Pentax F 28-70 f/4 - opinions, samples?

[gkreth]

Well, I was looking for a constant f/2.8 medium zoom.

Now I'm thinking about the Pentax F 28-80 f/4. Some have called it the "poor man's FA* 28-70 f/2.8"."

Does anyone own one? What do you think of it? Can you post some samples?

What I'm looking for is something SHARP wide open. Since it's an f/4 and not an f/2.8, I know I'm sacrificing a stop of light. So, I would use it wide open most of the time. The cost of that additional stop is pretty steep, so I'm hoping the f/4 will work for me most of the time.

Thanks in advance for you opinions.

Greg

 

[essH]

Well, I was looking for a constant f/2.8 medium zoom.

Now I'm thinking about the Pentax F 28-80 f/4. Some have called it the "poor man's FA* 28-70 f/2.8"."

Does anyone own one? What do you think of it? Can you post some samples?

What I'm looking for is something SHARP wide open. Since it's an f/4 and not an f/2.8, I know I'm sacrificing a stop of light. So, I would use it wide open most of the time. The cost of that additional stop is pretty steep, so I'm hoping the f/4 will work for me most of the time.

I'm a bit confused - which lens do you mean? I checked on the listing at Boj's site

http://www.bdimitrov.de/kmp/lenses/zooms/short/index.html

and saw several lenses you might be talking about.

Anyway, in case it's the FA 28-70 f4 you're asking about, yes, I have one - I used it a lot for a while. It's a perfectly adequate lens - what some call a consumer lens (in other words there's plastic around and the quality is not the highest). It's very light and easy to use. I didn't use it wide open very much, but it produced reasonable images for what I wanted. I replaced it with a DA 16-45. I wouldn't call it the poor man's version of an FA*, though.

--
Simon
long time Pentax user

 

[kathyk]

I don't have it, but here are some pbase photos.

Some look very good, I think if you can shoot the right things in the right way with this lens, it seems to produce some very pleasing results.

http://www.pbase.com/cameras/pentax/smc_pfa_28-70_4_al

--
-Kathy

 

[stewartpratt]

Does anyone own one? What do you think of it? Can you post some samples?

I've got one (that's a lie - I've got two - it's so good I bought another as a spare, just in case...), I've had it since film camera days, and it's an excellent lens. Though sadly I won't get a chance to post samples anytime soon.

What I'm looking for is something SHARP wide open. Since it's an f/4 and not an f/2.8, I know I'm sacrificing a stop of light.

I pretty much always use it wide open, and to my eyes it's not far off the sharpness of my 35mm f/2, which is well known as a sharp lens.

--
http://flickr.com/photos/stewartpratt/

 

[steephill]

This lens is notorious for element separation so look out for that.

--
Steve

http://www.pbase.com/steephill

 

[Joseph Tainter]

If this is the old FA 28-70 F4, the image quality is okay but it has a reputation for falling apart. I would avoid it.

Joe

 

[essH]

This lens is notorious for element separation so look out for that.

Ah, yes - good point; I'd forgotten about that.

I just checked some samples I'd taken when I first got this lens, and I'd have to say that the ones that were taken at f4 are generally not wonderfully sharp; they're ok - just not crisp. The lens is definitely better stopped down a bit; I have a number of shots (not currently anywhere online) that are very pleasing in terms of light and colour and I was happy with the lens for several months until I could afford something more expensive.
--
Simon
long time Pentax user

 

[waynelr]

Have you looked at the Tamron 17-50? I'm getting one soon and believe it to be as sharp as anything out there at either end and wide open. I'll be testing one the next few weeks.

Wayne's World of Graphics & Barbershop
http://public.fotki.com/waynelr6/
http://waynelr.smugmug.com/

 

[loock]

Sorry for reminding this, but ... FA 28-70 f 4 developing lens separation problem, ring any bell ?

