dopravopat

dopravopat

Lives in Slovak Republic Bratislava / Wien, Slovak Republic
Works as a IT technician
Joined on Feb 28, 2007
About me:

I live both in Bratislava in Slovakia and Vienna in Austria, these two cities share one common space for me.

Comments

Total: 144, showing: 1 – 20
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On photo McMurdo magic in June in the My Best Photo of the Week challenge (12 comments in total)

Really advanced PP in this shot! This is not a photogprah anymore, this is ART! Well done!

Link | Posted on Jun 22, 2016 at 12:50 UTC as 1st comment | 1 reply

People who buy this lens probably have silver wires from their amp to their similarly overpriced hi-fi speakers. To play mp3s on them. And they buy this lens to shoot jpegs out of the camera anyway. No doubt there is a market for such products.

Link | Posted on Jun 20, 2016 at 19:07 UTC as 65th comment | 1 reply
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

@John C Tharp:
OK, maybe it is not the microlenses, but something on the sensor, or before it, has the effect that only all light coming from an f1.8 or slower lens, or stopped down to more than f1.8, is captured. Having a faster lens would not give a brighter image on a DSLR, if the ISO value were really the same. Of course the cameras keep reporting whatever ISO you set them to, but they rise it without your knowledge to compensate for the fact that the sensor cannot handle the extra light from superfast lenses faster than f1.8. Even RAW files are affected by this and the only way to see a difference is because the camera is rising the sensitivity. But if oyu manipulate the camera into thinking no lens is attached and take shots af f1.4 and f1.8, you get images where you see that there is no real brightness difference between f1.4 and f1.8, only shallower DOF af f1.4.

Link | Posted on Jun 14, 2016 at 11:46 UTC
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

@Dr_Jon:
I can do the experiment once again, under controlled conditions. As far as I remember, also the pixels in the center of the frame were not as bright at f1.4 as one would expect. The pixels near the corners must have been worse off, but this is not normal lens vignetting. Also, the EOS 60D with the Sigma 50 mm f1.4 does not have any peripheral illumination correction and I shoot RAW anyway. I already sold my Sigma 85 mm f1.4 so I cannot do the experiment with it, but I expect it would give similar results.

Link | Posted on Jun 14, 2016 at 11:36 UTC
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

@ProfHankD:
Of course they are not a problem of the lensmaker. But this begs the question why anybody should get a faster lens than f1.8 for extreme low-light applications, as the benefit of having f1.4, f1.2 or even f1.0 does not manifest itself in lower noise levels, but only in shallower depth of field. To speak for myself, I did not shoot with the Sigma 50 mm and 85 mm f1.4s any wider than f1.8, as it provided no lower noise benefit and the DOF was already thin enough. Maybe my claim that the microlenses on the sensor have f1.8 is wrong, but there clearly is something in the camera which is causing the effect described and my suspect is something in the microlens array, or maybe low pass filter.

Link | Posted on Jun 14, 2016 at 11:36 UTC
In reply to:

dopravopat: Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

I can confirm this by experiment with my Sigma 50 mm f1.4 on the Canon EOS 60D. The experiment is really simple and requires to take a picture at f1.4, then release the locking of the lens mount and rotate it a bit, so the contacts are disconnected. The camera does not know that a lens is attached and does not know it to be f1.4, so it does not automatically rise the sensitivity, while still displaying ISO 100. A picture taken now shows a clear difference in brightness of the image, even though the illumination conditions and exposure time remained the same. You can connect the lens again, stop down the lens to f1.6, take a picture. Then press the preview DOF button and while holding it disconnect the lens electrically by rotating a bit, so the aperture remains locked in the f1.6 position but the camera does not get this information, and you get the same effect, but with a smaller magnitude. From f1.8 above there is no difference. So the camera sensor is limited by its own microlenses.

Link | Posted on Jun 14, 2016 at 06:48 UTC

Has something changed, or do sensors still have f1.8 microlenses? If they still have them, then the only benefit of a faster than f1.8 lens is shallower DOF, but not lower noise.

Link | Posted on Jun 14, 2016 at 06:14 UTC as 18th comment | 11 replies
On article Fast telezoom: Sigma 50-100mm F1.8 sample images (164 comments in total)
In reply to:

dopravopat: I have shot about 500 images with this lens and must say that it is worth every cent I paid for it. Those who say I should buy a Canon 85 mm f1.8 either do not know what they are talking about or are comparing apples and oranges.

The only negative thing to write about the Sigma 50-100 f1.8 is the tripod collar, which cannot be removed and always gets in the way when operating the lens. I really wonder why Sigma decided to design the tripod collar like that, anyway I rotate it, it always bothers me and I would rather have no collar at all than a fixed one like this.

Just look in my gallery, the newest image. I cannot post images in the comments here and the link ran out of time, as I feared.

Link | Posted on Jun 13, 2016 at 18:39 UTC
On article Fast telezoom: Sigma 50-100mm F1.8 sample images (164 comments in total)
In reply to:

dopravopat: I have shot about 500 images with this lens and must say that it is worth every cent I paid for it. Those who say I should buy a Canon 85 mm f1.8 either do not know what they are talking about or are comparing apples and oranges.

