Focus Problem with S2?

[Philbert]

I purchased my Fuji S2 Pro at the first of October this year. At the same time I purchased a new Nikkor 24-85mm f/2.8-4D AF Zoom Lens. I have discovered that images taken at low f-stop values are consistently out of focus. In order to confirm the nature of the problem, I took some test photos using playing cards. The test images are located at http://www.wendiphoenixphotography.com/Focus. The cards are spaced just under 2 inches apart. The image 59mmAFf3_8.jpg was taken using single Auto Focus mode and the image 59mmMFf3_8.jpg was taken using Manual Focus. In both cases, the shot was made on a tripod with the zoom lens at approximately 59mm and the aperature set at f3.8. I focused each shot with the viewfinder's center focus target over the large spade symbol on the ace. As shown, the actual point of focus is somewhere behind the desired point of focus. The issue I'm faced with now is to determine the source of the problem, is it the camera or the lens? Also, what should I expect to see in this type of test shot? I have always believed that for a given focus setting, one third of the depth of field should extend in front of the focus point and two thirds behind the focus point.

Any help you can give me would be appreciated.


Philbert

[Philbert]

Sorry,

I ended the url in my post with a period. Correct url is:

http://www.wendiphoenixphotography.com/Focus

Philbert

[Tom V]

Philbert,

I could not open the links you provided.

If your lens makes a sharp image anywhere, the lens focuses, and the camera should be able to autofocus provide the subject is appropriate. The camera does not detect that a subject is 5 feet away and then turn the lens to 5 feet. It focuses by judging light contrast on the chosen focus sensor. When it detects the highest possible contrast, the image is as focused as it's going to be.

I suppose some lousy home-built Coke bottle zoom lenses that have the ability to focus at two or three distances at the same time, each on different wavelengths and distortions - could give a autofocus unit a hard time.

If the camera cannot focus the image sharply, it is the camera (or user) at fault. If you have the camera autofocus on a certain point but the image is focused somewhere else, I would say it the camera is not focusing correctly.

The camera focus sensors cannot focus on a subject that has no detail or lacks contrast on which to focus. Perhaps the black spade symbol on the cards you were shooting had no detail on which to focus. The camera cannot focus in very low light conditions or in low contrast conditions. Very high contrast conditions can also fool the focus sensors. Shooting through screens, dirty glass or plexiglass, diffusion or fog filters, etc. can hinder autofocus operation. Using a teleconverter that raises the effective maximum aperture past ƒ5.6 can be detrimental or cause autofocus not to work at all.

I owned a camera (Minolta X570) which had a loose focusing screen. I could focus manually on the screen and the resulting photos would be out of focus. I noticed that subjects on the left could look in focus and equidistant subjects on the right would look out of focus. Reseating the focus screen fixed everything (until I jarred the camera again).

Perhaps your individual S2 has a loose or misaligned focus screen or auto focus sensor array?

The focus screen's focus area indicators might not be exactly aligned with the precise area that the focus sensor reads - they might be off a millimeter one way or another. which is not ideal, but common among all brands.

At a halloween party last Saturday, my camera had a hard time focusing. My subject was two people wearing white (a ghost and Mr. Clean), sitting on a white couch in a dark room, next to a hyper-active fog machine. It gave my focus sensors a workout. It was no fault of the lens. I had to focus manually, trusting my eyeball and relying on the inherent depth of field a 14mm lens provides.:eek:

[Philbert]

Tom,

Thanks for the quick response. My web host provider was having problems yesterday so I'll attach one of the pictures below. The picture was taken using manual focus (I focused carefully on the ace). The Auto Focus picture produced similiar results. In using the autofocus I was careful to include the spade symbol inside the center focus target with enough white space to provide good contrast. Based on your comments, I will contact Fuji to get a Return Authorization Number for a waranty repair.

Philbert

[David]

Hi Philbert

I too have been having focus problems.

I have tested the camera on a tripod and have had some interesting results. I photographed my wife leaning against a wall and I filled the central focusing brackets with her face making absolutely sure none of the wall was in the brackets! The resulting images were soft on her face with the wall in focus!

