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Messages - Aglet

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EOS Bodies / Re: New high resolution camera
« on: November 19, 2013, 01:39:32 AM »
I don't really give DXO the time of day anymore. There are far more useful benchmarks for camera equipment out there that provide more useful insight. DPR, PhotoZone, TDP, etc. are vastly superior resources.

About all I find useful of their lens tests is simply comparing the results of lenses tested on the same body, using the field measurement results so you can see the relative contrast plotted as varying colors.  In this way you can get a feel of how a given lens they tested MIGHT perform, relative to itself or sometimes others, at different apertures and-or focal lengths.

Third Party Manufacturers / Re: Anyone try the Olympus OM-D E-M1?
« on: November 19, 2013, 01:24:27 AM »
I still have my E-510 and lenses. Those lenses are superior to any of the micro four thirds lenses and just need an adaptor to work on a micro four thirds body... The 50-200F2.8-3.5 lens was certainly L glass quality... who knows what will happen in the future... they might see action again :)

I haven't had time to read much yet but so far that seems the consensus; the older 4/3 lenses are better, likely because of longer registration distance reducing distortion and other optical compromises in the MFT geometry. Apparently Oly's (old) zooms are very good performers and some of those older lenses can be had pretty cheap as people moved to other systems.

Rumor somewhere I read today has Olympus putting out an "entry level" body in early 2014 that will be a bit like the E-M5, with some tweaks.  I hope this new body retains the shape and feel of the EM1.

Currently the EM5 is selling for less than $600, a pretty big price cut and tempting too, if I hadn't already experienced the siren-call of the EM5.

Muddying my decision, Fuji XM1 and XA1 are fairly economical APSC size sensors in lightweight bodies with similarly short registration distance and there's a good selection of (cheap) X-mount adapters to allow virtually any other lens to attach and use in manual mode.  MUCH cheaper option than Sony's new FF A7r.
Kitted with the 16-50mm OIS lens, essentially for free, this makes for an economical and versatile still imaging tool also and a viable walk-around street-shooter with the cheap kit lens.

EOS Bodies - For Stills / Re: Any reason to choose a 7D over a 70D?
« on: November 15, 2013, 01:30:35 PM »
Will it matter if you shoot in raw?

from the limited tests I've done, I'd choose the 70D's raw files over the 7D's.
Get the 7D if you NEED the extra speed, buffer, built quality, weather-resistance and control layout
Else the 70D is perfectly capable.

Third Party Manufacturers / Nikon D5300, now shipping
« on: November 14, 2013, 03:37:31 PM »
Once again, evolutionary improvements on an already good Nikon consumer series body leave competitors behind in many metrics.. and price.

One of these is on my xmas list.  2 more if it performs really well.

They seem to have changed the grip to body spacing a little from previous models, I hope it's still comfortable to hold like the 5100/5200. 
WiFi and GPS abilities, + 1080P at 60fps will be features useful to some.

EOS Bodies / Re: New high resolution camera
« on: November 14, 2013, 03:31:51 PM »
How exactly do DxO mark arrive at that headline lens "score"? an average of lens performance across focal lengths/apertures? wide open? stopped down?
As JRista explained, DxOmark appears to have a Nikon bias on lens tests - BUT, that's because, for whatever their reasoning, part of their lens test also included a measurement that takes into account the signal to noise ratio of the camera body it's being tested on.  Possibly for consideration of final noise quality in printing.
The innately lower noise Nikon bodies thus boost Nikon lens scores.

@jrista, unfortunately I can't offer any advice on astro gear, that's out of my league.  I just admire some of the work others have done in this area.
We have dark-sky-preservation areas in my part of the country but I haven't taken advantage of any of them.  We also have about 3000 more feet of thick atmosphere to contend with. I was momentarily motivated to try when, after shooting some handheld dark sky shots my my d800 and 14-24, I could actually see the potential.  I only took a few tripod based shots, very quickly in -20 degree weather, so I could finally see what this sort of shooting could be like.  It's something I'd have to put some thought and effort into to make it worthwhile and I'm thinking I just might do so this winter... If we can ever get any clear skies and tolerable temperatures.

Third Party Manufacturers / Anyone try the Olympus OM-D E-M1?
« on: November 14, 2013, 01:54:25 AM »
I see that it's performance levels are impressive and I've been intrigued by MFT for a while.  I'd have to see what the available lenses are like, some seem to have a lot of native distortion before in-camera correction.

I played with one in the store tonite and WOW!  I LIKE IT!  Feels like it was custom made for my hand, yet nice and compact, unlike my very comfortable but mugh larger crop and FF DSLR bodies.

AF was super fast under indoor lighting.  Not what I've come to expect from mirrorless, much more like newer DSLR and PDAF.

I'm definitely going to have to spend some time playing with one.
At base (200) ISO the files look, pixel-per-pixel, pretty close to the d800 output at 200 ISO.
Hmmmm...  The Fujis are really nice but methinks I small new Oly toy is now higher on my lust-list.

Third Party Manufacturers / Re: Nikon 58/1.4 - $1,700!!!
« on: November 14, 2013, 01:43:48 AM »
I've got a few Pentax lenses that test poorly yet produce nice images so it's not always about ultimate corner-to-corner sharpness and low CA.
Still, however good this new 58mm is, I'll be hard pressed to buy it to get just a little more something from it over my old 50/1.4.  UNLESS I actually need it for night photography where I need the pinpoint lights to look as crisp as they should.

EOS Bodies / Re: New high resolution camera
« on: November 14, 2013, 01:34:28 AM »
You should directly compare the 14-24 corners to canon's 16-35 corners. Sadly (and I own this lens), Canon's corner and edge performance is really atrocious.

