Petka

Petka

Joined on Jan 8, 2012

Comments

Total: 425, showing: 1 – 20
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Looks like I have to invest even more to Art…

I just hope they do not keep putting these new lenses out too fast.

Direct link | Posted on Feb 12, 2015 at 09:48 UTC as 51st comment | 1 reply
In reply to:

Demerzel: Interesting camera. I would like to see comparison images of the same scenes from this camera and the 810. Images such as portraits, landscape, low light shots, etc. Enabling me to see the effect of the new filter on regular shooting. This may be an all-round camera and we don't know it.

Interesting! Bit off topic, but I have a pair of mountaineering prescription sunglasses, which were darkened by the optician. They actually came out a bit too dark, and they exhibit this strange phenomenon of dark objects turning brownish-purple. Is this caused by them blocking other colors almost too well making near IR or this H-alpha frequency stand out? Thanks.

Direct link | Posted on Feb 11, 2015 at 07:55 UTC
On Canon EOS 5DS / SR First Impressions Review preview (2270 comments in total)
In reply to:

TGBN: EOS 5DS = Good news for people from Zeiss :-)

Sigma even more...

Direct link | Posted on Feb 10, 2015 at 08:11 UTC
On Go wide! Hands-on with Canon's 11-24mm F4 L article (224 comments in total)
In reply to:

fmian: I'd be interested to know what kind of distortion this thing has.
Considering the 15mm is called a fisheye and this 11mm is called rectilinear.

All rectiliner lenses distor in the corners, but with normal lenses and longer we do not notice it as it is so slight. With wide angles this problem becomes noticeable, but unfortunately it is not caused by bad design, but the nature of the rectilinear projection itself. So nothing can be done about it optically, or in post (without loosing the rectilinearity itself in the process = getting a fisheye effect).

Direct link | Posted on Feb 6, 2015 at 10:50 UTC
On Go wide! Hands-on with Canon's 11-24mm F4 L article (224 comments in total)
In reply to:

adhall: ok, I have Nikon gear and have been eyeing the 14-24 for a while. But how good is this?!? Serious Canon envy at the moment...

Nikkor 14-24 is, maybe surprisingly, one of the sharpest, if not The Sharpest, super WA, including primes. Problems are flare (Canon 11-24 looks similar with bulging front element) and bulk/weight. Like I already said, I am switching to 20mm prime, but different people have different needs. Anything wider than 20mm gets a bit difficult to handle for documentary photography, for landscape & architecture, fine.

Direct link | Posted on Feb 6, 2015 at 10:34 UTC
On Go wide! Hands-on with Canon's 11-24mm F4 L article (224 comments in total)

I assume it is an amazing WA.

I have had the Nikkor 14-24 for over 2 years, and do not use it much at all. Now replacing it with 20mm f/1.8 Nikkor. Lighter, more convenient, wide enough.

Make your conclusions...

Direct link | Posted on Feb 6, 2015 at 09:37 UTC as 52nd comment
On 3,200MP LSST camera gets construction approval article (257 comments in total)
In reply to:

star shooter: Ok, all BS aside, why hasn't this camera been designed to work in Space, like the HST?

After all, if one is spending $$$ on this camera, another few mil $$$ could have been spent to launch it into a geo stationary position, 300kms above the planet.

Who's paying, who is manning this beast and by what means?

Geostationary position is 35750 km from the center of the earth (29410 km above surface). Not 6666km.

Direct link | Posted on Feb 3, 2015 at 09:46 UTC
On 3,200MP LSST camera gets construction approval article (257 comments in total)
In reply to:

badi: 7 years to go....

Joke aside... it's a bit sad when you realize the pace these science projects advance... i mean, ok, it is a big project...but 7 years to build... is only one guy building and caring the bricks on the mountain or what...

With Mount Palomar telescope just the molded glass for the mirror took three years to cool down. Then began the grinding and polishing...

Direct link | Posted on Feb 3, 2015 at 09:41 UTC
In reply to:

fmian: From their website:
'APS-C (Both Macro and Normal shooting)Full-frame (Macro shooting only)
i.e. Slight vignetting will appear for Full-frame camera at normal shooting, while no impact for Macro shooing'

I was initially under the impression (after only seeing the first line quoted in another article) that the lens would not focus to infinity on full frame.
With the note explaining the vignetting does this mean that there is a large variation of magnification when focus is changed from close to far?

When a lens is focused at infinity, it has the widest field of view. If focused to 1:1 it will be twice the focal length away from the sensor, and of course also the field of view will be halved (and image circle size doubled). For this reason there will be no vignetting when shooting macros and relatively close. For the same reason exposure has to increased 2 stops (light falls on 4 times the area), but nowadays cameras take care of this automatically, and apparently using modern cameras does not require any basic knowledge about optics anyway anymore.

Large variation of magnification? At infinity the magnification is zero, at the closest this can shoot twice the real size...

Direct link | Posted on Jan 15, 2015 at 13:31 UTC
On Zeiss introduces 'no distortion' Otus 1.4/85mm article (338 comments in total)
In reply to:

Sangster: Only US$4490!

AF would be slow and need strong motor in a lens with heavy brass focus threads and tight tolerances. Also the optical design was done with total disregard to the weight of the moving element groups. So I would say there would be compromises in one or another direction (slow focus or lesser IQ).

