digital camera – Page 8 – Addicted2light

How many megapixels do you need?

Posted on 10 November 201311 November 2013 by Gianluca Bevacqua

I made this simple table for personal use, than I thought it may came in handy to others too, so here we are.

It sums up how many megapixels do you need to print on each of the more common paper sizes available.

Given that the level of quality requested varies according to the kind of image – a portrait will be more enlargeable without artifacts or softness than a detailed landscape, for example – I’ve set three thresholds at 200, 260 and 300 dpi.

Please note that here we are talking about PRINT resolution, not PRINTER one.

If you don’t have this point clear please read one of the basic introductions available online. Let’s suffice to say that normally you will have to “stretch” the megapixel of your picture onto the area you intend to print; to have a quality result you don’t want to stretch them too much, and that’s what I’m talking about.

Printer resolution, on the other end, refers to the way printers manage to actually create an image putting thousand of ink dots one after the other on a piece of paper.

While print resolution – how many megapixels you need to cover the area of a piece of paper – it is alway the same regardless of the device used to create the image on paper, printer resolution varies wildly between models, makers and technologies used.

Panorama multishot Olympus shift 35mm f/2,8 OM Zuiko

And now let’s look at the table. In the first column you find the paper format; in the seconds its size; in the third, fourth and fifth how many megapixels do you need for each print resolution, from the worst (200 dpi, in red) to the best (300 dpi, in green). You may pull it off with 200 dpi if the viewing distance for your print is not very close, especially if there is an actual physical impediment for the people to getting closer; otherwise everyone usually tends to stuck its nose to the print searching for more detail – and at 200 dpi this detail it will simply not be there.

In the last column I’ve listed how many shots you will need to use if you decide to join multiple frames in a matrix fashion to achieve a resolution of 300dpi with a 21-24 Megapixels camera* (first number is the total of shots needed, then how many shots rows x columns).

*With a 20% margin of juxtaposition to join the frames flawlessly

Paper format	Paper size (mm / in)	200dpi	*260dpi*	*300dpi*	*N° of shots* *[rows x columns]*
A0	1189 x 841mm 46.8 x 33.1″	62	89	140	15 [ 5 x 3 ]
	800 x 800mm 31.4 x 31.4″	39	57	89	9 [ 3 x 3 ]
A1	841 x 594mm 33.1 x 23.4″	31	45	70	6 [ 3 x 2 ]
	700 x 700mm 27.5 x 27.5″	30	44	68	6 [ 3 x 2 ]
	600 x 600mm 23.6 x 23.6″	22	32	50	4 [ 2 x 2 ]
A2	594 x 420mm 23.4 x 16.5″		22	35	2 [ 2 x 1 ]
	500 x 500mm 19.6 x 19.6″		22	35	2 [ 2 x 1 ]
A3	420 x 297mm 16.5 x 11.7″		11	17	1

Review: Sony Nex-3

Posted on 10 May 201229 July 2014 by Gianluca Bevacqua

I bought the Sony Nex-3 as a companion to the Fujifilm X100, to be able to use wider and longer lenses while keeping the bag at a reasonable size & weight to travel without too much hassles.

Paired with the Sony 16mm f/2,8 pancake (24mm equivalent) and a 50mm f/1,7 Minolta MD (via an adapter) the Nex-3 is capable to cover, along the Fuji, almost all my photographic needs when I’m not specifically on a photo trip, and without dislocating my shoulder.

Yes, the Canon 5d Mark II and his Nikon equivalents are still the best choice quality wise, but sometimes they became too heavy. And the best camera is never the one that you left in your hotel room…

For this use, as a travel companion alongside the Fuji, the Sony Nex-3 is a mixed bag though.

Resolution wise is pretty good, I’ll say at least on par with the best 12 Megapixels sensors out there.

Raising the Iso uncovers quite a bit of noise, but it is well usable till 1600 Iso (with a bit of post production). I mean: it’s good, just not Fuji X100 good.

