Petri 7s with oil problem

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vidgamer

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It has the typical oil on the blades, but it does function, so I'm tempted to just live with it. But there appears to be a spot of "something" that either is a tiny bit of oil or some sort of visual artifact.

I was afraid that having the spot in the center would be enough to affect images, so I thought I'd go ahead and try the q-tip aperture cleaning and try to clean the spot at the same time. But I'm not able to get that far.

I tried removing the front part of the lens, but I'm stuck at the 2nd group. Do I need a lens wrench?

Perhaps I will just put it back together and try a roll. I just hate that the spot is right in the middle of the frame....

Otherwise, it looks like a really nice camera! 🙂
 
But does it have a small drop of oil in the middle of the rear element? It is odd, and I'm convinced that it will have some affect on the photos. Although, at wider apertures, it's relatively small. At f16, it's a significant portion of the lens!

I could live with the oil on the aperture.

I guess I could burn a roll, and try different apertures to see the effect, if any.

I wonder if I was one set-screw away from getting inside? 🙂

As for the camera, I like the look of it. Nice timeless design, IMHO.
 
Not yet! I'm curious too. I just haven't come up with a lot to take photos of, and all I have are 24exp rolls... And then, if I want to share my results, I have an additional problem that I can't find the negative holder for my scanner (and I'm not sure if I need that, in order to have accurate spacing). Much different than the instant gratification from digital. ;-)

It won't surprise me if it ends up being very difficult to tell that there is anything on the lens. What seems to happen, when I look at some web pages that demonstrate junk on the front of a lens, is that you end up with a "loss of contrast" and it's hard to quantify that. (Unlike digital cameras where specks on the sensor show up nicely.) I mean, if I look at the resulting photos, how do I tell that it has slightly less contrast than the camera may have had when new? Well, it will be interesting to see what comes out.

I saw another thread about the shutter being quiet. I guess it's not as loud as an SLR -- certainly not as loud as my noisy DSLR -- but it's not as quiet as I expected. But when you wind it, it has a really loud CLUNK at the end of the travel! (This was also mentioned in that other thread.) Weird, but strangely satisfying. ;-)

The needle metering takes a bit of getting used to, but it isn't too hard.

The best thing of all is not having to worry about the camera too much -- it's not like I have a lot of money invested in it, and if someone did manage to steal it, they'd be sorely disappointed in how much money they'd get for it.
 
A drop of oil anywhere on any lens element will have an effect on your photos. This in spite of the fact that you can glue peas to your front element and not notice it in the photos. The reason is that the peas are opaque but the oil is not. Peas just block some of the light. Oil changes the optical characteristics of the lens (as if your front lens element had bumps and ripples in the glass).
 
That's what it seemed like when I looked through the rear of the lens, as if a spot of oil was near the center and inverted the view (on that dot). The inversion of light made it look like a tiny lens tacked onto the rear element. I figured it must either be a spot of oil, or else some sort of visual artifact that I just don't recognize. (Is it possible that it is supposed to look like that?) Although, the spot is very small, so it still might not have a huge effect.

Well, if it's bound to have an effect, that's all the more reason to try to dig in there to clean it. However, I need some advice if I tackle that project again. (I need to know if there is some sort of set-screw I need to loosen or if the lens is really screwed in there that tightly. I think I was pretty close to getting it open.)
 
Well, I managed to mess up the first roll -- the film jumped off the track at a fairly early point. (I'm sure that was my fault loading.) Meanwhile, I had problems getting used to the camera. For one thing, it's easy to bump the ISO lever to a very incorrect setting! And with a couple of photos I tried to use a slower shutter, but couldn't hand-hold it steady enough.... So, due to various problems, I didn't end up with good results with this first roll.

Ok, anyway, I don't see any obvious "blobs" or problems that I can attribute to the previously-mentioned flaw, although there might be a loss of contrast that I wouldn't be able to pin down.

Here's a link to the first photo from the camera:
http://www.flickr.com/photos/avidgamefan/3850146890/sizes/l/

It appears to me that the lens is sharp, and the bokeh is nice. It just doesn't have the "pop" that I expect....
 
vidgamer said:
Well, I managed to mess up the first roll -- the film jumped off the track at a fairly early point. (I'm sure that was my fault loading.) Meanwhile, I had problems getting used to the camera. For one thing, it's easy to bump the ISO lever to a very incorrect setting! And with a couple of photos I tried to use a slower shutter, but couldn't hand-hold it steady enough.... So, due to various problems, I didn't end up with good results with this first roll.

Ok, anyway, I don't see any obvious "blobs" or problems that I can attribute to the previously-mentioned flaw, although there might be a loss of contrast that I wouldn't be able to pin down.

Here's a link to the first photo from the camera:
http://www.flickr.com/photos/avidgamefan/3850146890/sizes/l/

It appears to me that the lens is sharp, and the bokeh is nice. It just doesn't have the "pop" that I expect....
Click to expand...

Looks okay to me too. maybe it is just a reflection of the lens under it (happens occasionally with some Tessar-type lenses).
 
We could settle this right now if someone else with a Petri 7s could set it to "B" and look through the lens! 😀

Would you expect such a reflection to appear as an inverted image or something similar?

I haven't seen anything like it on my other lenses, not that that means anything. 🙂 I tried Googling, but couldn't find any mention of such an artifact (although, I do not know what terminology to use!). I did find an article on how to tell if a lens was a Tessar or a cheaper one. This one seems to have enough reflections (from a light bulb in the room) to be a more complex lens, so I guess it could be a Tessar. Being close to the center made me a bit suspicious at the start that it could be some visual artifact of the lens design, but it is not something I'm familiar with.

