[pencilnink]

From it's reputation and seeing picture samples on this forum, I bought a Mc Jupiter-9 and finally received it yesterday. According to the serial # it was made in 1991.
I'm not sure if it's the lens or me (although it's likely me), but I have a hard time nailing the focus on this thing.
Is it normal for this lens to be super blurry at infinity focus? (I'm using the oem pentax m42 adapter btw.) It's to the point where you can't see anything close or far. I know it is a portrait lens after all, so I wasn't sure if this is how it is or if I got a bad copy.

ISO 1600, 85mm, F2.8 1/5sec
No PP just resized.

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Last edited by pencilnink; 02-04-2015 at 08:24 PM.

[JohnBee]

Couple of things.

1. Shutter speed might be a factor
2. have you tried live view for focus?

Also what camera did you use with this?

[Eruditass]

1/5 on 85mm crop? I hope you were using a tripod...

you should be using around 1/125, depending on how good you are at holding it still and how good SR is with your shake profile.

[icywarm]

and mine is soft until about f4 - f5.6

but here.. .higher iso 1600, slow shutter, wide open... means soft image...

[pencilnink]

Oops sorry, forgot to mention I was using a Pentax K-x. No tripod, I got too excited and forgot to pack it. I haven't tried focusing with Live View yet. (rarely use live view as it is.)

Would a katz eye make a world of difference focuing with this lens?

[JohnBee]

Oops sorry, forgot to mention I was using a Pentax K-x. No tripod, I got too excited and forgot to pack it. I haven't tried focusing with Live View yet. (rarely use live view as it is.)

Would a katz eye make a world of difference focuing with this lens?

Well I'd try and figure out if your looking at a focusing issue to begin with.
One way to isolate this is to use LV and focus in using magnification. At which point you can determine if a splitscreen would help with nailing focus.


The main issue being that many Jupiter-9 lenses can be poor performers. I tried 3 before I found one. Though none of them looked as bad as the image you've posted. However, I think your slow shutter may be mostly to blame in this case.

[icywarm]

I am hoping so... I am trying to find one... the website says katseye is not shipping until further notice (family thing)... when I use it on my k1000 it is great...

[interested_observer]

Auto focusing cameras are wonderful. The downside to AF is that whatever manual focusing skills we have acquired over time, tend to disappear instantly. This coupled with the viewfinders on today's cameras - which are not optimized for manual focusing, results in what you are seeing. I still have this Spotmatic II from 1970 and its viewfinder is wonderful. Switching to my K20, is difficult for me to manual focus, I have found. A katzeye would certainly help. This is something that I have not gone to yet, as I tend to do landscapes, and use hyperfocal focusing more towards the infinity end, so it becomes less important.

For what you are trying to do, I think the results are pretty good. As everyone else has indicated, a tripod, 2 second mirror up, external shutter release, live view to focus, etc. will certainly help.

Also, 85mm at say 3 feet, @ f2.8 only gives you a dof of 1/2 an inch.

• Online Depth of Field Calculator

That is pretty thin for the object you are shooting, so by design - most of the image will be out of focus anyway, and you are at ISO 1600. So, either a lot more light, or some mechanical stabilization is in order.

Edit - Also for best resolution I would tend to guess that f4 to f8 will provide the best for this lens. Someone probably has done a review on this that provides a resolution histogram by f stop showing center, edge and corner. The more you stop down to gain resolution, the more light you are going to need (or the longer the shutter duration will be required). Also, to reduce noise, and to help with resolution a lower ISO will certainly help (ISO 200) but that will require even more light or slower shutter - which again pushes you to mechanical support....

[pencilnink]

This is actually my first dslr . I've been using nothing, but manual focus lenses. So theres quite a bit learning curve here on my end. Maybe i'm just spoiled by how easy it is to nail the focus on my SMC tak 50/1.4.
I tried the suggestions with tripod, increasing shutter speed, live view, and it does help.
Maybe I'm just trying to find an excuse to buy a katzeye
And thanks for the help everyone !

[Pentaxor]

at such slow shutter speed, I doubt that you could nail focus even with a Katz-Eye. not to mention it's a manual focus telephoto lens hand-held at fast opening shot at infinite under poor lighting.

[ultraviolet]

so I wasn't sure if this is how it is or if I got a bad copy

When I got mine few weeks back, I did take some pics under different light. Here is one attached. Mine is NON MC, but fellow jupiterians suggested a tele hood (i used tak135 hood) and found absolutely helpful. see this threads 1. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/141188-jupiter...ml#post1474390 2. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/136524-jupiter...ml#post1424480. I think your lens is ok, you might get better result just following those and above advices.

EXIF Summary: 1/4s f/0.0 ISO800 85mm (35mm eq:127mm), hand held

[aurele]

i have a Jupiter 9 and a Kx, and yes it's soft when focusing at infinity at full aperture.

You have to close to f5.6, f8 or f11 to get something sharp. For close portrait F2 is not so bad.

But all in all this lense miss a lot a SMC

[pencilnink]

Btw, is it normal for this lens to be blurry with infinity focus at all apertures? Also, what can I do to fix this? While half pressing the shutter when focusing, the focus assist indicator beeps when everything is still blurry.

[ultraviolet]

Near infinity
EXIF Summary: 1/400s f/0.0 ISO200 85mm (35mm eq:127mm)

[pencilnink]

Ya, mine is nothing like at or near infinity. It starts to become clearer between 6 to 10 meters and anything higher is a blur for distant objects.