Yes, I decided to forego the 16-35 in for the 17-40 instead; was definitely better for landscape type shots from what I saw.

Interesting, that while Nikon and Canon have chosen different paths, the final results are quite similar...

yes, in most cases.

Seems like WA zooms for FF are a weak area, likely difficult to design; I've yet to find a satisfactory WA zoom in the 16-18 to 35-50 mm range.
It looks like the lower end Nikon 18-35mm is winning for performance/cost right now.  Add a 14mm Samyang for that extra wide shot and I can save a bunch of $ as well.

I've got a Tokina 17-35/4 which is very nice from 21-35mm but the 17-20 range on mine is very soft on one side so will be sent in for a warranty tweak.  I also had the Nikon 17-35/2.8.. sharp in center but performance fell off quickly so even on a crop body it had poor corners.
I just got an old Sigma 17-35mm which I've yet to try.
Hopefully Sigma or Tamron will throw their best lens design software at this problem and come up with a better solution soon if the OEM guys don't provide better.

BTW, if you're into astro, I've heard Samyang's 24mm is also good as far as coma is concerned.

Portrait / Re: And yet again...great talent trumps any amount of equipment
« on: November 12, 2013, 11:50:07 PM »
feel free to suggest those to their editor
if they run we'll cut you in for a finder's fee. ;)

Lenses / Re: How many megapixels can these lenses resolve?
« on: November 12, 2013, 11:46:27 PM »
- if some of the lenses are hitting the top end of that sensor - would using a Nikon/Sony 36MP test vehicle let us really see where the lens hits its peak? Until Canon brings out their own high MP body, of course...
Putting a finer resolution sensor behind any given lens will get you a little more total image resolution but gets to be dimishing returns pretty quickly.

Like Pi sez, there are other factors too, mostly what contrast ratio is the bottom end of acceptable for these MTF tests.  You can resolve more if you accept lower contrast.

On Photozone, you can get a bit of a sense of this if you compare the same lens tested on an 8MP 350D vs the 15MP 50D.  If it doesn't max out on the 350d, how high up does it get on the 50d?  It'll likely resolve more LP/PH on the 50d vs 350d but the lense may not be able to max out either of those bodies.
On some lenses the result may be very close or at max on the 350d but will it also be max on the 50d?  If so, heck of a good lens, if not then we're on that diminishing returns part of the curve where the 15MP body may be capable of more.

AA filter strengths and other processing factors also come into play..

So the only thing these kinds of tests, from DxOmark or photozone etc, are good for, is comparing different lenses on the same body if they're evaluated with the same method.  Which, for a given site, is usually consistent enough to be useful for this purpose.
It's a bit of extrapolation to try compare the same lense on different bodies as AA filters and internal camera processing are relatively unknown variables to us.

many grains of salt...

Portrait / Re: And yet again...great talent trumps any amount of equipment
« on: November 12, 2013, 11:28:13 PM »
It always amazes me what kind of images are popular with the masses, even if it's just a fad.
I really gotta get more twisted and come up with some weird cr*p myself.  Shooting technically precise versions of reality may appeal to me and a few others but won't get us on the cover of Rolling Stone.

EOS Bodies / Re: New high resolution camera
« on: November 12, 2013, 02:42:01 AM »
..but the corners are always going to be crap regardless. Buy a Nikon 14-24 and the necessary Canon adapter, and slap that on your ultra high res FF camera to extract the most you can from the sensor, and push that final output resolution as high as possible.

FWIW - I use the 14-24mm Nikon on a D800 on occasion, it's kind of impressive.  but the corners aren't so great for sure, lots of CA and a bit soft.
Really want wide angle high resolution, try the 14mm Samyang prime instead. It's better in the corners at 1/4 the cost.

I'd also like to see DxOmark publish more lens tests using the D800e, the regular d800 is well covered, the e is only published with a few lenses.  AA filter on the d800 is weak but still there vs the e model.

Subjectively comparing center resolution from my long gone 5d2 and 70-200L f/2.8 IS 2 with my d800e with 70-200 f/4 VR Nikon does seem to give a small edge to the Nikon combo but the Canon pair was also providing extremely good detail, especially when using DPP to process it. They'd be hard to tell apart on the same shot, printed at 36"

Third Party Manufacturers / Re: Appeal of Nikon Df
« on: November 12, 2013, 02:20:32 AM »
I suspect the Df is one Nikon body the price might actually drop on in a shorter time frame because of the lacklustre sales.
If it does, I'll be ready to pounce if I still have a paycheck by then.

I've always had a sodtspot for pentax, love their choice of pancakes.  The k-01 is a great looking design too, canon could use some of their design verve.
I thought it was the oddest looking thing when I first saw it.
But once I got it in my hand I found it surprisingly comfortable to use, simple basic controls and soft-controls for many other functions were easy enough to access.  Still haven't had to look at the manual for this one.  The rubber flap on the right side is a bit lame tho.  Fits OK on mine but far too flddly.
A nice, sealed, latching door would have been far more appropriate for a "designer" object.

Lenses / Re: How many megapixels can these lenses resolve?
« on: November 12, 2013, 02:12:23 AM »
The simple answer to your question is as follows:

for any given region of interest, use the table of numbers of LW/PH

take that number, square it, multiply by 1.5 for the 3:2 aspect ratio
divide that by 1,000,000 if you want simple MP and you'll get the equivalent resolution if that portion of the measurement was uniform for the whole frame.

e.g.  center of 17-40 @ f/8 will = ~ 16MP

it's pretty sad when you calculate the corners!

If you measure the top level of the graph, ~3700, you'll get ~21MP which is the MP of the sensor in that body.

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