*ist DS Test in AP


Malcolm Riches

Link Posted 19/02/2005 - 05:27
Amateur Photographer's test of the *ist DS commented on a lack of sharpness. I sent this letter to AP, but have yet to see it published. What do the readers of this Forum think? Here is my letter ....

Thank you for the test of the Pentax *ist DS. I was very pleased to note that your comment on edge fringing was qualified by the lens used - the consumer standard 18-55mm lens having a small problem. Is this also not the case when it comes to the softening of images? I have the *ist D and noticed soft images when using the previous standard lens, the 18-35 FA-J. But after I had invested in the Pentax 16-45mm ED-AL lens the improvement in definition quality was very noticeable and well worth the extra cost. Could you do a quick comparison using a better quality lens to see if it is the consumer lens, or the noise-reduction algorithms, that are the main cause of your disappointment in image sharpness?

Any first hand experience?

Malcolm

johnriley

Link Posted 19/02/2005 - 12:01
Sometimes I wonder when AP will find a DSLR that they actaually like, but then they did like the Nikon D70 and the Canon !DS II, so I guess they do sometimes....

I found the 18-55mm lens to be very good, amazingly so for its price. Very sharp, low flare, good contrast and virtually no chromatic abberation. I haven't tested the 18-35 we bought from you via eBay (!) because Sue is using that on her *ist film camera.

I have also been using a SMC Pentax-A 35-70mm in the studio with studio flash. This has been equally excellent for portraits and I'll be posting some of those on ePHOTOzine over the next few days, starting at some ludicrous hour early tomorrow morning.

I did notice that the AP review was mostly complimentary, although I felt reluctantly complimentary...They praised the low noise levels, but then the headline on the pictures was a negative comment about noise at 3200 ISO. Very inconsistent approach.

I'm actually quite pleased that the *istDS does not over-sharpen in camera, and I have found with a modicum of USM (around 50%) the pictures crisp up beautifully.

The only thing we don't know is how this relates to the type of photography that we take, and it may well be that someone else would not be as pleased as I am. But I certainly have no complainsts about the *istDS.
Best regards, John

Malcolm Riches

Link Posted 19/02/2005 - 17:00
One point I am trying to make is that the testing of a DSLR needs a different approach to that of testing a film SLR.

Tests on a film SLR body do not normally comment on the sharpness of the image because that is down to the lens used and, to a lesser extent, the film.

However, tests on a DSLR comment on the sharpness of the image because the sensor (replacing the film) is an integral part of the camera body. But what about the lens used? Surely this must be the major factor in establishing how sharp the image will be ..... but the lens is not on test, only the camera body.

My argument is that when DSLRs are tested, the type and quality of the lens must be an integral part of the assessment.

I think AP now realise something along these lines as the early tests of DSLRs commented on fringing, making no reference to the lens used. At least in the test of the *ist DS the slight fringing experienced was seen as conditional upon the lens used, and not solely as a defect of the sensor.

Should the same thinking apply to sharpness? That's my question.

johnriley

Link Posted 19/02/2005 - 19:00
I suppose in film photography we are always shooting at the optimum resolution, only limited by the film used. But in essence it is always the best quality.

In digital cameras it depends on not only the lens, but how this interacts with the sensor and again how we save the images (RAW, TIFF or JPEG) and at what resolution. Although I always shoot at the highest resolution, just in case the image is one I want to put to some other use.

So, for example, when copying a monochrome magazine image, my Fuji S7000 needs to be set to monochrome, or the structure of the printed image causes interfernce patterns with the SuperCCD. I don't know if the Pentax sensor is better in that specific circumstance because I haven't tried it yet. But the point is that the sensor structure has a serious effect on the final image and needs to be matched to the lens.

As for the *istDS, I have tried M lenses, A lenses, F lenses, FA lenses and DA lenses and to be honest they have all given excellent results. Obviously some will be better lenses than others, but that would have been as true on film.