I then photographed her approximately 1 meter away from the wall and the results were that she was now sharp and the wall out of focus. Thinking that the texture of the bricks was somehow the reason for the first shots being sharp I then went into the house mounted my SB80DX Flashgun on the camera and positioned my wife against a plain painted wall. The results were exactly the same as outside, the camera had focused slightly behind her.

Using your shot of the playing cards for inspiration I photographed four cereal boxes staggered behind one another by approximately 4 inches. You can probably guess what happened, yes the camera focused on the box behind the one I had focussed on.

How have you got on with Fuji? Have they lent you a replacement camera whilst yours is being fixed? Are you a working professional? I couldn't manage without my S2 for more than a few days.

I await your reply with interest or anyone elses!

Kind regards

David (UK)

[jeffinkansas]

I am also having focusing problems with my S2. I have a 24mm fixed nikkor lens. I have tried the camera with a 28-105 tameron and did not find the same results. I am curious as to whether the make or quality of the lens contributes to the frequency of this problem.

Regarding fuji as tech support I have not had good relations. They have been rude and unhelpful. At one point they told my that a software specialist would call me in 10-15 min. Two days later I called them back, when I explained my distaste, waiting for nothing, they told me that I was not their only customer! dont tell me to wait around for nothing! Time is money

[David]

Hi Jeff

I am using the Nikkor 28-105mm f3.5-4.5 D lens and I don't think the problem is lens related. I think it is more likely to be a focus sensor problem.

Kind regards

David

[jeffinkansas]

David
thanks for your investigation. have you had any luck with fuji?

[David]

Jeff

No luck with Fuji yet. I spoke to technical support on Friday and they said that the S2 had been designed to be less sharp than the S1, because wedding photographers thought that the S1 was too sharp! Fuji's answer is to shoot with the S2 set to HARD and apply 150% 2 and 2 USM in PS. I think that they are aware that some S2's have a focus/sharpness issue and they are hoping that they can fob us off.

All the above was before I had done any testing. Now I have the results to prove there is a problem and it isn't my imagination I will contact them again probably on Monday 11th Nov. to see what they have to say this time.

Cheers

David

[jeffinkansas]

David

Many thanks for your legwork on this! Being new to digital and even newer to this camera I have gained an amazing apprieciation for forums. I also (as earlier vented) had a less than satisfactory interaction with fuji. I cant wait to hear how they deal with this one

Best of luck

Jeff

[Philbert]

David & Jeff,

Sorry for the delay in responding, I was out this weekend on a shoot. I'm a semi-pro who has been shooting since the early 60's and I am currently mentoring a younger friend (Wendi) as she starts her photography business. We are using my newly aquired S2 (which replaced an Olympus E-10) as our primary camera and have shot 1 wedding and a number of studio jobs with it. The focus problem first showed up on the wedding shoot while taking some existing light shots in the evening. We also noticed it on many flash shots taken in auto mode. Most of our studio shots are taken at higher f-stops so we don't see the problem there as often.

As to response from Fuji, I sent an e-mail with pictures carefully detailing the problem (same ones I've posted here) and received the following response:

" D L
11/01/2002 08:42AM

Good morning,

After further reviewing these images, please try the following.

Disable Custom settings 7 and 8. Set the camera to either manual or aperature priority and use F-stop 4 or 5.6 and up. Correct me if im wrong but the higher the number, the smaller the aperature. It is recommended to use a narrow aperature setting with this unit. The depth of field is shallower so smaller aperature (above F4.0) is recommended.

I will be attending Photo East Show in NYC and will not be in the office. However, I will be periodically be checking voicemail if you should have any further questions. Hope this helps.

Thanks.

D L, Digital Technical Supervisor
Consumer Information Service Center
Corporate Communications Division
1-800-800-3854"


After calming down, I truly believe that D L was just thinking out loud about the nature of the problem, and that "It is recommended to use a narrow aperature setting with this unit" is not meant to imply an official Fuji Corporate position that the Fuji S2 won't support low aperture settings on Nikkor Lenses. A followup call to Fuji has elicited a promise for a loaner camera to use while the problem is fixed. Wendi faxed the paper work in Friday, and I am waiting for the replacement to arrive.

If this is a wide spread issue, it may take a while to get a loaner due to numerous returns. I do wish that Fuji would give some sort of statement regarding the problem and it's impact.

