What does the Lens lettering mean, (+ a SFXn lens question)

I see allot of talk on the forums about A, F, and other letters for lenses. What does it mean? Is it an indication of Automatic and Manual? What do the other letters stand for?

I have an SFXn I purchased in London in 89 on a trip, (I'm a yank, from Texas but we don't put those 2 words together here lol). And am looking to change lenses.

I have rarely used my SFXn, and was considering a digital version, but the D SLR's are too expensive for me, though I payed about 400 pounds for the SFXn at the time. It came with a sigma 28 - 70 mm zoom, and though i like it, it doesn't take phenominal pictures, maybe that's the zoom, or my choice of film, or me. I'm not that knowlegeble about camera's.

Here's my problem. The SFXn isn't real smart in very low light, and I have no problem doing it manualy, but there's nothing to grab hold of to focus with, unless the zoom is all the way out. Also though i have rarely used the camera, I notice the lens is making a noice, maybe assosiated with grit. For whatever reason I want a new lens.

My question is: What's a good all around lens for the SFXn. Or if it's not known for great pictures, I could sell the camera and get a newer film SLR? I understand the SFXn was was one of Pentax's first autofocus camera's?

David
Galveston county Texas US.

The SFXn was possibly the second in the series of AF bodies, and the autofocus is probably a little slow by modern standards. However, there is no reason at all why you shouldn't take great pictures with it, and if you need a new lens then any Pentax AF lens will be fully functional.

You can also use any manual focus Pentax lenses, with limitations depending on the lens.

In summary, the letters mean:

Manual focus:
S lenses are screw thread, labelled Takumar. Super takumar, SMC Takumar
K lenses are the first bayonet lenses, labelled SMC Pentax
M lenses are the compact range labelled SMC Pentax-M
A lenses add the ability for the camera to control the aperture via electronic contacts and are SMC Pentax-A
F, FA lenses are autofocus as well.
FA-J have no aperture rings and are thus set permanently on "A"
DA lenses cover a smaller image circle and are for digital SLRs.

The nice thing is you can still use all of these even on the latest digital bodies! Fantastic!

If you are looking for something really special then a Tokina 28-70mm AF f2.6-2.8 is a great idea or the more expencive 28-80mm AF f2.8 also the Sigma 28-70mm EX 2.8 lens is great. But these lenses are quite expencive. If you would be willing to fork out the money for one of these then they will increase picture quality to no end over a standard Sigma lens. Pentax own lenses are also a good bet as they are very available on Ebay and fairly cheap. One in particular stands out for a cheap but great sharp lens. The pentax 28-70mm F4 AL. This lens may not be as fast as the others i have mentioned but it is sharp and well respected in the comunity. It is also very cheap.

I hope you know what the F2.8's and f4's stand for, but if not then here is a quick rundown. The lower the number the wider the lens can open and therefore increases the light going in. This is something to note as it will also increase the amount of light getting to the autofocus sensor and therefore also increase the potential for your camera to get a good sharp focus.
Weight is also another issue to be considered here as the more expensive f2.8 lenses have a lot more glass in them and therefore weigh considerably more.
Anyway, thats all i'm going to say on the subject for now.

Hi,
If you are looking for a new lens and are on a budget, I would recommend the FA 28-70/4 AL. This is a cracking lens and also one of the cheapest on the second hand market. In the UK, you can pick up a good one for less than £50 from a dealer.

Steelski beat me to it!!

Kim

Hey thanks guys for the sugjestions, and explaining the lettering system guys. I got my lens tonight, but it's nothing fancy. I was at Ritz, and they didn't have any Pentax lenses for my camera. The only lenses he had for my camera were 2 sigma's. The first one didn't work right. The one I got is the Sigma 28 - 80 mm zoom with the macro button. It was not very expensive and it has it's own manual grip for the focus, which was really what i needed. The macro button is nice.
With a possible D SLR in the future, (if the prices drop), I didn't want to spend too much, and I was freezin my tail off tonight lol. Then i crossed the hyway and bought my epson photo scanner.

And yea the camera guy was a Nikon fan of course, figures, but he was nice. Personally I think Nikon and Nike have something in common, it's all about a name, but I'm too much of an ameteur to know that for sure about cameras.

Thanks for all the great help guys. This is a great forum.

Now I need to do some searching on the net to learn some basic f stop info.

Ok

I Want to talk about this and maybee start another thread entirely. Is it possible that even though Nikon have a higher currant profile than many others, that people such as yourself would be avoiding them because of the high profile name. Could it be that some people dont want to be assosiated with Nikon or Canon because they are high profile like the Nike's and Adidas's of the camera world.

Another possibility that i would like to explore is that people dont want to admit that a particular lens that they own or a camera is superseeded by something someone else has created. I own only PK gear and wouldent trade it for the world (thats a white lie), but even though i know there are other manufacturers out there i dont like to see anyone in particular fail, and would trust to take pictures with them. I do feel that the only real othe camera i would like to explore is Minolta because it is not doing as great as Nikon or Canon. Maybee i just like to back the slightly litteler guy.

