Franz Kerschbaum

Lives in Austria Austria
Works as a Astronomer
Joined on Apr 2, 2001

Comments

Total: 82, showing: 1 – 20
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On article CP+ 2017: Hands-on with Sigma's newest lenses (195 comments in total)
In reply to:

sh10453: Hats off to Sigma's engineers. They have been launching some good stuff.
For those complaining of lugging heavy weight gear, just use your phone.

When needing stabilized 2.8 at 135mm we all use our trusty 70-200mm/2.8 lenses. This new lens provide a very different option.

Link | Posted on Feb 24, 2017 at 12:23 UTC
In reply to:

fyngyrz: For astrophotography, which is my particular interest, two of the most troublesome lens problems are chromatic aberration and coma.

Between the two, the additional light capturing capability of a low f-number lens is either lost, or image quality is severely impacted.

If you want to test a lens, take it out on a moonless night, open the aperture all the way, and shoot some stars, making sure the shutter speed is fast enough, and ISO high enough, so that the stars don't streak and so that faint ones are caught as well as bright ones.

The day you find a lens where the stars in the corners are just as round and sharp as those in the center, and the stars don't have red and blue halos... that's the day you've found a good lens.

I own quite a bit of Canon-L glass. I have yet to find one that's actually very good at any of this. By the time you stop them down to where they actually work reasonably well, you've lost all the advantages of the wide aperture.

It's really annoying.

I made this quick Astro comparison to the Canon 1.2 https://www.dpreview.com/forums/post/58887010

Link | Posted on Feb 15, 2017 at 11:26 UTC
In reply to:

davids8560: I had the 995 and I still have the 4500. Great cameras! But was baffled when they rolled out the S4 and S10VR!

Same with me!

Link | Posted on Feb 2, 2017 at 21:26 UTC
On article Canon EOS M5 added to studio scene comparison tool (87 comments in total)
In reply to:

QuikFrame: I'm a complete novice, but I struggle to understand how to make good use of this information when the lenses themselves differ here.

Moreover I dont understand why they are not using the raw developer that the company provides. It is part of the package typically . DPP by canon especially for new cameras is typically miles ahead of LR ...

Link | Posted on Dec 9, 2016 at 07:55 UTC

Nothing about battery life?

Link | Posted on Oct 14, 2016 at 08:10 UTC as 15th comment
On article Updated: Canon EOS 5D Mark IV real-world sample gallery (485 comments in total)

I never understood why they do not use canon dpp for raw development - the original system that comes with the cam as a package but a beta version of a third party...

Link | Posted on Sep 5, 2016 at 19:18 UTC as 30th comment | 6 replies

Another abandoned design that I really miss is the swivel body of the nikon coolpix 990 to 4500 cameras. They where my entry to the digital world and I still miss the great functionality at times....

Link | Posted on Aug 19, 2016 at 23:41 UTC as 29th comment
In reply to:

Franz Kerschbaum: For those on fb - I have also produced a short video from my pics! https://www.facebook.com/franz.kerschbaum.9/videos/1102941153061985/?l=1494659078903947445

Better link maybe: https://www.facebook.com/franz.kerschbaum.9/videos/1102941153061985/?hc_location=ufi

Link | Posted on Jun 24, 2016 at 11:59 UTC
In reply to:

iTrax: very cool.....
would use of Astrotracer ( like in Pentax K-1 ) make this project easier / better?

No since Astrotracer is using the GPS and cam orientation to counterrotate the earth rotation and that is not what is neede here ...

Link | Posted on Jun 24, 2016 at 08:12 UTC

For those on fb - I have also produced a short video from my pics! https://www.facebook.com/franz.kerschbaum.9/videos/1102941153061985/?l=1494659078903947445

Link | Posted on Jun 24, 2016 at 08:11 UTC as 11th comment | 1 reply

I did the same very recently during a fantastic Aurora display! http://www.dpreview.com/galleries/0055445271/photos/3470133/aurora-over-the-atlantic

Link | Posted on Jun 24, 2016 at 08:09 UTC as 12th comment
On article DxO OpticsPro 11 brings advanced Raw noise reduction (109 comments in total)
In reply to:

wjansen: I have version 10 and wonder must I pay to upgrade to 11?

