photonius

photonius

Lives in United States United States
Joined on Jan 5, 2008

Comments

Total: 75, showing: 1 – 20
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My pinhole from 1495 still works ;-) Just kidding.

Direct link | Posted on Feb 8, 2016 at 12:12 UTC as 16th comment

The test looks very much like the Hoya HD tests.... Any comparison between these two?

Direct link | Posted on Jan 26, 2016 at 08:31 UTC as 27th comment
In reply to:

deep7: "..with an equivalent maximum aperture of F8 and F12.6 on the 200mm and 800mm equivalent ends". One of the true advantages of m4/3 over larger formats - particularly at very long focal lengths, the extra depth of field is very welcome!

Sorry, I hadn't realized you were quoting, and I made too many logical jumps. The point was that this factor 2 focal advantage of m43 over FF in terms of reach doesn't hold up so well with todays sensors, after all, what counts is how many pixels you get over your subject. m43 has not increased its pixel density as much as FF. But given diffraction limits, photosites will have a limited small size. There is a minimal size for photosites irrespective of sensor size. larger sensors just can have higher MPs. Think of it like the Nikon FF bodies that take DX crop lenses, and just crop the image on the sensor. Of course, not everybody has a 50 or 40 MP FF body (yet), but a 500mm lens on a 51MP body does the same job as a 400mm lens on a 20 Mp m43 (and olympus is still stuck at 16mp). So, comparing to a 800mm starts to be misleading.

Direct link | Posted on Jan 6, 2016 at 22:13 UTC
In reply to:

deep7: "..with an equivalent maximum aperture of F8 and F12.6 on the 200mm and 800mm equivalent ends". One of the true advantages of m4/3 over larger formats - particularly at very long focal lengths, the extra depth of field is very welcome!

Actually, you are wrong. At this tele distances, you want to have maximum resolution for birds or whatever, and zoom in to 100%. Thus, you want to have your circle of confusion - for simplicity - defined as the size of your image sensor pixels. For a Panasonic Lumix DMC-GX8 (20MP), we have 3.3um. For a Canon 760D (crop, 24mp), we have 3.7um. And for a Canon 5DS (FF, 51MP), we have 4.1um. On dofmaster - using 400mm, f6.4, at 20 meters, we get a DOF of 9cm for a Coc of 3um, and 12cm for a Coc of 4um. So, the larger sensors have more DOF. And the m4/3 format does not have a 2x "reach" advantage over the a high res FF like the Canon, only about 1.25x. Still, it looks like a very tempting, interesting lens for that weight!

Direct link | Posted on Jan 6, 2016 at 11:48 UTC
In reply to:

Boissez: Those 300mm shots are just... horrendous. What's the point of having 20MP+ cameras if you're going to strap on a coke bottle? Might as well go with a superzoom like the Panasonic FZ1000 instead.

http://1.static.img-dpreview.com/files/p/TS5472x3648~sample_galleries/5539195489/4968385202.jpg?v=3271

The ship looks not to bad. The bad background is due to atmospheric distortions

Direct link | Posted on Sep 15, 2015 at 15:42 UTC
In reply to:

AEY: Is this is true "Maximum aperture F3.5 - F6.4"
What is minimum aperture?

@cainn24,
thanks for the info. I had missed that they added an aperture in the hx50. hx20 and hx5 don't have one.
anyway, sounds promising if the lens was improved.

Direct link | Posted on Apr 14, 2015 at 20:49 UTC
In reply to:

AEY: Is this is true "Maximum aperture F3.5 - F6.4"
What is minimum aperture?

Can't find anything in the specs, but the previous models had no aperture, just a ND filter that dropped in when necessary. Makes actually sense, because at f6.4 one is already diffraction limited with such small pixel size, so one doesn't want to make it worse by stopping down an aperture.

Direct link | Posted on Apr 14, 2015 at 12:30 UTC
In reply to:

photonius: Looks like a worthwhile upgrade to the HX20, because of the viewfinder, and it didn't gain weight! Only nit-picking is the no RAW. However, I presume the images are highly cooked, so that RAWs would have lots of issues, and probably Sony can't be bothered to provide a professional RAW converter for different computer platforms for such a consumer product.