On the Sigma 28 - 80 mm zoom AF I bought, I can only turn the focus ring half way. To use the rest of the range I have to use the macro button. Is this normal? The macro numbers are in gold, yet the white numbers beneath, representing the normal focus range, (I assume), goes almost as far as the macro letters above. How come I only have have the focal range whithout macro? If I flip it on macro, I'm only using the macro top numbers right? Or does it do double duty?

Confused.

That's suppose to say; have "half", the focal range, not have have, sorry.

Took pictures of our first white christmas here in the Texas gulf area near Galveston. Only ever had snow on the ground 3 times before this in my life. We'eve never had a white christmas. So we were frieking.

I think that is normal for some lenses, the minimum focussing distance varies depending on the focal length that you have selected.
If only half of the focussing range is available at any given focal length, then that sounds a bit dramatic and I suspect that it may not be functioning correctly.
Can you confirm the distances that are available with and without the use of the macro button? - they should range from infinity (the sideways figure 8 symbol) down to a few metres. The macro button should then allow focussing at closer distances and the markings for macro settings are usually in a different colour.
Often, it is difficult to focus within the macro range by using the focussing ring and the normal technique is to move the camera and/or the subject until correct focus is achieved.
Some lenses are designed so that the macro function is only available at a certain focal length (the telephoto end) and operating the button will alter both the focussing and zoom rings.

Sorry I can't be more precise but I'm not that familiar with Sigma lenses, although some of them are very good indeed and they generally represent good value for money.

Kimbo,
when not using the macro, I can only turn the focusing ring from infinity to just past 0.5 The lettering continues around to 0.25 over an inch away, but I can't turn to it. Those are in white. The macro letters above (on the left side only,) are in gold. To use the macro i have to put the telephoto on 80, (full zoom), and the focasing ring has to be 0.5 +.

Once in macro i have the full motion, even though the gold macro lettering is only on the left.

The purpose of macro is to provide close focussing. That is why you need to be in macro mode to be able to focus closer than 0.5 (which is pretty close anyway for a non-macro lens).

George

Yea I know what a macro is, but it isn't confined to just the macro lettering. With the macro button on I can rotate the focus ring freely from the closest macro seting back to infinity, but when shooting normally without macro I can only turn it half way. Seems to me it'd make sence to be confined to the macro numbers alone when it's switched on, and have the free range on normal shooting. Unless its designed to be on macro to get the other half of my normal focal range (which seems bizzare to me), i don't get it.

Thanks.

Hey if i wanted a strait 50 mm lens, (I think it's called a prime), that would work with my SFXn's auto focus and auto aperature settings what should I be looking at? Just AF's? I see them on ebay and was thinking about getting one as a second lens. Looking for a shorter, faster lense that I can use well in low light. Would like it to be a Pentax, but would settle for another sigma, if i have to buy it new, (haven't had much choice in pentax here). The only 50 mm primes i see listed new from sigma are also macros. Don't nkow if that matters, but I have a macro on my 28 - 80 though i think the 50 mm macro is closer than 1.2

I'wouldn't mind an optional manual focus ring, but definately want this one to be automatic too. The one I saw on ebay was SMC, dunno what letters folowed it, i'll have to look again. Thanks for all the lens listings earlier johnriley, and the info on the f2.8 lenses steelski, (hey my name ends in sky, are you polish too (: .

David.

SMC (Super-Multi-Coated) Pentax lenses with suffixes such as -F and -FA will be autofocus and suitable for your needs. There are f1.7 and f1.4 versions and I would suggest they will be better than the Sigma lenses.

Macro lenses are also available in 50mm, but are usually f2.8 or even f4 but very highly corrected for closer work and giving magnification down to 1:2 (a 1cm long item will be 0.5cm on the film) or even 1:1 (that same 1cm item would be 1cm long on the film). I still believe that the Pentax ones will be better.

For a lens used mainly for Macro work I am not convinced that you need autofocus, in fact it is a nuiscance. So you could think about a manual focus macro lens which would be labelled SMC Pentax, SMC Pentax-M or if you want auto aperture operation, SMC Pentax-A

hey thanks again John.

Since my minni zoom sigma allready has a 1.2 macro, (and I found out that was the sigmas), i'm gona just get a dedicated 50 mm. Right now the smallest things I'm shooting are leaves & flowers up close anyway. I been doin some net searching tonight with the help of the info I got here, and I've decided I want a Pentax. If I have to order it over the net I will. I also want a better aperature. My present lens is a min 3.5, and it's been so grey and overcast here, (and I'm such a nite owl), i'd have to use a tripod. I see some of the pentax prime 50's come in 2 and 1.5 aperatures.
I been thinking about the smc P-FA 50mm F1.4 and smc P-A 50mm F2.0 & F1.2 that are listed on the Pentax website. Only thing is the first one is FA, and no focus ring, and the other two are manual focus only. I guess the P stands for pentax.
Any of those 3 are probabaly going to cost me triple what my sigma did, but i want one. Whatcha think?

David