[VictorDA]

Hello all,
So I spent a bit of time comparing these 2 cheap old AF zooms, looking for the best (or least bad) one to use with my new-to-me K-1, and thought I would share the results since I wasn't able to find any discussion about that anywhere (I didn't want to get the 28-105 right away, for simple budget reasons):

F 35-135, bought used for €25, in correct condition (some dust)
vs
FA 28-70, bought used for €30, in good condition (no dust, no element separation)

I was originally attracted to each lens for different reasons:
F: excellent range for daily family activities, relatively fast aperture, limited weight
FA: tried it before on APS-C and liked it, constant f/4, very small and light

Then I started to wonder if I should keep only one? I must admit that I was quite biased towards the FA, and thought it would outclass the old F based on the images produced in real life conditions before.
However, the results of this quick and dirty test (in my backyard, under natural lighting) showed a more nuanced reality.
The FA is indeed all in all a more balanced lens across the zomm and aperture ranges. It has a more neutral and modern rendering (blueish cast, smooth oof areas).
On the other hand, the old and ugly F lens has more character but hold its own. It has a disctinct old-style yellow cast (similar to M lenses) which is not unpleasing; it seems also slightly more sharp on the focus plan; however, its big issue is with oof rendering. The bokeh is quite harsh, with too much irregularity and too many highlights. It is especially not recommandable at 35mm, better in the 50-70mm range. Note that I have not tested the long end, I just wanted to compare the common range of both zooms (35-70mm).

In summary, I prefer the FA at 35mm and at wider apertures (at least up to 5.6), and tend to prefer the F at 70mm and at smaller apertures (11-16), but even in the ranges where both are "equivalent" the images produced will be well different!
If the topic is of interest to anyone you can look at the pics (35-50-70mm, f/4 to f/16): Microsoft OneDrive - Access files anywhere. Create docs with free Office Online.

[TwoUptons]

I've found the F series lens to be really annoying.
They are ugly, and the ergonomics are terrible.
Some of them are not very well built and occasionally come apart catastrophically despite no apparent damage.
But then it turns out some of them are quite good, optically.
Even some of the cheap ones...
The couple I still have I am quite fond of.

-Eric

[RICHARD L.]

Je n'ai jamais essayé le FA 28-70 mm f/4 sur mon K1 mais il est très bon sur mon K3. (I never tried the FA 28-70 mm f/4 on my K1 but it is very good on the K3.)





Le seul F que je possède est le F 70-210 mm f/4-5.6 et je dois avouer qu'il est extrêmement performant, même sur le K1. (The F 70-210 mm performs really well, even on a K1.)



Bien à vous ! (Regards)

[jimfellows]

Just to be different, I always liked the old power zoom FA 28-105. They can be picked up quite inexpensively.

Jim

[mgvh]

The Tamron 24-135 is my choice for an inexpensive FF zoom, and it goes a little wider to boot.

[boriscleto]

Just to be different, I always liked the old power zoom FA 28-105. They can be picked up quite inexpensively.

Jim

I have both the F 35-135 and the FA 28-105 PZ. Both are good lenses for the price...though I haven't used either one in years...

I've had two copies of the 28-70/4, neither one was useable. One was so badly fogged you couldn't see through it.

[garywakeling]

I just spent a month with the Single lens challenge using the F 35-135 on the K1, it delivered strong colours, had a handy range for day to day shooting and I would highly recommend it.
Some photos here

Single in April 21 SMC PENTAX-F ZOOM !:3.5-4.5 35-135mm | Flickr

[AfterPentax Mark II]

For the prices you paid it is, as they call it, a no-brainer. Of course keep them both. Each one has its use as you described it. If it were lenses you could sell for an interesting sum of money, but they are not. The FA 28-70 is a very usable lens that I bought in 1996 just after it was released and it came with my MZ-5 as being the new "standard" lens (as Pentax recommended it). It is still a beautiful lens with no problems like borisleceto described. I never like the build quality of the FA series, too much plastic. The build quality of the F series I liked much more which looked a bit plastic, but were genuine metal. The F70-210 mentioned before is a good lens, but it is heavier than it looks like. The 28-70 is a nice light one.

[photoptimist]

Nice reviews.

