SMC Pentax-A 70-210mm F4

Cloudy Wizzard · 11-21-2007, 07:47 AM

As I just told Tom here I recently (monday evening) bought a Pentax zoomlens from a seller on Ebay (local Belgian).

since this is my first lens (not counting the 18-55 kit lens) I have some questions and I hope some here are able to answer them for me (but I'm quite sure they will).

The seller calls it a "SMC PENTAX- ZOOM A 1:4 70-210mm , 32 tot 4" in as good as new condition. So I've been looking at the lens review section here on the forums and I'm happy to see that most (of not all) reviewers would recomend this lens so I guess it's a fairly good one.

now here are the questions I have about it :

1. what do the reviewers mean with "zoom creep" or plain "creep" ? is that something to worry about ?

2. I assume this lens has the standard K Bayonet mount (will fit on my K100D Super without trouble) ??

3. What's the focal lenght when used on my K100D since I've heard that the 70-210 is for 35mm film and that it's different when used on a dSLR camera (and how do you calculate this ? so I can do it myself in the future).

4. I see it has a manual aperture ring and an A on that ring so I can eighter manually set the aperture with the aperture ring (to 22 for example) or put the ring in A and have the camera set the aperture ? correct ?? (I think I've set the menu of my K100D to allow manual aperture setting with the aperture ring).

5. How does this lens compair to the newer DA lenses like the : Pentax SMC-DA 50-200mm F:4.0-5.6 ED and the new Pentax SMC-DA* 50-135mm F:2.8 ED IF SDM

or in other words, if I have the Pentax A 70-210mm would there be a good reason (so not because of LBA) to get eighter of both of the above lenses aswell ?

I've been reading that the cheapest (Pentax SMC-DA 50-200mm F:4.0-5.6 ED) is a good overall lens but I would think that the 70-210 would cover most of the range of that one with a similar speed.

The more expensive DA* lens on the other hand has a smaller focal lenght but is faster with a lower aperture 2.8 instead of 4/5.6

A lot of questions I know but I'm trying to learn something about this lens.

TaoMaas · 11-21-2007, 08:19 AM

With one-touch zooms (like the one you purchased), sometimes there can be a tendency of the focus/zoom ring to slide slightly (or "creep") when you are pointing the camera up or down at a subject. This causes the lens to zoom a little bit, which changes your composition. It's not a huge consideration if most of your shots are hand-held, but it can be pretty irritating in other situations, like trying to shoot a long exposure of a flower, for example.

Cloudy Wizzard · 11-21-2007, 09:04 AM

Originally Posted by TaoMaas

With one-touch zooms (like the one you purchased), sometimes there can be a tendency of the focus/zoom ring to slide slightly (or "creep") when you are pointing the camera up or down at a subject. This causes the lens to zoom a little bit, which changes your composition. It's not a huge consideration if most of your shots are hand-held, but it can be pretty irritating in other situations, like trying to shoot a long exposure of a flower, for example.

so this lens has no focus ring and a zoom ring but just 1 ring that combines both ?

I was wondering where the focus ring was when I saw the picture of the lens in the review section here but I never would have guessed this.

so how does this work since I assume you will still need to focus on your subject when zooming in or out because the subject can vary in distance from the photographer ???

TFTM · 11-21-2007, 09:18 AM

Originally Posted by Cloudy Wizzard

As I just told Tom here I recently (monday evening) bought a Pentax zoomlens from a seller on Ebay (local Belgian).

since this is my first lens (not counting the 18-55 kit lens) I have some questions and I hope some here are able to answer them for me (but I'm quite sure they will).

The seller calls it a "SMC PENTAX- ZOOM A 1:4 70-210mm , 32 tot 4" in as good as new condition. So I've been looking at the lens review section here on the forums and I'm happy to see that most (of not all) reviewers would recomend this lens so I guess it's a fairly good one.

now here are the questions I have about it :

1. what do the reviewers mean with "zoom creep" or plain "creep" ? is that something to worry about ?

2. I assume this lens has the standard K Bayonet mount (will fit on my K100D Super without trouble) ??

3. What's the focal lenght when used on my K100D since I've heard that the 70-210 is for 35mm film and that it's different when used on a dSLR camera (and how do you calculate this ? so I can do it myself in the future).

4. I see it has a manual aperture ring and an A on that ring so I can eighter manually set the aperture with the aperture ring (to 22 for example) or put the ring in A and have the camera set the aperture ? correct ?? (I think I've set the menu of my K100D to allow manual aperture setting with the aperture ring).