As for the playing card stack up;
It was in an Olympus user forum that I first saw the card stackup used to show focus accuracy. When Olympus introduced the E-10, they had a similiar problem with many units exhibiting focus problems. After some amount of denial, they would finally accept that the camera had a problem and they honored their warranty.

Let me know how your dealings with Fuji progress and I'll do the same.

Philbert

[jeffinkansas]

Philbert

I am not sure what to say regarding the fuji response. Wow! I am curious as to whether the loaner produces better results. B/c I am curious whether this is a model production or design issue. Thanks for your contribution and I look forward to any further information you care to share

Jeff

[David]

Hi Philbert and Jeff

I am a working professional and one day a week I lecture at one of the local colleges. The college has just bought an S2, so today I have been runnibg some side by side tests not too different from your card test Philbert, but using Cereal Boxes.

I have tested my 28-105mm f3.5-4.5 and 18-35mm f3.5-4.5 Nikkors and the College's Sigma 28-70mm f2.8. I haven't had time to evaluate the shots yet.

I met a rep. from a photographic shop today who tells me that he has three customers with their camera in for repair at Fuji!

As to Fuji telling me that they have designed the S2 to be softer than the S1 sounds to me like a feeble cover-up. They say that wedding photographers said that they wanted the S2 to be less sharp because the S1 was too sharp. For year wedding photographers have been using Hassleblads and CarlZeiss Optics and softening the shots with Softars! Why couldn't this be done by the S1 users? I think that Fuji have made this up.

I have attached one of my earlier tests to show you my problem.

Cheers

David

[David]

Hi Philbert and Jeff

I am a working professional and one day a week I lecture at one of the local colleges. The college has just bought an S2, so today I have been runnibg some side by side tests not too different from your card test Philbert, but using Cereal Boxes.

I have tested my 28-105mm f3.5-4.5 and 18-35mm f3.5-4.5 Nikkors and the College's Sigma 28-70mm f2.8. I haven't had time to evaluate the shots yet.

I met a rep. from a photographic shop today who tells me that he has three customers with their camera in for repair at Fuji!

As to Fuji telling me that they have designed the S2 to be softer than the S1 sounds to me like a feeble cover-up. They say that wedding photographers said that they wanted the S2 to be less sharp because the S1 was too sharp. For year wedding photographers have been using Hassleblads and CarlZeiss Optics and softening the shots with Softars! Why couldn't this be done by the S1 users? I think that Fuji have made this up.

I have attached one of my earlier tests.

Cheers

David

[David]

Hi Philbert and Jeff

I am a working professional and one day a week I lecture at one of the local colleges. The college has just bought an S2, so today I have been runnibg some side by side tests not too different from your card test Philbert, but using Cereal Boxes.

I have tested my 28-105mm f3.5-4.5 and 18-35mm f3.5-4.5 Nikkors and the College's Sigma 28-70mm f2.8. I haven't had time to evaluate the shots yet.

I met a rep. from a photographic shop today who tells me that he has three customers with their camera in for repair at Fuji!

As to Fuji telling me that they have designed the S2 to be softer than the S1 sounds to me like a feeble cover-up. They say that wedding photographers said that they wanted the S2 to be less sharp because the S1 was too sharp. For year wedding photographers have been using Hassleblads and CarlZeiss Optics and softening the shots with Softars! Why couldn't this be done by the S1 users? I think that Fuji have made this up.

What size etc. would you recommend I save the images to ad as attachments?

Cheers

David

[Philbert]

David,

I downsized my images to 700 x 421 pixels in photoshop and saved to a .jpg file. I believe there is a 512K byte restriction on attachments posted here on the forum. My resulting file size was only about 37K bytes.

When you get your image sizing right, be sure to include aperture used, manual or auto focus and other lens information. I would like to see someone post a focus test image which demonstrates correct wide aperture manual and automatic focus registration with correct distribution of depth of field.

If Fuji is saying that they have softened image contrast (or even tweaked the gamma) in the processed jpg or Tiff output to appeal to Wedding Photographers, I might believe that. Intentionally throwing an image out of focus is another issue altogether. I don't know of a single photographer who would seriously suggest intentionally crippling a camera system to only produce an out of focus condition.