I tried to photograph the image of the dot with my slr, and it couldn't do it. It wasn't there. (Now, other effects were present as I moved things around, but there is a point at which I can clearly see the spot, but the SLR could not! Highly suspicious!)

I think I have to assume at this point that it's a weird lens artifact and try again....

Meanwhile, the oil on the blades does not seem to cause an issue. It felt a bit "gritty" at first but works (and moves pretty good now). There seems to be some oil on the shutter, but I don't think that's sticking at all. No, it's more of a problem for me to quit bumping the ASA setting (which is really easy to do and offers no resistance unlike many other cameras). I'll try to fix the user-induced errors and see how it goes.... But it would make me feel better if someone else could confirm the weird spot.

Thanks for the comments....
 
Last edited:
vidgamer said:
We could settle this right now if someone else with a Petri 7s could set it to "B" and look through the lens! 😀

Would you expect such a reflection to appear as an inverted image or something similar?

I haven't seen anything like it on my other lenses, not that that means anything. 🙂 I tried Googling, but couldn't find any mention of such an artifact (although, I do not know what terminology to use!). I did find an article on how to tell if a lens was a Tessar or a cheaper one. This one seems to have enough reflections (from a light bulb in the room) to be a more complex lens, so I guess it could be a Tessar. Being close to the center made me a bit suspicious at the start that it could be some visual artifact of the lens design, but it is not something I'm familiar with.

I tried to photograph the image of the dot with my slr, and it couldn't do it. It wasn't there. (Now, other effects were present as I moved things around, but there is a point at which I can clearly see the spot, but the SLR could not! Highly suspicious!)

I think I have to assume at this point that it's a weird lens artifact and try again....

Meanwhile, the oil on the blades does not seem to cause an issue. It felt a bit "gritty" at first but works (and moves pretty good now). There seems to be some oil on the shutter, but I don't think that's sticking at all. No, it's more of a problem for me to quit bumping the ASA setting (which is really easy to do and offers no resistance unlike many other cameras). I'll try to fix the user-induced errors and see how it goes.... But it would make me feel better if someone else could confirm the weird spot.

Thanks for the comments....
Click to expand...

I just spent about a week trying to clean a hazy spot off of a Zeiss Jena lens's second element that it turned out wasn't really there. I'd take it apart, clean it, reassemble it and that damned spot would show up again. I'd take it apart, clean it again, this time with anitfungal mix, and reassemble it, and as soon as I got the front element into place it would show up again. And so on. SOAKED the element in the antifungal mix, cleaned it and reassembled it. Was about to write it off as etched glass due to lens fungus but I took the thing into a different room and the spot disappeared. Well, the spot would show up on the lens in there and in one other room. If I look at other Zeiss Jena lenses in there, it looks like there are spots in them too. The spots don't show up in other types of lenses and you can't see them in other rooms. I figure it might have something to do with the lighting, the textured ceiling in that room, and the dome shape of the second element. It occurred to me that you might be seeing the same thing.
 
What a discussion here! This is not easy camera, mentally, I mean. First I were about to leave it as is because of feel and build and RF patch, though lens seems nice - at least, to me.
I remember some head scratching to separate elements of front group. They separated applying tension to different place than it looked naturally. Though nothing criminal, finally.
 
OK, well, I guess I'm glad it's not just me!

I think one time I did think I saw a spot or scratch in one of my lenses that turned out to be something in the room oddly reflected in the lens... but this seems different, like as if a small lens (say, 1mm) such as would be caused by a drop of liquid, since the image inverts so cleanly. But maybe it being so clean is more evidence that it's supposed to be that way! Surely a drop of oil would sag or be oblong or....??? The funniest thing is seeing it and then putting my DSLR with a "macro" (well, 1:2 macro) lens up there and .... it's not there. Creepy.

I'll try again... I WANT to like the camera. The bokeh is something special, I think, with this lens. And it seems plenty sharp (although my scanner doesn't resolve that high so I guess I don't really know for sure).
 
OK, I'm going to stop looking at the weird dot in the lens, load up more film and try to enjoy the camera. 😱

Thanks for all of the comments. I'll have to post again in one of the other forums once I get some use/practice.

Great bang-for-the-buck...... Tempted to get a 2nd just to check the lens. :bang:
 
vidgamer said:
OK, well, I guess I'm glad it's not just me!

I think one time I did think I saw a spot or scratch in one of my lenses that turned out to be something in the room oddly reflected in the lens... but this seems different, like as if a small lens (say, 1mm) such as would be caused by a drop of liquid, since the image inverts so cleanly. But maybe it being so clean is more evidence that it's supposed to be that way! Surely a drop of oil would sag or be oblong or....??? The funniest thing is seeing it and then putting my DSLR with a "macro" (well, 1:2 macro) lens up there and .... it's not there. Creepy.

I'll try again... I WANT to like the camera. The bokeh is something special, I think, with this lens. And it seems plenty sharp (although my scanner doesn't resolve that high so I guess I don't really know for sure).
Click to expand...

One thing for sure about oil -- it spreads. If you are seeing a clearly defined dot in there, it isn't oil.
 
Yeah, I think it's pretty even, and I've had the camera sitting upright (so it should have sagged if it were oil). I guess it's just an odd artifact.

There's some dust in the lens too... I don't care, I'm putting film in it! 🙂

I don't even mind the oil on the blades, as long as the shutter seems to be working OK.
 
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