My major issue would be: is the lens properly sealed this time? The HX20 has problems with getting dust on the sensor (yes, it's not a interchangeable lens camera, but it DOES get sensor dust. Had it twice within the warranty period, was fixed under warranty, but afterwards?). Probably because of the long zoom which causes quite some suction, and it seems there are no good seals in place. But this should be dealt with, the dust on a small sensor can be very visible and if that happens during travel, no way to fix it, it hurts all your pictures.

at cainn24. Well, what has been seen is in video mode, there is quite a bit of barrel distortion, which is not in still pictures.
So, I think it's not only noise reduction, but also CA, distortion, and vignetting correction that is applied. Obviously they implemented this all in their camera software. But I guess for a desktop computer, somebody has to actually sit down and write the RAW converter with all these optimisations (as option) as well (basically the lens profiles). I just think they can't be bothered to do this effort for a P&S. For a dSLR it's expected, so they do it. There may also be the issue of slow write to disk of large RAW format files.
I'm also not sure that third parties would bother to write a RAW converter module for such a camera.

Direct link | Posted on Apr 14, 2015 at 12:16 UTC

Looks like a worthwhile upgrade to the HX20, because of the viewfinder, and it didn't gain weight! Only nit-picking is the no RAW. However, I presume the images are highly cooked, so that RAWs would have lots of issues, and probably Sony can't be bothered to provide a professional RAW converter for different computer platforms for such a consumer product.

My major issue would be: is the lens properly sealed this time? The HX20 has problems with getting dust on the sensor (yes, it's not a interchangeable lens camera, but it DOES get sensor dust. Had it twice within the warranty period, was fixed under warranty, but afterwards?). Probably because of the long zoom which causes quite some suction, and it seems there are no good seals in place. But this should be dealt with, the dust on a small sensor can be very visible and if that happens during travel, no way to fix it, it hurts all your pictures.

Direct link | Posted on Apr 14, 2015 at 10:27 UTC as 42nd comment | 3 replies
In reply to:

tom1234567: I don't no why camera makers keep producing cameras with these
SMALL CRAPPY SENSORS

It's time the public were educated to what they are buying
Instead of being ripped off by ALL camera manufactures

In case you have not noticed, Sony also makes cameras with larger sensors, i.e. the RS models.
However, there is no avoiding the laws of physics for optics. Big sensors, big optics....
If you want a small camera with a good zoom range, this is the only way to go.
To be honest, my wife has a precursor, it's really nice. I often find myself grabbing it instead of my dSLR because it's so convenient. And the built in GPS works quite ok, why can't they get that into dSLRs if they can get it into such a little body.
So, in the end of the day, it's your choice what you want, no need to bash a product if you don't understand the reasoning behind it.

Direct link | Posted on Apr 14, 2015 at 10:18 UTC
In reply to:

mediasorcerer: 24 to 3 or 400 max at the long end would have been fine?
What were they thinking?
A telescope with a sensor on it lol.
Maybe the ufo/aliens crowd are the target market?

the optics is already old, used in previous model.
Actually, works quite well. Compensates to some degree for the fact that there is no RAW, and the jpegs are smeared, so you can't crop as well as one might expect from an 18Mp sensor.

Direct link | Posted on Apr 14, 2015 at 10:14 UTC
In reply to:

Eleson: If optical steady shot means 'in-lens' then I don't understand 5-axis stabilization?

at timur born.
I think it's a combination of sensor and optical stabilisation. that's why you get five axis.

Direct link | Posted on Apr 14, 2015 at 10:12 UTC
In reply to:

TFD: Just wondering if they image the whole sensor. Sony's other18M cameras have a 19M total sensor this email one has a 21M sensor. This makes wonder if they reduced the image area slightly to allow them to shrink the lens. Smaller image area smaller lens.