5. How does this lens compair to the newer DA lenses like the : Pentax SMC-DA 50-200mm F:4.0-5.6 ED and the new Pentax SMC-DA* 50-135mm F:2.8 ED IF SDM

or in other words, if I have the Pentax A 70-210mm would there be a good reason (so not because of LBA) to get eighter of both of the above lenses aswell ?

I've been reading that the cheapest (Pentax SMC-DA 50-200mm F:4.0-5.6 ED) is a good overall lens but I would think that the 70-210 would cover most of the range of that one with a similar speed.

The more expensive DA* lens on the other hand has a smaller focal lenght but is faster with a lower aperture 2.8 instead of 4/5.6

A lot of questions I know but I'm trying to learn something about this lens.

I bought this lens not too long ago, perhaps I can answer your questions. If you want any pictures from this lens, let me know.

1. This means that the sliding mechanism that is used for zooming the lens has become worn and depending on how bad it is, the lens may shift focal length a little bit on extreme angles or may not even hold the desired focal length. My A 70-210 has a little bit of zoom creep and it hasn't bothered me at all.

2. Yup, mounts perfectly.

3. The crop factor of our cameras is 1.5, (technically 1.53x). Thus the 70-210 becomes a 105-315.

4. Your correct but there's a catch. With the A lens you can control the aperture of the lens from the camera body. Using the aperture ring on the camera is allowed but the lens cannot communicate what aperture you have manually set it to. This can lead to exposure problems. Since your prospective lens is an A lens, my suggestion is to change the aperture from the body.

5. I'll say this, if your considering the DA* 50-135, get it. Out of the trio of tele zooms you have presented it is by far the better one. It is also very expensive at ~900 US. However, if your choice at present lies between the 50-200 and 70-210 it's a toss up. They're both very good in terms of IQ. My A 70-210 has very sharp and I've heard equally good things about 50-200.

There are four main differences that can sway your decision one way or the other.

Focal range - The DA is slightly wider, do you need it?
Auto Focus - One lens is MF one is AF.
Constant Aperture - The DA variable between 4-5.6 where as the A is a constant F4.
Weight - The A series zoom is heavy. The DA is lightweight.

I ended up selecting the A 70-210. Good luck with your choice.

-Rajiv

Edit: To focus with a one touch zoom. You push-pull to change the focal length and twist to focus on your subject.

TaoMaas · 11-21-2007, 09:18 AM

You push or pull the ring to zoom and twist it to focus. It's a lot quicker way to operate than having separate zoom and focus rings, but the drawback is that sometimes you have the "creep" that you were asking about. The reason we don't hear as much about "zoom creep" these days is because auto-focusing pretty much did away with one-touch zooms.

Cloudy Wizzard · 11-21-2007, 10:12 AM

Originally Posted by TFTM

5. I'll say this, if your considering the DA* 50-135, get it. Out of the trio of tele zooms you have presented it is by far the better one. It is also very expensive at ~900 US. However, if your choice at present lies between the 50-200 and 70-210 it's a toss up. They're both very good in terms of IQ. My A 70-210 has very sharp and I've heard equally good things about 50-200.

There are four main differences that can sway your decision one way or the other.

Focal range - The DA is slightly wider, do you need it?
Auto Focus - One lens is MF one is AF.
Constant Aperture - The DA variable between 4-5.6 where as the A is a constant F4.
Weight - The A series zoom is heavy. The DA is lightweight.

I ended up selecting the A 70-210. Good luck with your choice.

Well maybe in time I will get the DA* but like you said, it's pretty expensive so I'll probably wait and see if I feel the need for this lens in the future.

so It's pretty much like I thought in terms that the A and DA are similar enough to choose eighter one. Since I'm waiting for the A 70-210 to arrive (probably somtime next week since the seller is now waiting to ship after my payment arrived and bank transfers are fairly slow around here) I will probably not need to look around for the DA lens and as I understand it the constant aperture of f4 is better for outside animal photography ?.

And even with the Kitlens I've got it set to MF for about 99% of the times so Auto Focus is not really a selling point at the moment so I guess the only downside of the A lens is the heavier weight (what is the weight of the lens ?).

Oh, and some pics with this lens to see the quality would be nice (I was wondering what would be a good way to test the quality of the lens once I have it).

thanks for the explenation.