 

[Roland Mabo]

I used to have the FA 28-70 f/4 but I replaced it with the FA 28-105 f/3.2-4.5 AL (IF).
In terms of sharpness, they were close.
In terms of contrast, the FA 28-105 won.
In terms of distorsion, the FA 28-105 had lower.

In terms of vignetting, the 28-70 f/4 had high vignetting at 28 and f/4 on 24x36 but you will notice it less on APS-C.

Pentax replaced the 28-70 f/4 with the DA 16-45 f/4 for APS-C and this one is a better lens.
--
Take care
R
http://www.flickr.com/photos/raphaelmabo

 

[Wallace Ross]

I have the FA 28-70 f-4

Well it's an inexpensive lens, it actually isn't too bad optically on par with the kit lens which is decent. It does have some CA and purple fringing under extreme situations but is generally sharp beyond f5.6.
The bonus for me is I can slap it on my PZ1-p as well.

I use it as an alternative walk around when I want a bit longer.
works out to 42-105mm

These two shots were taken with it.

http://forums.dpreview.com/forums/read.asp?forum=1036&message=35331160

 

[gkreth]

I want to thank everyone for replying, especially the comments about the lens separation.

I don't know if it's any help, but here's some background on why I asked:

I just recently bought a Sigma 28-70 f/2.8. It's OK, but softer than I expected/wanted it to be when wide open. It gets better at f/4, and it quite nice by f/5.6, but I really didn't want to have to stop it down so much to get the sharpness I wanted.

I'm actually looking for a true mid-tele zoom on an APS-C format, i.e., I'm not interested in a 16-45, or 17-50, or 17-70.

In reality, when and where I would use this lens, the perfect focal length for me would be 40-150mm (i.e., 60-225mm in APS-C) f/2.8. Unfortunately, such a beast does not exist.

Here are other lenses I have considered:

• DA 60-250 f/4: Nice, but WAY** too expensive for me
• DA 50-135 f/2.8: Also nice, but again, a bit too expensive for my budget. Also, the 50mm is just a tad too long for the "wide end" I would want in these situations. Last, the 135mm long end is OK, but if I could get a little bit more....
• Sigma 50-150 f/2.8: So far, the one closest to my needs. A bit less expensive than the DA 50-135, but still pretty pricey for me, personally. (Looks like it sells for about $700.) And, the 50mm wide end is just a little bit too long for the "wide end."

So, the 28-70 is already a compromise for me on the long end, I realize that. With the lens separation issue. I will take this lens off my list.

Roland, I would like to find an FA 28-105 f/3.2-4.5; although it's not quite long enough, with some cropping I could probably make it work. And true, the f/4.5 is creeping up into the not-as-fast-as-I-want area, I can't see to find exactly what I would like.

Ah, if only Pentax had made the 28-135 f/4 in an AF version; that would be a VERY nice lens to own! At a 1.5 crop FOV of 42-203mm, and a constant f/4 aperture, an AF version of that lens would have been VERY nice!

The K 45-125 f/4, if it had been made in an AF version, would also have been nice; not as nice as an AF version of the 28-135 f/4, but nice nonetheless!

Not sure where to go now, on this. I guess I could keep an eye out for an FA 28-105 f/3.2-4.5, or just start saving up for a Sigma 50-150.

Greg

 

[ManuH]

Did you consider the Tamron 28-75mm f/2.8? It's highly regarded.

--
Manu



http://flickr.com/photos/ensh/
Réflex Pentax: http://www.flickr.com/groups/pentaxfr/

My PPG: http://www.pentaxphotogallery.com/home#section=ARTIST&subSection=1312871&subSubSection=3929608

 

[JensR]

Hi Greg!
Have you considered the Tamron and Sigma 24-135?

They are big and not perfect, but might be worth checking out?

Cheers
Jens

--

'Well, 'Zooming with your feet' is usually a stupid thing as zoom rings are designed for hands.' (Me, 2006)
'I don't own lenses. I pwn lenses.' (2009)
My Homepage: http://www.JensRoesner.de

 

[stewartpratt]

I have the FA 28-70 f-4

Well it's an inexpensive lens, it actually isn't too bad optically on par with the kit lens which is decent. It does have some CA and purple fringing under extreme situations but is generally sharp beyond f5.6.

