Sony alpha A55

[OneGuyKs]

In his latest post he said the problem was with the Tokina lens. The photos were out of focus at 70mm F2.8 even when he tried at home with cold camera. No problem wit the camera but with the lens.

[mike2008]

yes the OP had a second day shooting and got 400 shots with no overheating sign, but the camera did get hot.

It sounds like the nex, which isn't really surprising.

On another subject there are some nice shots here from the a33 showing a distinct lack of the aberrations which were being attributed to 'ghosting'. Some of the shots look like they really ought to be showing some effects, but they don't seem to be there. I still do not understand what was causing the double image in the dpr test shots. Perhaps the light has to be even more saturated to produce a ghost. Perhaps it was all due to a filter or lens effect.

http://www.sonydslr.com.tw/alpha/viewto ... =9&t=41514

[Greg Beetham]

Wasn't 'that' image with them at 100%? if it was, the lights on the this bridge might be too large to show the effect..not pointy enough maybe, there is still what looks like funny stuff though, the green light has a peculiar blue blodge just to the right of it, and some of the windows look like they have some sort of half reflections under them, but strangely not all do...hmmm
Greg

[mike2008]

i think the point is that the ghosting is not really a big deal at all. Perhaps you can find it if you're really looking, and you have some saturated highlights in your image, but it's at the 100-200% pixel level and even then not realy detracting any more than the myriad issues produced by all the other optical elements in the imaging system; if you look closely enough you can always find something, particularly if a shot is poorly exposed.

There will always be people who see a camera which has great IQ and features but whose images can occasionally have a tiny aberration and get upset. The A55 is not for them - I wonder if any camera would be. For everyone else the advantages of the SLT design seem to be really very nice, and allow sony to agressively price these models while leaving room for OVF-based cameras.

For what it's worth dpr have just updated their review of the A55, giving it a strategic 1% lower score than the 550D, and saying

"Since publishing this review we have taken the opportunity to investigate the much-discussed 'ghosting' effect of the A55's semi-transparent mirror. Our conclusion - if you know where to look for ghosting, you might find it on close examination, but we don't consider it to be a problem in the vast majority of 'real world' shooting situations."

Which sounds pretty reasonable and in line with what I've seen so far.

I'm sure some will continue to fan the flames of this issue, but for me it's concluded.

[Birma]

I think it was a good idea for DPR to update the review and the result seems quite balanced. I am really looking forwad to being able to to see an A33 or A55 in the shops, hands-on, and to compare the "feel" of it against a Nex 3 or 5.

[bfitzgerald]

Whilst I don't think the Ghosting is a massive issue, we're still at the same point as before. And that is having a fixed mirror brings disadvantages as well as advantages. For the no compromises crowd (ala light loss, and ghosting) they'll likely dismiss these fixed mirror models. Maybe most folks will be happy enough with them.

Long term though I stand by my point that in order to fulfil the overall concept of these cameras (ala EVF, smaller faster FPS etc) that these are merely a stop gap solution until the technology allows the removal of the mirror altogether. I see these models aimed more at non enthusiasts overall the design and layout is very p&s user based. And still nobody responded to my question about how to change the AF point? I can now fully understand why for stills photographers the SLR is based around a moving mirror and not a fixed one, there are no compromises to IQ whatsoever. It's a superior solution for most photographers.

I'm still as uninterested in these now as I was then. Also puzzled how the ghosting escaped the attention of the DPR review team

[Greg Beetham]

I still have a concern about any camera of this type with all those extra power consuming features, and that is battery duration.
I recently went on a trip far from civilization for about 9 days and took a couple of old cameras, (but both have less than 4000 shots up) a KM5D and an A100 both with a spare battery each, I used the KM5D mostly and took quite a few photos, (for me that is, somewhere between 250 and 300 at a guess, it was primarily a fishing trip not a photographic trip), probably about three times more than on the A100. I was still using the original battery in both cameras on the trip home, the KM5D one needed charging the day after I got home, the A100 battery was still at about 65%, but it went on the charger also. If I had taken my A700 in lieu of the KM5D I'm pretty sure I would have used the first battery and the reserve for it would have been at low ebb as well. There was still an option it the destination too use a charger in an emergency, but that would have entailed running a generator or running a vehicle fitted with an inverter for a lengthy period...maybe a solar panel might be another option... didn't have one of those though.
So this leads me too the A33-A55 battery question in the same circumstances, how many batteries would one have to take 'bush' in order to have a functioning camera the whole time? as in the above example.
Greg

[mike2008]

It's interesting to me that there are some people who always nitpick about IQ etc., and yet 5 years ago they were perfectly happy with their low-resolution poor jpeg converted slow dslrs. And before that with film, and all it's challenges, costs and drawbacks.