Most likely, the person you talked to has a piece of paper in front of them which says if someone calls complaining about image sharpness, contrast or gamma tell them we intentionally softened the image and here is how to get it sharper. The fix will probably raise the image contrast but cannot restore focus which was never present to start with. The important point here is to demonstrate to the customer service person that you are complaining about a focus issue and not an image contrast or gamma issue. Let them know you refuse to believe that anyone would design a camera which can not be accurately focused at low (or any) aperture settings.

Hope this helps. Would love to see your test images.

Philbert

[David]

Hi Philbert

I have had a quick look at my tests from yesterday and I can confirm so far that my 28-105mm f3.5-4.5 Nikkor is producing back-focus results on two S2's tested. I will post more info. as and when I get the time to make a proper accessment.

In the meantime here is the test result from a few days ago.

Lens: 28-105mm f3.5-4.5 Nikkor D.
ISO 100
Sharpness: Hard
Contrast: Normal
Shooting Mode: Manual
Exposure Mode: Manual
Exposure: f4.8 1/125
Studio Flash
Fine Jpeg
4256X2848
Auto Focus

I focused on the 2nd box from the right and the camera has focused on the box on the very left!

In my further tests I have tested four lenses and manual focused the 28-105mm. I will keep you posted as to how I got on.

Cheers

David

[Hugensjr]

Hi all,

Last weekend I talked to a friend of mine about the soft-focus issue with my S2. This friend told me that it could be a backfocus issue. I did not know what backfocus was, but as far as I know now, its the ability of the CCD-chip, to move (a very little bit) forward and backward in order to calibrate the correct distance from the the lens to the CCD. Maybe I'm not explaining this the right way, but read this link: http://www.dpreview.com/forums/read.asp?forum=1020&message=3720157. Here you will find a test which indicates a possible problem with backfocus on the S2 that some of us are having.

In my case, i'm having problems with long distance shots. When the lens is set to eternity, there is no margin left to compensate the incorrect placement of the CCD. When the lense is focussed somewhere around 2-4 meters (on a 28-70 mm) this margin is sufficient to take a sharp picture.

All the things Fuji says about 'the S1 was to hard' refers to me as nonsense!!
When we can prove that there something wrong with some people's S2, we have to team-up. Letting each other know what the responses are from the Fuji Service departements!!

[David]

Hi Everyone

My news is that Fuji UK now have my S2 for "re-calibration of the software!"

I shall wait and see if it has solved my back focus issue!


Cheers

David

[Hugensjr]

In addition:
While reading the Fuji SLR forum on DPreview, I read a post from a dutch guy called Sjoerd. He has had contact with Fuji Service concerning a soft focus issue while using non-Nikkor lenses.
Here, read this:

****
Besides that, Fuji sent me this excerpt from .... (don't know what document exactly) about sharpness issues and DOF on S1 and S2 bodies:

?Focus Level for FinePix S2Pro
1) The depth of field

Although the resolution of S2Pro is much higher than that of S1Pro, the depth of field for S2Pro is shallower than S1Pro, much more conventional film cameras. Therefore the gap of focus point may be recognized clearly.

The smaller aperture (recommended above F 4.0) will be recommended for shooting.

2) Sharpness

The "Standard" level for sharpness and contrast of S2Pro is set a little bit softer and lower than S1Pro for later retouching on PCs.

Therefore S2Pro users are recommended to set "Hard" for sharpness and contrast depending on the subjects or use retouching software to increase sharpness and contrast (Photoshop etc.) on PC.

3) Manual Focus using View Finder

The camera body of S1Pro and S2Pro are Nikon F60 and F80 respectively.

The focus point of the viewfinder is set for conventional film camera and there is difference between the positions of CCD and film surface.

Therefore S1Pro and S2Pro users are recommended to use AF lenses.

****
Rather confusing.....

I still think there can be something wrong with some S2's concerning displaced CCD or something like that....

Patrick

[Tom V]

Sjoerd's message sounds like a load of BS.

The camera does not determine the depth-of-field, lens geometry (and aperture) does. If you have to stop a lens down for a subject that YOU FOCUS ON (manually or with autofocus) to BE IN FOCUS on the film or sensor, the camera's film plane (sensor plane), or autofocus mechanism is simply in the wrong place or out of adjustment.

