Using Lenses for a 1960's Pentax Spotmatic Asahi SP with a Pentax K-r?

[Luke D.]

I know Pentax is well-known for making all of its models compatible with its new camera bodies, and image stabilization is not a problem thanks to the sensor-shift built into their bodies. However, because the lenses I have available are so particularly old, does one need an adapter to attach the lenses to a K-r? Also, could the image quality be degraded somewhat if they were attached to such a modern camera? Would they be difficult to use, focus, or adjust? Would the view or range be cropped significantly if they were used? Would the LCD screen still work properly, would video mode be impaired in any way? I am planning on using my first DSLR while hiking for outdoors and nature images, and am currently deciding between a Nikon d3100 and a Pentax K-r. The lens issue is currently delaying my decision, because I have a basic, walk-around lens, a telephoto zoom lens, and a wide-angle lens available from my parents' old film Pentax. If these could be used, this would reduce the setup price significantly for the K-r. Should I bother trying to adapt old lenses, or just start fresh, and make my decision based on more important factors?

Also, in general: Pentax K-r vs. Nikon D3100? What do you think? I'm aware of many of the differences, but I'm curious what users of this forum think.

 

[Derrel]

Unless one is a real photography "enthusiast", using adapted lenses on a modern d-slr is rather a hassle. I have adapters, lots of them, for Pentax thread mount lenses to Canon d-slr bodies, and also a collection of Nikon F-mount lens to Canon d-slr bodies. Even with a dozen adapters in each mount type, one for each lens in normal rotation to alleviate the need to swap adapters, I have found that using the older Super-Takumar lenses more of an exercise in "process" than a one hundred percent practical, easy, carefree shooting experience. In other words, modern, autofocusing lenses, with automatic stopping down of the lens to shooting aperture, are much easier and more fun to use. Focusing is more accurate with autofocus than by eye, in most cases, especially with shorter focal length lenses. What is called automatic diaphragm control, is what one loses when using adapted lenses on modern bodies. Yes, you've got three old lenses that **could be** adapted to a more-modern Pentax body by way of an adapter. BUT, the camera itself has a viewfinder system that is really NOT optimized for manual focusing. Honestly, I would advise against going with the old lenses as primary working lenses. Sure, they CAN be adapted, and in bright-weather conditions, or in very slow-working conditions, the lack of automatic diaphragm control might not be that big of a problem or hassle to overcome. Whatever camera you get, I would equip it with modern, autofocus lenses.

 

[Dao]

Derrel,

That is what happened to me. Around late 2008, I thought of buying older lens with adapter for me Canon DSLR. After I did some research, I gave up that idea. It's just not worth it.
In the beginning, I was looking for a macro lens. Manual focus, not a problem since I will be using manual focus anyway with my macro shots (at that time, that is what I read from other macro shooters). But later on, I found that I will have to shoot at f/8 to f/16 and it will be tough to do with my current setup since it will be too dark to focus via the viewfinder (even with focus confirm adapter). So I end up just bought the older Canon non-USM 100mm macro EF lens from ebay.

Can it be done, sure. Is it worth it? Not for me.

 

[usayit]

I adapt and enjoy a whole collection of kmount and takumar screwmounts on a pentax dslr as well as two micro 4/3 bodies. Its fun. There are a few here that do so.


Would I recommend to a person who isnt particularly interested in vintage lenses, no. Even less so as a lower cost alternative.


You will need an adapter
You will need to manually stop down and figure out exposure
You will need to focus manually on a crappy penta mirror squinty viewfinder of most dslrs
There is no communication between lens and camera rsulting in limit automation
You will need to know lenses to know which ones will satisfy you... hazy, single coatings, fungus, focus action ... etc


At the very LEAST, stick to manual Pentax-A kmount lenses. You wont need an adapter, auto stop down is operational, excellent SMC coatings, and you can stick the aperture to A and use Aperture priority.
With that said.... some old lenses are excellent jewels. Oh but only on the pentax dslr

 

[Luke D.]

Thanks for the info.

It sounds like it would be interesting to get a Pentax and experiment with the old lenses I already have, especially if they don't need an adapter (which I don't believe they will, since they are fitted for a Pentax mount, and their mount has always been the same), but it wouldn't be a decision-making factor. I'd want the new lenses.

Anyways, the bigger question is still looming over my head: Pentax K-r or Nikon D3100? Furthermore, if I went up a level, Pentax K-7 or Nikon D5100??? My biggest fear doing that is that I might not have enough money afterwards for some great lenses. And then, this really irritates me: Is the image quality on the K-7 really worse than on the D3100, D5100, and even the intro model of its own brand, the K-r? Awesome, weather-proof body and cool design aside, this is true according to Snapsort... And if I got the D3100, would I have to upgrade to a more advanced camera body if I got more into photography? It seems much more specifically a beginner, "don't-worry-it's-easy-as-a-point-and-shoot" type camera. And then the K-r; it isn't weather-sealed or rugged (but maybe more-so than the D3100?), and the way it looks doesn't really appeal to me -- plus, the K-r's video features are not as good. And then, what about the D5100? Much more money, but the image quality, according to my research, blows away that of all the other models I am considering. I feel like the K-r is the smartest choice, the D3100 the safest choice, the K-7 the coolest choice, and the D5100 the most extravagant choice. Would anyone advise anything in particular?

 

[usayit]

It sounds like it would be interesting to get a Pentax and experiment with the old lenses I already have, especially if they don't need an adapter (which I don't believe they will, since they are fitted for a Pentax mount, and their mount has always been the same), but it wouldn't be a decision-making factor. I'd want the new lenses.

Spotmatics are M42 screwmount not the later Kmount. You'll need an adapter.

Sorry.. I can't comment on a comparison between the Nikon and Pentax DSLRs. I will say that it is far easier to find modern Nikon AF lenses in stock than Pentax.