviews/the-numbers-are-in.html

DSLR sales in 2014 were approximately 2/3 of 2012.

Direct link | Posted on Feb 10, 2015 at 12:24 UTC

Nikon words: "While not recommended for general photography, the D810A is ..."

At a time when DSLR sales are falling rapidly, perhaps Nikon should focus on cameras for general photography, and not on special solutions for a small niche market.

Direct link | Posted on Feb 10, 2015 at 11:29 UTC as 68th comment | 8 replies
Total: 250, showing: 1 – 20
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