The unappealing thing about the Sony is the control interface. Quite frankly I hate the guts of his logic, mostly because it doesn’t have one.

Even after you personalize the back buttons, assigning Iso, Shooting Mode and whatever, control the camera more often than not requires to dig in the menu.

Even more disappointing, the behaviour of the camera changes in its own way; often you push a button and, instead of the function you wish to activate, a message pops up saying that “this function is disabled in this mode”. Which mode? Why? What I have to do to restore it? It’s all a mistery, so you find yourself messing around and pushing things till you enable the function again. And by the way, I use computers since the ’90, and I’m a programmer myself, so it’s not my problem but just poor engineering.

The other thing that make me nut is the focus magnification. It work like a charm with an adapted (manual focus) lens. It work like s…. with Sony lenses. Let me explain. With Sony lenses turning the ring along the lens enable the focus magnification (and this is wonderful, kudos Sony); but you may enable this focus magnification, if you are working in AF, only after the camera locks focus. So it’s pointless!

Speaking of crappy software, the process for updating the firmware is crap.

Let me explain: with every other digital camera that I know of you have to just copy on the card the firmware update file, than complete the process on camera.

Not with the Sony. You have to install on the computer the Sony software, than with the camera tethered follow the on screen instructions. I don’t like installing pointless software. I don’t like installing software that DO NOT RUN on 64 bit Macs and on Lion, forcing me to reboot in 32 bit just to update the firmware (to do so press the 3 and 2 keys at boot).

Frankly, on this I’m speechless.

On the bright side the focus peaking that turns red, white or yellow (your choice) the areas in focus works perfectly, and it is almost more precise that looking at the magnified image on the monitor.

And the tiltable monitor it’s a fair substitute for a finder, given that, thanks to the focus peaking, it let you shoot from the waist much like with Hasselblad or Rollei.

Last thing: if you plan to use the Sony Nex-3 with extreme wide-angles like the wonderful Voigtlander Heliar 15mm you will be better served by its bigger sister, the Nex-5n; this because the Nex-3 sensor has troubles of color shift and soft corners with adapted (not Sony) wide angle lenses.

To all the others I strongly suggest the Nex-3 over the Nex-5n because, even if the last is undubitably better, the price gap is significant: you may find a Nex-3 for as little as 320€ in kit with the 16mm pancake, while the Nex-5n costs more around 650€.

In conclusion: it’s a good camera if you can live using it in almost full auto and / or with adapted manual focus lenses. I’d not buy it as a primary camera, but in tandem with a better one like the Fuji is strongly suggested.

On a “bang for the bucks” scale from 1 to 10 I’d say it’s a 7 1/2, maybe a full 8 if you can live with the crappy controls & software.

Rating: User controls

Rating: Image quality

Review: Fuji Finepix X100

Posted on 29 April 201229 July 2014 by Gianluca Bevacqua

For the guys in hurry I’ll give you a sum up of this review: “holy crap!”.

Ok, maybe some extra details are needed 🙂

Like many others I also was in search of the Holy Grail, something that I may carry everywhere and on journeys and that can still gives me great quality; like a film rangefinder camera, you know! For this job I used both the Leica M6 and the Contax G1. They are amazing, but film price go higher every day, and developing and scanning prices follow. More the good labs, unless you live in a big city, are becoming rare. So this “everywhere” camera now has to be digital. And here was the problem. Till now.

A disclaimer, so that you will can judge if your needs are the same of mine, and so if this review can be useful to you.

I enjoyed a lot both the Leica M6 and the Contax G1, but each one of them had flaws:

– the Contax had no focus confirmation in the finder, and speaking of the finder it was, quite frankly, a crappy one; more the camera was noisy as hell and it has no digital offspring whatsoever;

– the Leica was amazing with even more amazing optics and a spectacular finder; but I found the camera pretty slow to focus to follow action, so I ended up using it almost only in hyperfocal (with excellent results, to be told); more, the Leica digital offspring costs between 2.000 and 7.000 (yes, seven-thousand) euro WITHOUT lens, based on the model you choose (M8 or the full format / empty wallet M9).

