A580 vs A55 resolution

[Greg Beetham]

Yeah one does wonder what's cooking in the 7 realm, that should be interesting when it unfolds, I haven't seen a murmer even so far.
Greg

[OneGuyKs]

You should care because I don't agree with you..and unlike some folks I'm absolutely staggered you feel the need to run a whole scale marketing campaign for Sony on this and other forums..

A55 has superior handling and IQ than Kx. The resolution is same as A580 according to the sites that tested the resolution. A55 is class leading. Kx is not. Move to Pentax forum with your Pentax marketing campaign. It's there somewhere on the web. Use goggle.

[OneGuyKs]

At lower ISO, A55 (despite the mirror) has better sharpness and resolution than K-5. This was confirmed even by photozone owner. He is sending K-5 back

http://forum.photozone.de/index.php?/to ... 5-ordered/

First impressions:

The JPEG quality is terrible (in terms of pixel-level-sharpness).
The RAW quality is Okayish - 25% blur - which is significant. Based on these initial tests I'd conclude that it has a rather aggressive AA filter.

The max. LW/PH are barely higher than the ones of the K10D. So far for the fanboy criticism that I should have migrated earlier ...

Chief Editor
photozone.de

This confirms what we saw on IR samples (A55 at base ISO is sharper than Nikon D7000 and K-5).

A55 left

[bfitzgerald]

A55 has superior handling and IQ than Kx. The resolution is same as A580 according to the sites that tested the resolution. A55 is class leading. Kx is not. Move to Pentax forum with your Pentax marketing campaign. It's there somewhere on the web. Use goggle.

Actually as you are such a fan of DxO I thought you like to see their results:

Capture.JPG

(49.41 KiB) Downloaded 1825 times

Almost identical (and with a margin of error could swing either way) thus by your own faith in DxO you're simply being economical with the truth by slamming IQ. Then the fact the price between the two models isn't even close (well over £200 cheaper for the K-x) you tell me what's a good deal or not depending on your needs?

As you have so few customisation options you are forced into menu diving on the A55, when you can simply set it up how you want on the Pentax. You can't set the Auto ISO limit, you can't set the NR very low on Jpegs leaving with smeared jpeg output on the A55, can't calibrate the LCD, no ISO in the VF even with the EVF (an astonishing oversight), no P shift..the list goes on.

But again I'll go back to the topic. Translucent is compromising IQ in a small way..and the camera is better without the mirror.

[OneGuyKs]

Dxomark does not rate resolution. It rates noise and DR. K-5 resolution is far worse than A55, despite no mirror. K-5 resolution is below average. The jpegs are outright crappy according to Klaus, the reviewer at photozeone. IR images confirm this.

In fact, IR resolution chart shows that A55 scores higher for resolution than Canon 7D.

http://www.imaging-resource.com/PRODS/E ... MAGING.HTM

"Our laboratory resolution chart showed the Canon 7D's images with sharp, distinct line patterns down to about 2,100 lines per picture height horizontally and 2,000 lines vertically. Extinction occurred at about 3,100 lines in both directions"


http://www.imaging-resource.com/PRODS/A ... MAGING.HTM

"In camera JPEGs of our laboratory resolution chart revealed sharp, distinct line patterns down to about 2,200 lines per picture height in the horizontal direction, and about 2,100 lines per picture height in the vertical direction. Complete extinction of the pattern didn't occur until about 2,800 to 3,000 lines."


There goes your theory down the drain. A55 beats 7D for resolution. Where is your mirror theory now? I guess time to move to Pentax forum.

[bfitzgerald]

I'm sure ebay is flooded with Canon 7d's as owners desperately offload their "awful camera" in order to get hold of the amazing A55. Back in the real world you have still failed to admit that the mirror does impact IQ. As you linked to the site and they clearly show less resolution and light with the mirror in place..you will have to admit defeat on this one. Even if Sony are playing around with the AA filter..Translucent does compromise the IQ because it would be even better with no mirror.

And no mirror is the ultimate design goal thus SLT is here only until they can work out how to do fast AF without it.

Nowhere to hide on this one you'll just have to accept translucent does influence IQ.