The only negative thing to write about the Sigma 50-100 f1.8 is the tripod collar, which cannot be removed and always gets in the way when operating the lens. I really wonder why Sigma decided to design the tripod collar like that, anyway I rotate it, it always bothers me and I would rather have no collar at all than a fixed one like this.

The flare resistance of the 50-100 f1.8 is pretty good, much better than the 18-35 f1.8 which handles flare horribly.

Here is an image taken with 50-100 f1.8 at 100 mm f1.8:
https://s3.amazonaws.com/masters.galleries.dpreview.com/3463901.jpg?AWSAccessKeyId=AKIAIWXD4UV3FXMIDQLQ&Expires=1465839543&Signature=AIHW8P%2FSANeCDM9qP4pmzIhqLIg%3D
Sligtly rotated and cropped. The setting sun is directly in the image, not hidden behind anything.

Link | Posted on Jun 13, 2016 at 16:40 UTC
On article Fast telezoom: Sigma 50-100mm F1.8 sample images (164 comments in total)
In reply to:

dopravopat: I have shot about 500 images with this lens and must say that it is worth every cent I paid for it. Those who say I should buy a Canon 85 mm f1.8 either do not know what they are talking about or are comparing apples and oranges.

The only negative thing to write about the Sigma 50-100 f1.8 is the tripod collar, which cannot be removed and always gets in the way when operating the lens. I really wonder why Sigma decided to design the tripod collar like that, anyway I rotate it, it always bothers me and I would rather have no collar at all than a fixed one like this.

If you prefer to swap lenses constantly and can live without all the other focal lengths then feel free to do it your way, carrying around three lenses, losing time when swapping them, and exposing the DSLR mirror box to potential dust. Also, when shooting with two or more primes, each one rendered the colors a bit different, which needed special care in PP to get consistent look. With one lens, you do not need to handle each focal length differently. Since I do not plan to go FF I really do not need FF coverage.

Link | Posted on Jun 13, 2016 at 09:24 UTC
On article Fast telezoom: Sigma 50-100mm F1.8 sample images (164 comments in total)

I have shot about 500 images with this lens and must say that it is worth every cent I paid for it. Those who say I should buy a Canon 85 mm f1.8 either do not know what they are talking about or are comparing apples and oranges.

The only negative thing to write about the Sigma 50-100 f1.8 is the tripod collar, which cannot be removed and always gets in the way when operating the lens. I really wonder why Sigma decided to design the tripod collar like that, anyway I rotate it, it always bothers me and I would rather have no collar at all than a fixed one like this.

Link | Posted on Jun 13, 2016 at 06:31 UTC as 2nd comment | 5 replies
On photo Turntable at Durango, Colorado in the Retro: Turn table challenge (2 comments in total)

Trolling is a art.

Link | Posted on Apr 23, 2016 at 07:41 UTC as 1st comment
On article Leica Q In-depth Review (1118 comments in total)

I came here just for the comments.

Link | Posted on Mar 24, 2016 at 12:51 UTC as 95th comment

I suggest you display four settings in the image comparison tool, ISO 100, 1/160 s, +5 EV

upper left: Canon EOS 80D, upper right: Nikon D7200
lower left: Canon EOS 70D, lower right: Nikon D7100

The images speak for themselves.

Link | Posted on Mar 23, 2016 at 08:23 UTC as 35th comment | 11 replies

Nice. I have it already pre-ordered. I hope the AF on a EOS 60D will be better than with the the 18-35.

Link | Posted on Mar 10, 2016 at 06:52 UTC as 42nd comment
In reply to:

ttran88: If Canon bought Sigma, none of these would have been released. Stay true Sigma.

They might have been released as premium Canon L glasses with a price higher at least 50% over the current Sigma prices.

Link | Posted on Feb 23, 2016 at 10:09 UTC
In reply to:

dopravopat: I can't wait for the first sample images taken with the 50-100 f1.8 as well as a review.

I wonder what will be next. 125 - 250 mm f 2.2 for APS-C with a 2x tele making it a 250 - 500 mm f4.5? Even at f2.2, the 125 - 250 would be pretty huge. But there is no real long tele zoom longer than 150 mm and brighter than f2.8 for APS-C so far. All the long zooms are FF.

Yes, 4 kg seems like a reasonable guess, however the price could be around 3.5K, being Sigma, not Canon. But I am certain that a market for such a lens is virtually non-existent.

Link | Posted on Feb 23, 2016 at 08:01 UTC

I can't wait for the first sample images taken with the 50-100 f1.8 as well as a review.

I wonder what will be next. 125 - 250 mm f 2.2 for APS-C with a 2x tele making it a 250 - 500 mm f4.5? Even at f2.2, the 125 - 250 would be pretty huge. But there is no real long tele zoom longer than 150 mm and brighter than f2.8 for APS-C so far. All the long zooms are FF.

Link | Posted on Feb 23, 2016 at 07:12 UTC as 59th comment | 2 replies

Shut up and take my money!

I hope this rumor is true.

Link | Posted on Feb 20, 2016 at 20:10 UTC as 18th comment
On article Otherworldly? Lomography introduces Jupiter 3+ lens (163 comments in total)

Whoever wrote this marketing blurb was either an idiot or very smart. Either way, the customers who buy this are much easier to fit in the idiot/very smart dichotomy.

Link | Posted on Jan 22, 2016 at 08:41 UTC as 23rd comment | 1 reply
Total: 144, showing: 1 – 20
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