And now for the quality level I was aiming at. I normally use a Canon 5D Mark II, often stitching multiple frames, and I’m quite spoiled by its quality; and from an usability point of view the best cameras that I ever owned were a Nikon F4s, a Leica M6 and a Fuji GS645, all three of them almost an “extension” of my own eyes.

So? Here the Fuji X100 came to the rescue.

When I searched online the reviews and the forums for informations about the X100 what I read almost turned me off (you can learn about the technical stuff on Dpreview or Imaging Resource, among others sites). They say, in no particular order, that the Fuji X100:

– it’s clumsy

– AF is slow as molasses

– with the last firmware can’t focus properly

– the lens is prone to flare and not so good at full aperture

– it eats kids 😉

Guess what? I’m really stubborn so I decided to buy one! And I discovered pretty soon that it’s an amazing camera. Yes, the AF is a bit slow, but only in macro (we’re talking under 30cm) with poor light. Unless you spend your time taking pictures of your food I don’t envision this as the primary work of a reportage / travel camera. At normal distances is snappy and precise, even in pitch dark. The lens, especially if you shoot in raw turning on the lens correction in Photoshop, Lightroom or the freeware RawTherapee, is exceptional even at f/2, perfect at f/4 and has an amazing bokeh. I still have to see any flare at all, even shooting in full back lighting and without the hood. Yes, it’s not a Leica. But it’s pretty darn close, and costs like an used Summicron, but comes with a camera attached!

100% crop from the center at f/2, with only a touch of capture sharpening:

More, the sensor is really great, way better than the Sony Nex3 (my previous attempt for a travel camera, that now I use only when I absolutely need to go wide / longer with a couple of adapted lenses). What makes so special the files of the X100, and for what I’ve seen is some sort of Fuji fingerprint, is the gentle roll-off of the highlights (that is also adjustable, like the one of the shadows) that renders the pictures like they were shooted on film. Ice on the cake, the shutter noise, once you disable the fake sounds (!) that are enabled by default, it is almost non existent. An awful lot quieter that a Leica M and still quieter than an Olympus XA. Seriously, I can barely hear the noise in a quiet room with the Fuji glued on my face, even shooting a burst of 3 or 5 pictures for second. And the shutter lag, if the camera is prefocused, is almost non existent too.

Last, but not least, the famous finder. It’s justified all the fuss about the hybrid finder? Yes! The optical one it’s simply stunning, I mean Leica M stunning, and that’s an awful lot. The EVF is pretty good too; nothing to write home about, but I noted that, unlike with the Sony Nex-3 LCD in low light, I’m able to actually use the Fuji EVF to judge focus accuracy.

For my point of view the X100 has only a couple of serious flaws, and with serious I don’t mean deal breakers, just mildly annoying:

1) the notoriously poor designed “OK” button; yes, it is a real pain in the **s, but once you are in the menu you can use an half pressure on the shutter button for the same things; and thanks to the lot of external traditional controls of the Fuji you rarely have to go in the menu at all (pretty much only to enable the self timer, that for an inscrutable reason is not on the “drive” menu).

2) the “focus by wire” ring. With the last firmware update (1.20) it has became usable, but I hate the guts of this thing. Plese Fuji, listen to me: you made the X100 so good that I will buy a X200 only, ONLY, if you put on the lens a proper focus helicoid, so we can “feel” the position of the focus ring and graduate the focusing speed. Oh, I almost forgot: on the next version I want also a Summicron! 😀

Summing up: the Fuji X100 is the first camera that I really like in a long long time. It doesn’t come in your way. After you choose the settings that suits your stile in the menu the camera become transparent, and you can use it simply “by touch” for years to come.

Rating:

Post scriptum for the courious ones: the green thingy on the shutter button it is an home made soft release.