I have a commercial licence so this is before tax! I purchased it via my dxo account and that was the offer ...

Link | Posted on Jun 5, 2016 at 09:09 UTC
On article DxO OpticsPro 11 brings advanced Raw noise reduction (109 comments in total)
In reply to:

joe6pack: Can I install DXO 11 along with older version without interfering with earlier installation?

Yes you can. Checked it yestreday. But there is not reason to do so. All other settings and attachments are taken over ...

Link | Posted on Jun 3, 2016 at 08:12 UTC
On article DxO OpticsPro 11 brings advanced Raw noise reduction (109 comments in total)
In reply to:

wjansen: I have version 10 and wonder must I pay to upgrade to 11?

I paid 57 euros yesterday ....

Link | Posted on Jun 3, 2016 at 08:11 UTC
On article DxO OpticsPro 11 brings advanced Raw noise reduction (109 comments in total)

Just downloaded the DXO 11upgrade to my DXO 10 elite installation for 57 euro. Could not be happier after testing it on my two notebooks (a dell mobile workstation and a MS surface 4 pro). The new prime NR is really faster (which is very good since the old one was quite slow on my surface) and in high ISO cases better. The new quick look full screen sorting is also quite nice and more time efficient. The new face recognition features sound interesting but had not chance to test this.

Link | Posted on Jun 3, 2016 at 08:10 UTC as 8th comment

Thats a fantastic add. In the meantime I do most of my macro work with the m3 (having also a 7d2 and a 5d3!) because of its convenient screen and handling with the 135/2.8 IS macro. I was really missing a short focal length alternative in some cases. Not have to use my mt-14ex2 flash is also nice ...

Link | Posted on May 11, 2016 at 17:19 UTC as 24th comment
In reply to:

Leonp: Insects have eyes like this camera. How would they compute their data?

The ESA Integral IBIS camera even has a very similar mask! Scroll down! http://www.isdc.unige.ch/integral/outreach/integral

Link | Posted on Feb 17, 2016 at 16:17 UTC
In reply to:

Leonp: Insects have eyes like this camera. How would they compute their data?

Nothing to do with insect eye . It works like the coded mask systems that we use for years in gamma ray astrophysics. But there it is much easier since we register individual photon events and head for relatively small spatial resolutions and very low "pixel" counts". Here a nice illustration how the principle works: http://sci.esa.int/science-e-media/img/d0/Figure_11_SPI_coded_mask.jpg

Link | Posted on Feb 17, 2016 at 16:14 UTC

We used coded mask systems for years in gamma ray astrophysics. But there it is much easier since we register individual photon events and head for relatively small spatial resolutions and very low "pixel" counts". Here a nice illustration how the principle works: http://sci.esa.int/science-e-media/img/d0/Figure_11_SPI_coded_mask.jpg

Link | Posted on Feb 17, 2016 at 08:43 UTC as 17th comment | 1 reply
On article Heavy hitter: Sony FE 24-70mm F2.8 GM first shots (349 comments in total)
In reply to:

Franz Kerschbaum: Why can RAW be not RAW? Its really bad for some application like Astronomy when such corrections (e.g. vignetting) are already applied. We have our own, controled measures to do it. This tendency is really fustrating

We use IRAF, MIDAS, and typically Phyton based pipelines directly developed for our ground (e.g. ESO VLT) or space based instrumentation (e.g. ESA Herschel). For Acquisition and some quick look analysis on our smaller student project telescopes (60, 80 and 150cm) we have MaximDL with the different SBIG cameras. (concerning flats for camera lenses, I just recently saw that more and more amateurs use these flatfield boxes they have for the telescopes - not so expensive and complex. Sensor dust flat fielding is a must for most of them outside the ideal world!)

Link | Posted on Feb 8, 2016 at 11:12 UTC
Total: 82, showing: 1 – 20
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