I'm not saying the A55 is perfect or even optimal. The question I have is: what would you like to do that it doesn't let you do...

If you print up to A3 size the resolution is fine, even probably a bit higher. There are some amateur photogs who need more, but they would be looking at a FF camera. If you are a pro sports shooter it isn't ideal, but it's price is much lower than a sports body.

I agree that the A55 is not perfect. I don't think it matters, after a certain point, certainly not in terms of photography. In terms of ego and showing off it might matter a lot, though...

To sum up:
Compared with what we had a few years ago the A55 is light years ahead, in terms of low-iso IQ, high iso IQ, DR, fps, focussing, exposure, live view, size of viewfinder etc. There are spectacularly few things that cannot be done easily and well with the A55. Add to this, it's very compact, very light and cheap.

I totally understand why some don't like it, they prefer a bigger body, weather sealing or OVF. fair enough. but as a pure photography tool the A55 would be more than sufficient for most peoples needs.

It certainly marks a major step forward in terms of Sony's offering, and is the most competitive camera they have ever produced, imo.

[bfitzgerald]

I agree it is the most competitive camera they have produced but then you have to look at previous efforts. A230/330/380 pretty much mocked from day 1 on the market and worse then the models they replaced. A290 and A380 change nothing bar the sensor (still CCD no CMOS) and address the grip issues and none of the handling or feature crippling points. Conclusion entry level Sony Alpha is completely outclassed and not even as good as their 2008 model range.

A450 seems to be selling pretty cheap on a firestorm sale which is fine as it's really an entry level DSLR anyway. A500/550 were ok but really not as impressive as they should have been again Sony are stock clearing on these ones. If we're honest the A450/500/550 are what the real entry level models should be (perfectly decent at that price point)

So yup I agree most impressive so far but then for £750 odd for the A55 and £650 both with a kit lens they should be half decent right? I could actually get a K-7 and kit lens for slightly less (a true semi pro body) or a D90 etc or even a Canon 50d (body only)
Sooooo what would folks get? I know I'd rather buy a semi pro level body (or near there) for my money than a nice but consumer geared EVF model.

Still we'll soon see how they do in the market. I applaud something different in the market, just a shame they forgot about OVF users!

[mike2008]

Still we'll soon see how they do in the market. I applaud something different in the market, just a shame they forgot about OVF users!

Well, they did introduce the A580 as well.

Next up, A750... hopefully.

I know that many people are worried about sony potentially pulling out of the ovf style dslr, but I think those concerns are really premature. With the probably large input of new users coming to sony with these fresh cameras it makes more sense than ever to flesh out the top end.

If they did have a competitive OVF-based A750, and EVF-based A77 as well as an OVF-based A950, and EVF-based A99 they would really have a complete line up, and people would start to take them a lot more seriously. Until I hear otherwise this is what I assume they will do.

[Birma]

So yup I agree most impressive so far but then for £750 odd for the A55 and £650 both with a kit lens they should be half decent right? I could actually get a K-7 and kit lens for slightly less (a true semi pro body) or a D90 etc or even a Canon 50d (body only)
Sooooo what would folks get? I know I'd rather buy a semi pro level body (or near there) for my money than a nice but consumer geared EVF model.

Or you could get a Nex 5 twin lens kit and have enough left over for a couple of spare batteries

It always surprises me to see how much cameras reduce in price. The K-7 and 50D were both over £1000 when they were released (see http://camerapricebuster.co.uk/index.html). The K-7 has come down a lot in just over a year - looks a very good deal if you are going for a Pentax. I suppose the A7xx (?) will be over the £1000 when released. Interestingly the D90 price has been far more stable - I suppose the mark of a successful model.

[bfitzgerald]

Fair point both were over £1000 making a good case for the "wait for the inevitable price drop over time"
Guess it comes down to where the A580 ends up price wise can't say I'd shell out it's pre order price but for £500 might be worth a peek.

D90 has not come down as much. But this will be very interesting as Nikon are said to be making the next D90 higher up the scale and costlier too. Wondering where they will put a new D5000 probably where the D90 is about now I would think. There is no doubt the D90 has been a rock solid seller for Nikon dated or not it's held ground well and sold strongly since day one. It's these kind of meaty models that Sony lack..and that alone shows a photographer based camera can hold it's own and sell very well over a longer period of time.
I keep hearing Pentax are working on some nice stuff too, so we can't really judge how Sony stack up until we see what rivals have to offer.