A 50mm lens at a given aperture has the same depth-of-field whether it is used on a digital camera, 4x5 camera, APS camera, or 35mm camera. For a camera to be said to have more of depth-of-field than another, it is probably a matter of one camera using a different "normal" lens than the other.

Sharpness, as applied post-exposure, in the camera or in Photoshop, is not the same as focus. Applied sharpness can overcome some apparent lack of focus or lack of sharpness, but it will not bring an out-of-focus image into focus. Applied sharpening, either in-camera or in-computer is done by enhancing the contrast between certain pixels (determined by pixel-to-pixel contrast, which is greater at subject edges, color changes, and surface details.).

Focus and sharpness are two different things. You can use a junk lens, focus it, and your subject will be focused but not sharp. You can use a fine lens, miss the focus (focus on the wall behind your subject), and you subject will be out of focus, and the wallpaper can be sharp. NO AMOUNT OF SHARPENING will make your subject in focus.

If you have a subject of 5 cereal boxes, all at different distances, and you and the autofocus focus on the middle distance box, but the resulting image has the farthest box focused, no amount of sharpening or camera setting will fix that. The camera sensor is in the wrong place, or the autofocus mechanism doesn't know where the sensor plane is (out of adjustment), or the cereal boxes are moving too fast for you.

Be certain you understand your camera's dynamic autofocus settings. Sometimes it can focus on the closest detected subject, despite what you think it is focusing on. I don't want to be outsmarted by a chip, so I have my camera set to ordinary autofocus.

If you can manually focus your camera better than it can autofocus itself on normal, static, well-lit subjects, you either have amazing eyeballs or a bad autofocus system. If your $2400 autofocus camera requires manual focusing and stopping down to ƒ4 to get a shot in apparent focus - the camera is messed up.

For a camera manufacturer to make a digital camera and not put the sensor on the camera's natural film plane is insane.

My feeling is that Fuji has made a batch of cameras with the sensor in the wrong place. These cameras should be repaired or replaced by Fuji without question.

[Philbert]

Hello everyone,

Still waiting for my camera to come back, I haven't posted for a few days so I thought that I would wade into the discussion with some WAGs (wild ass guesses) of my own concerning the causes of the focus accuracy problems we are discussing.

When I saw the post Patrick refers to I was confused about the 1st statement:

>"1) The depth of field

Although the resolution of S2Pro is much higher than that of S1Pro, the depth of field for S2Pro is shallower than S1Pro, much more conventional film cameras. Therefore the gap of focus point may be recognized clearly. "<

Since then I have read the excellent DOF thread on this Forum in the lenses section in which John (Stormfield) shows how a smaller image size results in a shallower depth of field. The S1 sensor is larger than the S2 sensor so this first statement makes some sense.

While this point underscores an increased need for accurate focus mechanisms it does not address the issue where the focus is not accurate.

I accept the 2nd point about Sharpness at face value and believe that it has no bearing on an actual focus issue.

The third point is the one that bothers me the most:

>"3) Manual Focus using View Finder

The camera body of S1Pro and S2Pro are Nikon F60 and F80 respectively.

The focus point of the viewfinder is set for conventional film camera and there is difference between the positions of CCD and film surface.

Therefore S1Pro and S2Pro users are recommended to use AF lenses."<

WARNING WARNING WARNING -- WAG starts here ->

I suspect that most of our problems come from this last item. I would not be suprised to learn that the manufacturing process produces an expected range of variance regarding CCD placement. Fuji most likely expected these variations to be compensated for by the autofocus system. This would require a test be conducted to determine the relative offset between the autofocus sensor and the actual CCD position. By knowing what this offset is, the camera could calculate and apply a small focus correction as its last step in the autofocus process. The more correction which is applied, the more out of focus the image would appear in the viewfinder. In the case of cameras which exhibit a focus problem, something may have gone wrong in this calibration process (it was performed incorrectly or not at all) or the offset was larger than could be corrected.

The only part of this pipe dream which I haven't worked out yet is how the autofocus system knows when the intentionally misfocused image at the sensor is no longer accurate (as when operating in the manual focus mode).

I would love to read an authoritative article on just how the focus system on our beloved S2's actually does work. Then I wouldn't have to guess.