I think the difference lies in the much larger CCD, which does not have to pack tiny photo diodes so tightly as the Fuji (for example) does. The result is an incredibly clean and sharp image with very low noise.

I think I'm sort of talking around your question to an extent, but perhaps the thoughts will prompt some other responses?
Best regards, John

cliff_occo

Link Posted 22/02/2005 - 13:43
I think we need to face the fact that AP. like everyone else, has a 'down' on Pentax generally. It seems to me that unless you are wearing a Canon or Nikon around you neck (so far as SLRs are concerned) you aren't taken seriously. I am concerned that Canon spends a heck of a lot of money promoting competitions (eg APOY, Digital Photographer of the Year in Digital Photo) and appears to arrange a lot of product placement on TV etc. AP loved the top of the range Canon DSLR (EOS1Ds?), costing as near as dammit 6K for a body alone - and I wondered what an amateur camera mag was doing reviewing a piece of kit costing such an obscene amount of money.

Digital Photo also did a 4 way comparison(*istDS, EOS300D, D70 and E300) in current issue. In the image comparison the Pentax gets the lowest score, yet to my eye the images are on a par with those taken with the Canon, which got the top score, and better than the D70 which got a higher score!

I posted remarks like this in a general photo forum of which I am a member and got howled down, being told that 70% of photographers at (I think) the Olympics used Canon. So what? They would have been using top of the range models with lens costing 2K+ - and I'm certainly never paying that kind of money for glass

Malcolm Riches

Link Posted 22/02/2005 - 14:13
Many thanks for your comment. I must admit that I have not felt a similar bias against Pentax.

However, in the 4 way test you mentioned, was any mention made of the lenses used with each camera?

My argument is that digital image quality is a combination of the lens used AND the sensor .... and that the quality of the lens is ignored by the testers.

cliff_occo

Link Posted 22/02/2005 - 19:59
'However, in the 4 way test you mentioned, was any mention made of the lenses used with each camera? '

Yes. Interestingly enough, they say they used a Sigma 18-50mm f/3.5-5.6 DC and 55-200mm f/4 - 5.6 DC in each case (+1gb Sandisk Ultra 11 card, for what that's worth)

I suppose using an independent lens is a not unfair way of conducting a comparative test.

Malcolm Riches

Link Posted 23/02/2005 - 03:29
That's good news and makes sense. Thanks for the information.

Pete Bargh

Link Posted 23/02/2005 - 07:31
The *ist DS has just been tested in a head to head alongside the Olympus E-300 in Digital Camera Buyer and it won...five stars
Publisher
Magezine Publishing Ltd

cliff_occo

Link Posted 23/02/2005 - 10:41
I've been thinking overnight, and am not sure, as said, whether this 'does make sense':-

'Yes. Interestingly enough, they say they used a Sigma 18-50mm f/3.5-5.6 DC and 55-200mm f/4 - 5.6 DC in each case (+1gb Sandisk Ultra 11 card, for what that's worth)'

If the review is intended as a consumer review it seems to me (after thinking about it in the 'wee' [with two meanings to the word!] small hours), then to use independant lenses is flawed. Buyers will fall into two categories:-

(a) existing users of fim SLRs of ther four brands referred to - in which case they will already have a supply of lenses and will unlikely want to buy an independant lens, ignoring the Olympus which, of course, is a different matter, and I guess buyers of that will be similiar to:-

(b) 1st time buyers of SLRs who are likely to buy the camera (of whichever make) in kit form anyway

There is a third catergory, like me, who, whilst having a number of lenses, brought the kit lens because of its wide angle capabilities, knowing I would loose on my existing due to the focal length shift.

johnriley

Link Posted 23/02/2005 - 13:15
In days gone by, a camera test meant that and was very extensive. Shutter speeds were checked, lenses were checked for resolution and other properties, in some USA magazines the cameras were even partially dismantled to check on design and manufacturing quality!