[Greg Beetham]

Maybe the rinky dink new fangled A33 and A55 have better image IQ than a KM5D but if you run out of batteries it won't matter how good it is, it's a paperweight. Besides how many people in the consumer bracket print at A3? The KM5D has more resolution than my 24" screen, it exceeds the resolution of my photo printer at A4 by a big margin, and how big can one post a photo on the internet generally? taking this forum as an example, where the limit is 1000 pixels on the long side.
The ONLY advantage of having HUGE image files is to do cropping, but if you become used to composing the photo better in the first place cropping is not nearly as necessary any more.
Greg

[twm47099]

I keep reading that the A55 has better IQ than the xxx. But now I'm not quite sure.

After I read the dpreview ghosting analysis, I tried to examine some of their shots to see if ghosting was an issue in "real" shots. I was not impressed with the ghost examples from the night time city shots because of the mist or glare that caused more aberrations than the ghosts. Dpreview had shown the crop where the building wall was overexposed and there was a ghost image to the side of it (photo taken in portrait position), and the conclusion was that ghosting would only be a problem with blown out highlights.

In my search, I had come to the conclusion that in the real world there weren't too many shots where ghosting would be a problem (astro shots most likely, and blown out large highlights for another.)

Then based on the conclusions in the dpreview I looked closely at the raw comparison studio scene page (I wanted to see how much better raws looked), and was very surprised.

The first thing I saw in the blow up comparisons was the bristles on the brush. They seemed mushier than those on the NEX. Confirmed, to a greater extent on the hair in the right side of the shot.

Then I looked at the cross in the center, the circle with radial lines, the white squares at the corners of the black box, and the Bailey's bottle. In all cases I saw what appear to be ghosting of the light areas (gold stripes on the bottle label) into the dark (light on top, black on bottom). I also looked at the resolution charts and ghosting of the white background into the tops of the black squares was also apparent.

This post on dpreview includes the cross and Bailey's bottle comparisons between the A55 and NEX:

http://forums.dpreview.com/forums/read. ... e=36259121

The effect of the ghosting was not obvious double images, but were dim extensions that that lowered local contrast and consequently lowered edge sharpness. When comparing the A55 v the NEX, the NEX was definitely free of such artifacts (as could be expected) and had noticeably sharper edges. I also compared with the A550 and the A550 was significantly sharper (hair) and obviously didn't show any of the ghosting/shadowing. I am wondering
if each contrasty border with light on top contributes a small "bleed" that reduces local contrast, even when the contrast difference is not enough to cause a easily visible ghost, and results in an overall apparent reduction in sharpness?

I did download the jpgs of the crops shown in the link and tried to sharpen them in PSP12. With the NEX shots, it worked as expected - Unsharp mask for local contrast enhancement (wide radius, low intensity) made the image pop. And all of the sharpening methods (sharpen, sharpen more, unsharp mask and high pass filter all had the expected effects). With the A55 shots, local contrast enhancement increased the contrast, but made the band more obvious. The other sharpening methods essentially did not help the sharpness of the edge (light on top dark on bottom), but helped the other edges. So I wasn't able to find an easy way to correct an entire image. Maybe there are other techniques that would work better??

I don't know how significant this is. All the dpreview comparisons are at 100%. Not everybody buys CZ or G lenses, so not everybody cares about ultimate sharpness. I doubt it will have any effect on video. But I certainly can't say the IQ of the Axx is better than xxx.

Comments please. What am I missing (other than the obvious that some people don't care about sharpness).

thanks
tom

[mike2008]

To greg: Guess you're lucky you don't want a high res camera, there's plenty on the market. Remember though even the new ones can take low res jpegs if you like. I agree that longer battery life would be nice, but on the other hand icarrying an extra battery or two isn't such a big deal if you're happy with a camera.

To the poster above: vertical resolution tests are probably a decent discriminant for whether there is bleed from the internal reflection of the semi transparent mirror in well-exposed images.

raw A55


raw nex5


It seems to me that the nex gets very close to the Nyquist limit while the A55 loses discrimination earlier, but thanks to the higher resolution of the A55 the absolute resolution cut-off is similar for both cameras, between 28 to 30. So it shouldn't be a big difference between the cameras based on this.

In the comparison shots you can without question find ghosting when you look for it:


The overall impact on resolution is not significant. The appearance of ghost images can be seen if there is a greater than 8EV contrast between adjacent pixels. Whether this real but pixel-level effect is inconsequential or not is user-dependent. The important thing it to be aware of it, and we are all aware of it now.