Cloudy Wizzard · 11-21-2007, 10:13 AM

Originally Posted by TaoMaas

You push or pull the ring to zoom and twist it to focus. It's a lot quicker way to operate than having separate zoom and focus rings, but the drawback is that sometimes you have the "creep" that you were asking about. The reason we don't hear as much about "zoom creep" these days is because auto-focusing pretty much did away with one-touch zooms.

now that makes it all clear !

Thanks !!

*borno* · 11-21-2007, 11:13 AM

Here's a quick one cause i've only got a min. I think it was at 210mm

pentkon52 · 11-21-2007, 12:21 PM

I have had the A70-210 F4 for several years now, maybe six or seven. Its a great lens and does 1:4 macro to.

I have taken several flower macro shots with it, and the results were great. Mine suffers from some zoom creep and the focus is a bit loose for my taste, but i work around it, so no big deal. There are some small screws somewhere to tighten this, but I have yet to find them.

I think you'll enjoy this one.

Dave

TFTM · 11-21-2007, 12:36 PM

Originally Posted by Cloudy Wizzard

Well maybe in time I will get the DA* but like you said, it's pretty expensive so I'll probably wait and see if I feel the need for this lens in the future.

so It's pretty much like I thought in terms that the A and DA are similar enough to choose eighter one. Since I'm waiting for the A 70-210 to arrive (probably somtime next week since the seller is now waiting to ship after my payment arrived and bank transfers are fairly slow around here) I will probably not need to look around for the DA lens and as I understand it the constant aperture of f4 is better for outside animal photography ?.

And even with the Kitlens I've got it set to MF for about 99% of the times so Auto Focus is not really a selling point at the moment so I guess the only downside of the A lens is the heavier weight (what is the weight of the lens ?).

Oh, and some pics with this lens to see the quality would be nice (I was wondering what would be a good way to test the quality of the lens once I have it).

thanks for the explenation.

It's not necessarily that a faster lens is better. I like constant aperature lenses because I don't have to recompose my exposure settings as I zoom. That was a deciding factor in my lens choice. The 1:4 Macro is an added bonus as well.

I haven't measured the weight of the lens but it is fairly substanial since it's all metal. That being said it isn't unweildly but it's noticeable. A battery grip would help in balancing it out.

I'll try to get some pictures up tonight.

*borno* · 11-21-2007, 02:22 PM

Here's another patrick,

Click on the image to view it in a larger size

It's really a nice lens, I really lucked out and found one at a pawn shop in really nice shape (after cleaning the outside).

kjao · 11-21-2007, 05:41 PM

If you don't mind manual focusing and the weight, then go for the A70-210/4. Optically I believe it is beter than DA50-200 and F70-210. I used to own the A70-210 and only sold it because it is a little too heavy to carry around everyday and is a little unbalanced on my small DS.

cheers
Kenny

roy · 11-21-2007, 08:18 PM

Originally Posted by pentkon52

I have had the A70-210 F4 for several years now, maybe six or seven. Its a great lens and does 1:4 macro to.

I have taken several flower macro shots with it, and the results were great. Mine suffers from some zoom creep and the focus is a bit loose for my taste, but i work around it, so no big deal. There are some small screws somewhere to tighten this, but I have yet to find them.

I think you'll enjoy this one.

Dave

this is a GReat lens!
set the cam to Av and set the aperture what you want. push/pull and focus and take the shot. this is one of my most used lenses.

pentkon, there are 3-4 small screws you will see in you roll the rubber grip closest to the aperture ring(rear of lens) back about 1/2'', 12mm.. tighten these and it will fix the wobble of the zoom/focus ring. it does nothing to the creep. one way to fix the creep is to get a Wide rubber band, slightly smaller than the diameter of the zoom/focus ring and place it half on, half off of the ring so it's in contact with the barrel of the lens also.

ddhytz · 11-22-2007, 12:39 AM

Originally Posted by roy

one way to fix the creep is to get a Wide rubber band, slightly smaller than the diameter of the zoom/focus ring and place it half on, half off of the ring so it's in contact with the barrel of the lens also.

Have I got a Pentax 'L' lens by doing that?

Seriously, I need a WIDER rubber band and place it on the other end of the focus/zoom ring.

pentkon52 · 11-22-2007, 04:43 AM

Originally Posted by roy

pentkon, there are 3-4 small screws you will see in you roll the rubber grip closest to the aperture ring(rear of lens) back about 1/2'', 12mm.. tighten these and it will fix the wobble of the zoom/focus ring. it does nothing to the creep.

I have been told this, but have yet to find them.

Dave