Zeiss Planar 80mm f2.8 - Blurry Parts

<p>Hey guys!<br>

About half a year ago I purchased a Hasselblad 500c/m with a standard lens, Zeiss Planar 80mm f/2.8. Since then I also got a 50mm lens.<br>

<br />After not shooting for about a month, I shot two rolls this weekend and developed them. What I saw was that the pictures taken with the 80mm lens on the second roll seem to be blurry in the lower quarter (example below) while the 50mm ones aren't. The first roll was already inside the camera since last time I shot but the pictures I took this weekend (80mm) were all fine.<br>

Do you know what could cause this? Could the film have been inserted incorrectly somehow, or might it have been loose? I did everything exactly as usual and had never had this problem before. That would also not explain why the pictures taken with the 50mm are sharp.<br>

Or could the lens be the problem? I'd be surprised if the loss in sharpness happened overnight like it did but would this be a possibility?<br />I have the feeling that focussing is a little more difficult since it happened but I might just be searching for explanations... I had a quick look through the lens and couldn't see anything like mold, dust, etc.</p>

<p>Example:<br>

I took this at either f8 or f11, so the picture should be totally sharp. Other examples were the same, always a linear gradient in the lower quarter or so.<br>

<img src="http://fs5.directupload.net/images/160329/ti74qird.png" alt="" width="867" height="888" /></p>

<p>I hate to be non-helpful, but are you *sure* that image is from the second roll--which you presumably loaded freshly into the back? And were *all* the photos on the second roll blurry like this, or just the first one you shot?</p>

<p>The reason I'm asking is that if a roll is left in the back for some time only partially shot, it can develop a slight "kink" where it goes through a greater than 90-degree reverse bend to reach the film gate (even despite Hasselblad's excellent measures to ensure film flatness), and this could lead to unsharpness in that area on at least one frame, and possibly two. That's why I never leave a roll only partially shot, and when I do load up a roll of film I know may not be shot for a while, I don't actually wind it on to the first frame until I'm ready to shoot it.</p>

<p>So, I've possibly--probably--not shed light on your problem, but I'm hoping that with a bit more information from you someone else can diagnose it more completely.</p>

<p>It was definitely from the second roll and it wasn't the only one. As I said, those I took with the 80mm lens (9 pictures) are blurry in the same area as the one shown above. The 50mm ones are sharp throughout the frame. All of the pictures were captured within two days, most of them during the same afternoon.<br>

Since it only affects the pictures shot with the 80mm I'd say it has to be the lens but I have no idea how it could have changed so much from one roll to the next. I also checked the lens again in better light, apart from some dust on the outside there's nothing wrong with it.</p>

<p>I guess the best would be to shoot another roll quickly and check the results for sharpness...</p>

<p>If it was the lens you'd see the same effect in the reflex finder. A blur that bad would be hard to miss.</p>

<p>My guess is that the film lost flatness somehow. Film can take a "set" if stored for a long time and if the kink in the film is within the frame area then that would explain the partial misfocus seen above.</p>

<p>If you can see the same blurring in the viewfinder, then it's the lens. Dust wouldn't cause that. It would take a badly misplaced or loose element to cause that. Does the lens rattle if shaken? Is there a slight shift of weight as the lens is moved gently in your hand?</p>

<p>Any chance that the 80mm lens took a fall between rolls? It could be a misaligned lens element.</p>

<p>Another possibility is that maybe your 2nd roll was not fed under the retaining lip when loading it. If you don't know what I mean by this, skip to 2:40 in <a href="

youtube video.</a> It would still be hard to explain why the 50mm shots on that roll look fine though. </p>

<p>>It would still be hard to explain why the 50mm shots on that roll look fine though<br>

Maybe blurriness was not as easily discernible due to increased DOF. </p>

<p>Rodeo Joe: The effect was on many of the pictures. I'll check for blurriness through the viewfinder but I need to stop down for good results, so I need to wait until the sun's up. Will keep you updated!</p>

<p>Ray: I thought about the same, that a lens element got misaligned somehow. However, I treated the lens as carefully as I always do, it didn't fall, didn't bump into anything... Do you know how much it would cost to repair a misaligned lens element? I don't think it's the film, it would be too much of a coincidence that all of the 50mm pictures are fine.</p>

<p>I'll go shoot the rest of the roll tonight, with both 50 and 80mm. The sooner I can develop it and have a look, the better. I'll try to shoot subjects that make analysis and comparison a little easier...</p>

<p>Thanks for your help!</p>

<p>I guess I found the solution. First of all, I had a look through the viewfinder once more and realised that when I move my finger in front of the scene, the background gets strangely distorted. Just to make sure I compared with the 50mm and everything's fine there. Plus, I hear a loose part inside the lens when I carefully shake it...<br>

So, Ray, I guess you're right. One of the lens elements seems to have come loose or is at least misaligned as you suggested. I hope it can be easily repaired...</p>

<p>Thanks for your suggestions, I really appreciate the help!</p>

With some of the all metal lenses it could be as simple

as a loose metal retaining ring. With some of the later

lenses a broken plastic part could be the problem and

that is terminal. Good luck.

<p>Actually, a broken plastic part <em>may</em> not be terminal at all, thanks to the wonders of 3D printing.</p>

<p>I've got a 150CF lens which features a rather fragile plastic retaining ring that keeps the focusing collar from slipping backwards. I bought a lens (at a healthy discount) which had a crack in this ring that had been epoxied by the previous owner. I used it happily for a while, but then the epoxy gave way. So I repaired it myself, but then the same thing happened again later.</p>

<p>I checked around to try to find a replacement part, and most repairers said it was unavailable and they'd love to get their hands on some themselves. I had one tell me that he had them--but he wanted nearly $125 for it, which I thought was a bit much for a piece of plastic (that according to a repairer here in the UK, Hasselblad sold--when they still had them--for around $30).</p>

<p>I took the ring to one of the most reputable 3D printers here in London, and they're going to make one for me--for the equivalent of about $75. Still steep, but most of that was for the original technical drawing--the part itself can be printed off for about 12 bucks at any point in the future. I'm going to see if I can't defray the cost to some extent by offering to sell some of the repairers a few of these bits, which will bring my cost down from what I regarded as at least being already reasonable.</p>

<p>So if it is a plastic part, there may be new life for your lens after all--and it may cost far less than you might think.</p>