Interesting point, I noticed this as well. However, it may also be used for shake correction, i.e. in one of the night modes, where multiple images are taken, they have then same extra space at the edges to line up images. Also, their specs list electronic stabilisation in video, so they must have an buffer edge to capture shifted images. Surely, in the past they cropped, that's why the focal length in video was always smaller than for still picture. maybe with a more buffer edge , you get wider video now

Direct link | Posted on Apr 14, 2015 at 10:10 UTC

how boring, the airplane flying by is missing, and the highest parachute jump should be floating by as well. Well, next time .... ;-)

At least the bicycle should have jumped across the sickle

Direct link | Posted on Mar 20, 2015 at 22:39 UTC as 26th comment
In reply to:

photonius: i just found the Kodak Wratten Carbon Neutral Density gel filters. Looking at their transmission curves that you find at Kodak, they seem indeed very color neutral, they also cut the IR, so indeed the magenta cast may be of the past.

Yes, as I mentioned in another reply earlier, most filters, also B+W, singh ray, and others don't filter in the IR, thus leading to color casts with high ND filters. Thus it is nice to see that this issues is finally being noticed. In film days not an issue but it seems it took manufacturers a while to address it with the filters.

Direct link | Posted on Feb 28, 2015 at 19:32 UTC

i just found the Kodak Wratten Carbon Neutral Density gel filters. Looking at their transmission curves that you find at Kodak, they seem indeed very color neutral, they also cut the IR, so indeed the magenta cast may be of the past.

Direct link | Posted on Feb 28, 2015 at 10:36 UTC as 3rd comment | 3 replies
In reply to:

jtan163: What would an IR cut filter be used for?
I was under the impresion most digital sensors had one on board (with some exceptions, Leica M8?).
Would these be used to allow the specialist astro cameras (e.g. D810a and the Canon whtaever it is a) to be used in more normal photography?

most of the strong ND filters give a color cast, because - despite the IR filter in the camera - IR will leak through and cause these color casts. The ND filters have normally no filtering capacity in the IR range, although they reduce the transmission in the visible light. Because the visible light is reduced, the IR that gets through has a stronger effect than normally. The simple way to prevent this is to extend the wavelengths that are filtered into the IR.

Direct link | Posted on Feb 27, 2015 at 11:05 UTC
On article Opinion: Canon EOS 750D and 760D (321 comments in total)
In reply to:

Mike Jacoubowsky: My prediction- The T6s lives a long and happy life and becomes a "Canon to remember." The T6i goes away fairly quickly, replaced by an "SL" version (smaller & lighter, same IQ but enough fewer features to strongly differentiate from the T6s). Give the T6i a year or so.

The one HUGE feature the T6s holds for me? The level. There are some of us (raising both hands on this one!) that have trouble getting shots level, and frequently need to adjust rotation by up to 1.75 degrees or so. Having that level will both decrease time in Photoshop and likely get faster & better shots.

I agree about the level. It should really be in all cameras, as it would also be a good feature for beginners, many P&S cameras have that. I don't have any particular problem holding the camera steady, but looking through the small Rebel viewfinder while taking a UWA shot, it's not so trivial to get it exactly straight. I have to test my camera seriously once, I suspect the viewfinder is not quite straight either.

Direct link | Posted on Feb 17, 2015 at 20:33 UTC
On article Hungarian law bans photos taken without consent (321 comments in total)

It may be a way to suppress opposition and protests. The Hungarian government at present is very right wing and has run already into problems with the EU (of which it is a member) about continuously eroding civil liberties and suppressing opposition. The law may well be mostly applied during demonstrations so authorities can confiscate cameras, mobiles etc. that document abuse.

Direct link | Posted on Mar 18, 2014 at 18:58 UTC as 124th comment | 2 replies

well, the sensor is only 16 bit. "This new sensor is a 19-Mpix, 30.7 x 15.8mm Bayer pattern 16-bit CMOS sensor ... ", so obviously some processing.

Direct link | Posted on Mar 3, 2014 at 22:26 UTC as 22nd comment | 2 replies
Total: 75, showing: 1 – 20
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