[OneGuyKs]

I'm sure ebay is flooded with Canon 7d's as owners desperately offload their "awful camera" in order to get hold of the amazing A55. .

Your theory has gone down the gutter. The 16 MP A55 scored higher than the 18 MP Canon 7D on IR resolution chart. How did that happen? I thought 7D had no mirror? Shouldn't 7D score higher on resolution since it has no mirror? You told us it would, but it did not. Why is that? I wonder why K-5 has crappy pixel level sharpness -- worse than A55 -- despite no mirror? Too bad Pentax has crappy jpegs, but K-5 resolution is even worse in RAW (photozone). That's kind of sad since you just switched to Pentax

(ok, that ranting is fun).

[OneGuyKs]

So here (left) A55 and right K5. Where is that resolution and contrast advantage that according to you K5 must have since it has no mirror? Can you point to it. Put a finger on it?

[Greg Beetham]

But there are differences on those 'charts' the A580 has cleaner lines than the A55 and the extinction is much further along as well, so the A580 looks better, not by as much as I would have expected though.
Greg

ps. Here are some DxO results.

A55D7000K-5-compare.jpg (98.01 KiB) Viewed 3756 times

[OneGuyKs]

But there are differences on those 'charts' the A580 has cleaner lines than the A55 and the extinction is much further along as well, so the A580 looks better, not by as much as I would have expected though.
Greg

Yes, in "those charts" but in other charts A55 scores higher than A580

http://translate.google.com/translate?j ... 24425.html

"The image resolution is high, even higher than the Alpha 580, Which uses the same sensor and high in the ranking sets the image.""


Dxomark has nothing to do with resolution and contrast at lower ISO, so I don't know why you guys keep posting it. The topic is resolution.

[Greg Beetham]

The overall score by them is relevant right accross the range. I saw that translate.google one before, I think I'll wait for someplace like DxO to give an opinion on how the A55 compares to the A580, also David has an A580 on order so we'll hear from him in due course also. Till then remain calm folks, we aren't trying to torch the sacred cow, just get the facts.
Greg

[OneGuyKs]

The overall score by them is relevant right accross the range. I saw that translate.google one before, I think I'll wait for someplace like DxO to give an opinion on how the A55 compares to the A580, also David has an A580 on order so we'll hear from him in due course also. Till then remain calm folks, we aren't trying to torch the sacred cow, just get the facts.
Greg

Once again dxomark does not score resolution. How many times do I need to repeat it? Am I speaking English? Of course A580 will score higher on dxomark. Dxomark score is based on noise, and A580 gets 1/2 stop more light.

Read the topic of this thread. It says resolution -- at base ISO. That's the topic. A580 doesn't score better resolution at base ISO. That's the topic.

[Greg Beetham]

Once again dxomark does not score resolution. How many times do I need to repeat it? Am I speaking English? Of course A580 will score higher on dxomark. Dxomark score is based on noise, and A580 gets 1/2 stop more light.

Read the topic of this thread. It says resolution -- at base ISO. That's the topic. A580 doesn't score better resolution at base ISO. That's the topic.

That's ok, the A55 is good at base ISO, got it, you use base ISO a lot then? seeing as how it's so important apparently.
Greg

[Scooterman]

All this Lab testing proves absolutely nothing in the real world; it is how the camera performs in use.
The only criticism I have of the A-580 so far is the sharpening of the Jpegs, ok if you want to do nothing with the image apart from printing it, it is fine and a very good attempt in that area.
Regards
Richard

[peterottaway]

Once again dxomark does not score resolution. How many times do I need to repeat it? Am I speaking English? Of course A580 will score higher on dxomark. Dxomark score is based on noise, and A580 gets 1/2 stop more light.

Read the topic of this thread. It says resolution -- at base ISO. That's the topic. A580 doesn't score better resolution at base ISO. That's the topic.

That's ok, the A55 is good at base ISO, got it, you use base ISO a lot then? seeing as how it's so important apparently.
Greg

Well actually Greg my A33 was set to EI 200 and -0.3 and is now on EI 200 and - 0.7. I suppose I will try it indoors at EI 1600 and no fill flash with a few group shots over Christmas. Or perhaps if I go to indoor hockey when it resumes in the new year.I find I usually have no more reason to go over EI 800 than I did with film.