I'd think that BOTH lenses are essential to keep. For some subjects (big landscapes, tall buildings, small rooms), wider angle lenses are essential so you need the 28mm end. For other subjects (skittish creatures, sporting events, distant details), telephoto lenses are is essential so you need the 135mm end.

Of course, that pushes one toward getting a super-zoom (such as a 28-200) but then you end up with a bigger lens, slower aperture, and worse optical performance. Or one goes the route of a big bag full of primes to cover a full range of focal lengths but then you have to carry it all and spend time swapping lenses. ARGH!

One of the biggest challenges in photography is finding the right compromise(s) in focal lengths, apertures, size, handling, and cost.

(And it's all a great excuse for buying more lenses! )

[UncleVanya]

I used the 35-135 for many years as my main standard zoom on a pz-1. I felt it was pretty compromised at both ends of the zoom range and the lack of a dedicated hood was probably one of the reasons it was not the best performer. The range was handy and I did make some good images on it at times. But overall my impression of the lens was pretty low. Interesting to see different opinions.

[VictorDA]

Thanks for all inputs

F series lens [...] are ugly, and the ergonomics are terrible.

Subjective I know, but I find it hard to disagree

Je n'ai jamais essayé le FA 28-70 mm f/4 sur mon K1 mais il est très bon sur mon K3

N'hésitez pas à essayer, pour des photos "sans enjeu particulier", il est assez agréable à utiliser. Il souffre peut-être un peu plus que sur APS-C (mais dans mon cas c'était il y a déjà quelques années, sur K-5).

For the prices you paid it is, as they call it, a no-brainer. Of course keep them both.

(And it's all a great excuse for buying more lenses! )

Indeed and indeed again! I am not new to photography or Pentax, just the FF format; in 2021 it's finally possible to move to full frame quite inexpensively, especially when one already owns a few old primes

Anyway, the real bottom line is probably that exposing these zooms' weaknesses made me want to get the DFA 28-105 more, as I think this one would outclass both tested lenses. I initially thought I could skip it, but oh well... Just need to borrow one first to check the difference by myself!

[RICHARD L.]

Impossible de se tromper avec un DFA 28-105 mm HD sur un boîtier K1. Comme disent les Anglais : "Way to go !"

[mikesbike]

As Richard says, the best by far all-around zoom lens for the K-1 is indeed the DFA 28-105mm. I have it and glad I decided to get it. I have some very fine FF lenses from my film-shooting days, but I found the DFA 28-105mm attractive for its fine imaging reputation and its WR build quality. Its silent AF is nice too. A camera with WR construction is not WR active unless there is a WR lens on it. I still like my Tokina 28-70mm f/2.6-2.8 EX Pro II lens when I need that aperture range, and its imaging quality is excellent, but otherwise the DFA 28-105mm f/3.5-5.6 is also an excellent performer, and lighter for carrying with more zoom range.

The FA 28-70mm f/4 is a constant-aperture lens that was well-regarded in lab tests and with film during the 1990's. It is very light and small for carrying- a primary advantage. As photoptimist says, the F 35-135mm is handy for casual shooting when you need more zoom range to avoid lens-changing, while premium quality imaging is not all that important.

[leekil]

The FA 28-70mm f/4 is a constant-aperture lens that was well-regarded in lab tests and with film during the 1990's. It is very light and small for carrying- a primary advantage. As photoptimist says, the F 35-135mm is handy for casual shooting when you need more zoom range to avoid lens-changing, while premium quality imaging is not all that important.

I liked the 28-70 a lot back in the day, but it got the element fogging. I haven't been able to find another without that problem, but at one point I stopped looking.

---------- Post added 06-05-21 at 06:05 PM ----------

Impossible de se tromper avec un DFA 28-105 mm HD sur un boîtier K1. Comme disent les Anglais : "Way to go !"

It seems to have a lot of CA/purple fringing on the water in that canoe photo. Is that common?

[Bertrand3000]

Impossible de se tromper avec un DFA 28-105 mm HD sur un boîtier K1. Comme disent les Anglais : "Way to go !"

On that first canoë shot, there is this purple reflection on the bottom (like someone else noticed) and also those weird star-shaped reflections on the water here and there. Did you use some kind of filter, or post-processing to get those effects?