Philbert

[David]

Tom

I think that you are spot on in what you say in your last post. Fuji have messed-up in producing a bad batch of S2's and that they know about it, have probably worked out how much it will cost to do a recall and realise it will cost them a fortune so are keeping quite about it and attempting to B.S us all! This happens all the time especially in the motor industry.

David

[Hugensjr]

Hi Tom, Philbert, David and the others,

Tom, Thanks for your clarification on the focus-sharpness issue, and also I doubt the statements from Sjoerd, but: why should he make them up?? It could possibly be information from Fuji....

I now own my S2 for two weeks and did not have too much time for any seriously shooting. So far I shot about 400 images, but mostly in-home with flash. Only a couple of shots were taken outside (the woods) and those shots are shots which I'm most concerned about. All the shots taken with mostly the lens set to 'infinity' were the most out-of-focus. Those shots from those you think 'not to special, good light, and click!'. These simple images must show up as 'good', but as I told earlier in the forum, even on the LCD screen I could see the unsharpness.

My main question on this issue in in fact:

When it's true that the CCD is not placed in the correct position, why is the focussing actually correct in shots from 1 to 5 meters? When there is a discrapence between the autofocus module and the alignment of the CCD chip, why does it not appear on those closer pictures???? Can anybody explain this? My first assumption is that when the lens is focussed to closest or the farrest point (inifity) that there is no 'slack' or margin left to compensate the out of focus point.....but I think that's not completly right.....

This weekend I will run through some tests to convince myself (and you) if there something /nothing wrong with my S2.

Bye,
Patrick

[Philbert]

Hi Patrick,

If you have alignment based focus problems at close distances, they will be masked by the improved depth of field of high f-stop values. Your indoor flash pictures would be higher f-stop shots unless you specifically set the camera to a wide aperture (low f-stop) setting in A or M mode.

I do believe that the Sjoerd message info is from Fuji. I have heard many of the same things in my contacts with Fuji customer service in New Jersey and from others posting on this site and the dpreview site.

Hope this helps.

Philbert

[David]

Hi Tom, Philbert and Hugensjr,

I now have my S2 back from Fuji UK. The service sheet states that "We have adjusted the focus and auto focus restoring the camera back to full working order"

I have run the same tests with the cereal boxes and because I still have the D100 loan camera I was able to do a side by side comparison at 200ASA of course because the D100 doesn't go down to 100ASA! The S2 is now focusing where it should and is no-longer back focusing. The S2 is marginally sharper than the D100!

I did however test the camera with my wife standing in front of some curtains and as before the camera went to Fuji it focused on the curtains. I again used my SB80DX and its focus assist lamp lit. The lens was around the infinity mark. I shall have to run more tests! I think this could be due to the low contast on my wife's face?

I am pleased with Fuji's turn around and service. It took them a week to get the camera sorted and returned to me. WarehouseExpress.Com have been brilliant they lent me the D100 and even sent me a spare battery when I was concerned about running out of power using the single Nikon Lithium battery supplied with the camera.

David

[Robert Karpa]

Hello,
I have some minor focus issues with my S2 Pro and have noticed a rather interesting behavoir. For background information my S2 will set the focus a little closer than it actually should. For example I have done tests shooting the S2 product box and I need to move it just a little closer to the camera to achive the sharpest focus. The offset is around 1 cm for me - very minor but if you are shooting within 3 to 5 feet wide open it could become an issue - othewise the depth of field will take care of it. I have not noticed any problems at longer distances. I can also focus manually with great accuracy as long as I ignore the little green focus indicator light and just set focus where it looks sharpest through the viewfinder.

What I find very odd is that I have done this test with a Nikon 60mm Micro lens. At normal but close camera to subject distances of 6" to 5' the offset is apparent. But when I am in very close to the subject (closer than 6") the camera autofocus is absolutly bang on. I am wondering if the S2 software is adjusting the autofocus offset (if indeed there is any such thing) depending on the camera to subject distance. The S2 camera software "knows" the camera to subject distance - it makes adjustments of the effective aperature to compensate the exposure when in macro mode. For those not aware as you get in very close with this lens you will have to open up to compensate as you would if you where using extension tubes. The S2 does this automatically. Could the S2 software also be compensating the autofocus offset??
Robert Karpa