manual lenses w/Pentax DSLR

[ken1953]

Hi all, I've been playing with my new pentax today and broke out my old lenses. One is an 80-200 1:4.5 Focal MC Auto Zoom and the other is an SMC Pentax-M 1:2 50mm lens. I have figured out how to put these on my camera and am starting to figure out a little about them. But would like some advise on how to set them in full manual mode, and when is best to use them. I had problems using them, especially trying to figure out my iso settings with the f stops and apeture settings on the lenses. Most of the shots I took today were either too dark or too light. Any hints would be greatly appreciated. Here are a few pics of the lenses. These are all circa early to mid 80's. I have one of the zoom and 2 of the 50mm's.
First set of pics are the 50mm
Next post will be the zoom.
Ken

[ken1953]

The zoom lens...thanx in advance for any tips, hints and suggestions.
Ken

[another view]

I used to have one of those 50 f2 lenses with my K1000. If I read your question right - there isn't any manual mode on these lenses. They're always manual . As long as you have in-camera metering (like what you lose on some Nikons with manual focus lenses), then you should be fine. The only thing is that some DSLR viewfinders are fairly small which may make focusing a little more difficult. Well, another - most focusing screens for autofocus cameras don't have focusing aids like a split image that you'd see in an older camera. Some of the Nikons have an LED that lights up when you're in focus, but I don't know that camera.

When I'm out shooting, I usually decide what ISO speed I want to use and leave it. I might have to change if I'm not getting the results I want, but usually I don't change it much. Try leaving it on 100 if you're outside and not worrying about it. Then you've got one less setting to deal with. From there, set the aperture and shutter speed. Then shoot!

[ken1953]

Hi AV...I believe you are right...these are both fully manual with the DSLR. Also, I'm kinda stuck at ISO 200 with the Pentax...it's range is 200-3600. The Pentax tho' will beep when I am in focus, so even in full manual it does offer a little focusing assistance. On the 50mm...I put it at the highest fstop and played with the shutter speed to try to get things darker. I know I will have to play a lot with these lenses to eventually learn them, but I appreciate all the advise everyone gives me. It really helps a lot and of course makes my experimentation a whole heckuva lot easier. hehe...
The 50mm lense is in super condition and the few shots that came out were super. Even better than my kit lens, so I'm really gonna work hard to learn the 50mm...I think it should probably make an excellent macro lens or am I wrong.
Anyway..again..thanx for the advise.
Ken

[another view]

[FONT=Verdana][COLOR=#000000]On the 50mm...I put it at the highest fstop and played with the shutter speed to try to get things darker.

If you're in any kind of automatic mode (aperture priority or program - or whatever Pentax calls these modes) then only adjusting the aperture isn't going to darken a shot. What will happen is that the shutter speed will slow down one stop for every stop that you close the lens down - to compensate for what you're doing with the aperture. You'll have to do this with exposure compensation (-1, -2, etc) or shoot in manual mode.

The 50 can make a good macro lens, but it won't focus close enough to make it work as-is. You'll need an extension tube and/or a close up diopter (a.k.a. close up filter) to get it to focus close enough that it will work as a macro lens.

[Kim026]

Hi AV...oh...ok...shows why I asked the question...so what would the 50mm be considered, and what would it's main uses be for??? I guess because it was a small lense I automatically assumed it was a "macro" lense...hehehe...
Ken

[Kim026]

Geez...I'm gonna have to get a new monitor or start editing all my stuff on this computer...I didn't realize how bad the adjustments were that I made on the photos...
hehe
Ken

[another view]

Ken, a 50mm lens is considered a "normal" lens because the perspective of it is pretty close to how your eyes see. This perspective has to do with the focal length and nothing to do with the crop factor which makes the angle of view of this lens closer to that of a 75 or 80mm lens on a 35mm camera. If it were a macro lens (usually between about 50 and 200mm), it would be able to focus an image at about life size. With 35mm, this meant that you could fill the viewfinder with a US Quarter ($ 0.25) and it would be in focus. Of course with the digital crop factor I guess it would be more like a nickel that would do that...

So - a 60mm macro lens can be used as a normal lens in most cases, but a normal lens can't be used as a macro lens without the extension tube or diopter I mentioned. Try it out - see how close you can focus something. There are some other differences between macro lenses and non-macro lenses of the same focal lengths, but this is the important one. Ever try your Coolpix in macro mode? Downright scary how close it can get!

[ken1953]

hehe...yeah AV...I have tried the CP...but I have had better luck in manual mode with my macros...for some reason when I set it on macro modes my focusing is off and I can't seem to figure out why...I need to learn more about DOF for that one.
I'm still a little confused about the "normal" lenses, but I do understand the differences as you discussed. And I have been playing with it this morning. I have to back off about 1-2 feet before I get a good focus. But, after that, it's very sharp and crisp. My CP taught me a lot, but in the past 48 hours, I have been challenged even more and am learning like never before.
Thanks for all the help.
Ken

[another view]

I need to learn more about DOF for that one...My CP taught me a lot, but in the past 48 hours, I have been challenged even more and am learning like never before.

DOF is very, very shallow in macro situations. To get more DOF, you can stop down to f11 or maybe even lower (higher f-stop number) and this will usually give you a long shutter speed. You'll need to use a tripod and the self timer will help too so you have a sharp image. It gets tricky, but with close focusing like that you will have a very shallow DOF - just how optics work.

Challenging is good - that's how you learn!