Now we don't have tests, we have reviews, in the main anyway.

The various points that have been raised in this thread are, I think, good ones. You could argue though that the use of an independent lens was flawed in itself, because it isn't matched to any particular CCD and therefore might favour some at the expense of others. Or if it were matched to a popular brand then that too could be unfair.

So perhaps the fairest test is to use the lens supplied by the camera manufacturer, on the basis that it is what they are selling to us, and presumably what they want to be judged by?
Best regards, John

Lurach

Link Posted 23/02/2005 - 21:48
Yes John, I agree with you on your comments regarding "tests" and "reviews".

I remember reading the tests in Practical Photographer all those moons ago. Sometimes the descriptions of the "rigs" used to test the various aspects of the body/lens under scrutiny was an article in itself. By the time you finished reading the test, and the details of the instruments used to measure each aspect, and the accompanying graphs and charts, you felt that the only thing missing was a "credit" stating that the test had been performed in NASA's, or the Atomic Energy Commission's laboratories or some other such august facility

If my memory is correct even details such as shutter speeds were often somehow actually measured for accuracy.
Lurach

Anonymous

Link Posted 24/02/2005 - 01:41
I totally agree, once upon a time a camera or lens test would give you all the info you needed to do head to head comparisons yourself, and at the end a breif opinion, it was reviews like these that encoraged me to stick with pentax because oflens quality, these days they are just reviews or worse "infomecials" but then this was also a time when if you perchased pentax nikon canon or olympus you got a pro lens there was no double standard thats why k m and a series are legendary.

johnriley

Link Posted 24/02/2005 - 04:38
Photography has also changed - at one time it was more a specialist hobby, with 16" x 20" black and white prints being produced at home. Although some still do this, it is not now a major requirement.

Colour slides also need good lenses when projected to enormous sizes. How many pjotographers shoot transparency film?

The order of the day has been the 5" x 7" (or smaller) clour print, and the market has become mor universal for the SLR. You don't need a brilliant lens to take low grade photographs, and some makers may prefer to compete on price instead.

The professional market is something else, and professional lenses will reflect the price levels that we probably ought to be paying for the quality we want.

However, digital changes things yet again, although, ironically, the lenses on some SLR style and even compact style digital cameras are incredibly good, presumably easier to make for smaller image circles. A3 prints can easily be made, and of course on screen pictures look great at much lower resolutions.

I don't think much is manufactured that is better than it needs to be for its market!

Finally, I am very fond of the K, M and A series lenses, and still use them routinely. They will produce large prints and fantastic slides with no problem at all!
Best regards, John

Anonymous

Link Posted 24/02/2005 - 08:15
Yes, I suppose the market was a different place then, cameras were produced by companies whose only business was "photography" and new models were a major event rather than an annual, or more frequent, expectation.

And with reference to slide film, I did recently run off a couple of rolls of slide - possibly the first in about ten years though!!!

Now none of us, I assume, would begrudge the advances and advantages brought about by the development of autofocus, digital and other forms of electronics now incorporated in our cameras. But while I revel in the marvels and advantages of my *istD, like yourself I suspect, I still love my older gear. (I once traded in an MX body and matching 135mm lens when upgrading and still haven't quite forgiven myself - what a lovely little body, and indeed lens.) Now I prefer to simply hold on to the "old?" gear rather than dispose of it.

Who of us, who have used them, can forget the "feel" of the likes of an MX, Super A or LX in the hand. The feel of the thumb resting between the body and film advance lever in anticipation of the quick "grab" sequence or the way the body was carefully rested in the palm of the hand to allow a smooth fluid movement of the focus ring. (Has autofocus even changed the way users hold a camera now?? )

Among my lenses I have a 50mm 1.7 A series and I still look on its "visual" attributes almost as a piece of art in itself - I know, sad really, but the doctor says there is still some hope of recovery
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