Direct link | Posted on Sep 9, 2014 at 08:46 UTC
On Zeiss introduces 'no distortion' Otus 1.4/85mm article (338 comments in total)
In reply to:

Pixel Pooper: People whining about no AF, this lens is not for you. A good MF shooter should be more accurate than any AF system.

Few points: After some calibration I can now nail the focus with Sigma 50mm f/1.4 Art to the eye at closeup distances. 100% accurate.

Longer lenses actually have larger focus movements than shorter focal length lenses, so AF is easier and more accurate with those.

Direct link | Posted on Sep 9, 2014 at 07:55 UTC
On Zeiss introduces 'no distortion' Otus 1.4/85mm article (338 comments in total)
In reply to:

mpgxsvcd: I can't fathom this lens being worth 10 times what a good Nikon 85mm F1.4 is worth. It may be better but it isn't 20 times better.

New f/1.8 85 mm Nikkor is just as good as the faster f/1.4, but cheap.

Direct link | Posted on Sep 9, 2014 at 07:51 UTC
On Zeiss introduces 'no distortion' Otus 1.4/85mm article (338 comments in total)
In reply to:

new boyz: This is what you get when the ultimate goal is to get the highest possible IQ. Other designs compromise IQ with price/AF/etc.

Autofocus might compromise IQ: for fast autofocus now in demand lens needs to have lightweight moving parts, which means either lighter movable lens groups or lighter materials like plastic in lieu of brass, or both. Manual focus lens does not have these design limitations, and the tolerances can be tighter (= stiffer focus movement).

Direct link | Posted on Sep 9, 2014 at 07:49 UTC
In reply to:

simpleshot: There are five Beatles in that picture, if you count the car.

It is a Beetle... so only 4

Sorry to spoil the fun...

Direct link | Posted on Aug 12, 2014 at 06:35 UTC
In reply to:

Sdaniella: Fujinon XF 1.5x.sensor.factor 18-135mm F/3.5-F/5.6 R LM OIS WR

Fujinon XF ff.equiv.fov 27mm-202mm F/5.3-F/8.4 ff.equiv.dof R LM OIS WR

ad=5.1mm wide to 24.1mm tele (aperture diameters)

Relative aperture a.k.a. f-stop is the only relevant measurement. Claiming otherwise shows total ignorance about optics.

Direct link | Posted on Jun 17, 2014 at 10:53 UTC
On Nikon AF-S Nikkor 58mm f/1.4G review preview (415 comments in total)

I have shot portraits with this and Sigma ART 50mm, and while NIkkor is unique in its own way, I still choose the Sigma for out-of-this-world sharpness even full open.

It is also 60% cheaper...

Which shows that it is possible without Zeiss Otus price, with AF.

Direct link | Posted on Jun 3, 2014 at 11:18 UTC as 13th comment
On Sigma 50mm F1.4 DG HSM | Art Lab Test Review preview (569 comments in total)

Just shot my first assignment with Sigma 50mm f1.4 Art on Nikon D4: totally amazingly sharp full open. Accurate and fast AF also. It is a keeper! Next I have to play with D800e...

Direct link | Posted on Jun 2, 2014 at 13:49 UTC as 34th comment
On SherpaFund raises money after Everest avalanche article (21 comments in total)
In reply to:

MikeFairbanks: They endure a lot to prepare for their climbers, so I hope a lot of money is raised for the families.

On a separate note, I don't like what happened to Everest. The climbing routes are covered in discarded oxygen tanks, tattered abandoned tents, human waste that doesn't decompose, and worst of all, over two hundred dead bodies, preserved forever (or until they are removed by avalanche or people).

It's a tragedy that they couldn't go home and it's a tragedy that they are still there. It's also a tragedy for one of the most beautiful pieces of nature in the world. Imagine if Crater Lake had 200 dead floating, preserved, on its surface each day. Not cool.

Most visible trash, oxygen tanks and ripped tents, is at South Col, a windswept pass at 8000m, site of camp IV. Only climbers go there and it is really not a photographic place, trash or no trash. There is no trash problem to make the place less photogenic. What comes to dead bodies they are listed under biodegradable waste in the climbing rules and there is no need to bring them down. Doing it would actually cause more damage than just leaving them there.

There is some old trash in the glacier, it will be ground there for about 500 years before it is spit out at the terminus. Not likely to be much left.

I have visited EBC 4 times since -85, last time in -09.

Direct link | Posted on May 24, 2014 at 17:40 UTC
On SherpaFund raises money after Everest avalanche article (21 comments in total)

While losing the main breadwinner in any family is a disaster to all concerned, Sherpas are the wealthiest ethnic group in Nepal. A high altitude sherpa earns annually 10 to 20 times the national average. True poverty lies in the western Nepal, where no tourists and no relief funds go. Namche, the tourist hub of Khumbu, is per capita the wealthiest city in the whole country.

Something to think about also.

Direct link | Posted on May 23, 2014 at 12:49 UTC as 6th comment | 7 replies
In reply to:

Thorgrem: Very nice to see big professional tele lenses which arent ugly white. Or does this one also comes in white?

Many nature photographers wrap camo tape on these. Why not white gaffer's tape if you are worried about to noonday sun.

Direct link | Posted on May 15, 2014 at 05:32 UTC
Total: 425, showing: 1 – 20
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