I must have a good one - mine blows the kit lens away and I've not had any CA/fringing as far as I can recall.

Patchy quality control perhaps?

--
http://flickr.com/photos/stewartpratt/

 

[smarter]

Last year I bought a very cheap old Pentax zoom, the SMC F 35-70mm f/3.5-4.5. I paid € 49,- for it.

I bought it because it's incredibly small and light and still is just as fast as my huge and heavy Sigma 17-70mm f/2.8-4.5 at the same compared focal range (35-70mm).

I just thought it was fun to have a spare, small zoom lens for traveling light. Nothing more, nothing less.

Now, several months later I realize how underestimated this little gem really is; incredible Pentax colors, very fast AF and very sharp all the time. I love this lens.

I love it so much that I have a second sample just in case, and they are dirt cheap anyway.

some reviews at pentaxforumsdotcom/lensreviews at the F series zoom section.

My 2 F-buddys: The F 28mm f/2.8 prime (mounted on my K-x) and the F 35-70mm zoom.





3 random pics I took with this lens:

 

[essH]

Just a thought, Greg - how about the FA 24-90? I haven't seen any of those come up for sale recently, but they seem to have been highly regarded. It's f3.5 - 4.5, which might not suit you.
--
Simon
long time Pentax user

 

[Anastigmat]

You mean the 28-80mm f/3.5-4.5? It is a good lens, and few people know about it, so it is quite reasonably priced in the used market. Good buy if you can find one that is flawless.

Well, I was looking for a constant f/2.8 medium zoom.

Now I'm thinking about the Pentax F 28-80 f/4. Some have called it the "poor man's FA* 28-70 f/2.8"."

Does anyone own one? What do you think of it? Can you post some samples?

What I'm looking for is something SHARP wide open. Since it's an f/4 and not an f/2.8, I know I'm sacrificing a stop of light. So, I would use it wide open most of the time. The cost of that additional stop is pretty steep, so I'm hoping the f/4 will work for me most of the time.

Thanks in advance for you opinions.

Greg

 

[Anastigmat]

He is probably talking about the SMC-F 28-80 f/3.5-4.5 lens. There is also a very good SMC-FA 28-70mm f/4 lens, but that lens has problems with internal elements separating. Get a flawless sample, and the FA will perform well also.

Well, I was looking for a constant f/2.8 medium zoom.

Now I'm thinking about the Pentax F 28-80 f/4. Some have called it the "poor man's FA* 28-70 f/2.8"."

Does anyone own one? What do you think of it? Can you post some samples?

What I'm looking for is something SHARP wide open. Since it's an f/4 and not an f/2.8, I know I'm sacrificing a stop of light. So, I would use it wide open most of the time. The cost of that additional stop is pretty steep, so I'm hoping the f/4 will work for me most of the time.

I'm a bit confused - which lens do you mean? I checked on the listing at Boj's site

http://www.bdimitrov.de/kmp/lenses/zooms/short/index.html

and saw several lenses you might be talking about.

Anyway, in case it's the FA 28-70 f4 you're asking about, yes, I have one - I used it a lot for a while. It's a perfectly adequate lens - what some call a consumer lens (in other words there's plastic around and the quality is not the highest). It's very light and easy to use. I didn't use it wide open very much, but it produced reasonable images for what I wanted. I replaced it with a DA 16-45. I wouldn't call it the poor man's version of an FA*, though.

--
Simon
long time Pentax user

 

[zakaria]

Ihave fa 28-105 f 3,2.it.s good as a standard zoom.build quality is good.It costs me 80$ new not used.
--
k200d,da 10-17 fish eye,dfa 100macro,FA*200,da55-300

nikon300s,sigma 50 f1,4 sigma 180 macro,sigma 50-150,sigma 20-40,sigma 105,nikon af 85 d
fuji pro 5
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