[dgaies]

FA31 is 2.8 times more expensive than DA40 . It means that FA31 HAS to be 2.8 times better

No, that's actually not at all what it means

And for the last time, there is no way to fully define or quantify "better".

[robgo2]

No, I have seen scientific studies showing that the FA31 is only 2.089 times better than the DA 40. Only a fool would pay 2.8 times more for it.

[dgaies]

No, I have seen scientific studies showing that the FA31 is only 2.089 times better than the DA 40. Only a fool would pay 2.8 times more for it.

Damn! I hate being a fool!

edit: I just looked up what I paid for my 31 and my 40 (both purchased used), and I paid 2.81x more for my 31.... even more foolish!

[krendel154]

Unfortunately, replies of some members (dgaies & robgo2) is not so pleasant for me as a new pentaxian and as the person who create his first thread in Pentaxforums. I can see that both of you have a lot of posts in this forum. All of these posts are making fun at people? I think you know more than I know about photography but it doesn't give you right to make fun at new Pentaxforums member.

[Wheatfield]

I am trying to find out difference in pictures that produce DA40 and FA31. Because, I have checked DA and FA clubs and all members are so proud of these lenses. I can see the difference in price. But how to find the side-by-side comparison, which will prove that FA31 2.8 times better?

Have you ever heard of the law of diminishing returns?
It applies in this instance.

[dgaies]

Unfortunately, replies of some members (dgaies & robgo2) is not so pleasant for me as a new pentaxian and as the person who create his first thread in Pentaxforums. I can see that both of you have a lot of posts in this forum. All of these posts are making fun at people? I think you know more than I know about photography but it doesn't give you right to make fun at new Pentaxforums member.

Hardly. Please reread my initial posts in this thread. I merely pointed out that your question can't be answered.

[krendel154]

Have you ever heard of the law of diminishing returns?
It applies in this instance.

No, I don't know what does it mean.

[v5planet]

Unfortunately, replies of some members (dgaies & robgo2) is not so pleasant for me as a new pentaxian and as the person who create his first thread in Pentaxforums. I can see that both of you have a lot of posts in this forum. All of these posts are making fun at people? I think you know more than I know about photography but it doesn't give you right to make fun at new Pentaxforums member.

People around here can get cranky easily, but you shouldn't get defensive either. The way you phrased your question is making people pretty incredulous because it's impossible to objectively rate the quality of one lens against the other, and as Wheatfield said, even if it were, the Law of Diminishing Returns will rear its head. Namely, the quality of a product does not increase proportionally with every dollar added to its cost. Rather at some the cost balloons while quality increases more and more slowly.

I think you should be looking at this differently. The question you should be asking is: Are the things the FA31 can do that the DA40 can't worth it to ME to pay such a high premium? The answer to that question is definitely not the same for everybody. The 31 is a faster lens; it is a different focal length so would not be used the same way; and the characteristics of the images it produces are very different from the DA40. It's touted as one of the greatest lenses Pentax has ever made, and its price matches its luxury status. Would it be worth it to you? Well, I'm not sure anyone can answer that for you; all we can do is ask you pointed questions that can help you answer it for yourself.

The capabilities of a lens are independent of a photographer's ability to fully exploit them, so the difference a beginner will see between a good lens and a great lens is unlikely to be as obvious as the gulf a very talented and experienced photographer would create between good and great equipment that is pushed to its limits and fully utilized. In other words -- expensive lenses are expensive because they can often do things that less expensive lenses simply cannot. But how much more can they really do, and can YOU get the lens to do that?

[krendel154]

That's the fundamental problem with your question. You can easily quantify the difference in price between the two lenses. You can not, in any objective way, determine how much "better" one lens is than the other. If I need to shoot below f/2.8, the 31 is infinitely better (in that situation) than the 40. If I only want to shoot with a lens under 100g, then the 40 is is infinitely better (in that situation) than the 31. Obviously most people don't shoot exclusively below f/2.8, nor do people only shoot with lenses under 100g. But depending on what your priorities are will determine how much "better" one lens is over the other (for you). I own both, along with quite a few other excellent lenses. It would be futile for me to try and quantify exactly how much better lens A is than lens B, because it is entirely dependent on the situation and what you're looking to get out of the lens.

Ok, can you post pictures taken with this two lenses and the same settings, please?

[krendel154]

People around here can get cranky easily, but you shouldn't get defensive either. The way you phrased your question is making people pretty incredulous because it's impossible to objectively rate the quality of one lens against the other, and as Wheatfield said, even if it were, the Law of Diminishing Returns will rear its head. Namely, the quality of a product does not increase proportionally with every dollar added to its cost. Rather at some the cost balloons while quality increases more and more slowly.

I think you should be looking at this differently. The question you should be asking is: Are the things the FA31 can do that the DA40 can't worth it to ME to pay such a high premium? The answer to that question is definitely not the same for everybody. The 31 is a faster lens; it is a different focal length so would not be used the same way; and the characteristics of the images it produces are very different from the DA40. It's touted as one of the greatest lenses Pentax has ever made, and its price matches its luxury status. Would it be worth it to you? Well, I'm not sure anyone can answer that for you; all we can do is ask you pointed questions that can help you answer it for yourself.

The capabilities of a lens are independent of a photographer's ability to fully exploit them, so the difference a beginner will see between a good lens and a great lens is unlikely to be as obvious as the gulf a very talented and experienced photographer would create between good and great equipment that is pushed to its limits and fully utilized. In other words -- expensive lenses are expensive because they can often do things that less expensive lenses simply cannot. But how much more can they really do, and can YOU get the lens to do that?

Thank you for your answer.
If you guys feel incredulous, please, don't! I didn't mean it . Sorry!
When I got my k-x I already had 18-55 DA L on it but when my friend showed pictures taken with DA40 I fell in love and have payed $340 for this prime, which stay on my camera now most of the time and 18-55 laying on the shelf. So, probably, I would switch onto FA31. I prefer to have one very good prime lens on my camera most of the time instead of switching them. A lot of people telling that FA31 is luxury one. So, I was going to clarify it for myself. I will paraphrase my question how was suggested by v5planet):
" Are the things the FA31 can do that the DA40 can't worth it to ME to pay such a high premium?"
Sorry, again for misunderstanding

[dgaies]

Thank you for your answer.
If you guys feel incredulous, please, don't! I didn't mean it . Sorry!
When I got my k-x I already had 18-55 DA L on it but when my friend showed pictures taken with DA40 I have payed $340 for this prime which stay on my camera now most of the time and 18-55 laying on the shelf. So, I was wondering probably I would switch onto FA31. I prefer to have one very good prime lens on my camera most of the time instead of switching them. A lot of people telling that FA31 is luxury one. So, I was going to clarify for myself (I will paraphrase my question how was suggested by n5planet):" Are the things the FA31 can do
that the DA40 can't worth it to ME to pay such a high premium?" Sorry, again for misunderstanding

When I owned the 40 and decided to buy the 31, it was mainly for the extra width and aperture for shooting indoors. I found the 40 to be a little too tight indoors. I also found larger aperture when the lighting was less than ideal.

Obviously the biggest differences between the 31 and 40 are going to be the extra width, bigger aperture, larger size and higher cost of the 31. As I'm sure you know from using it, the 40 is tiny and had super fast AF. The 31 is going to feel a bit bigger on your K-x, although not to the point of being unbalanced. The AF will feel a bit slower than the 40, but I've never found either to be an issue in terms of AF speed.

I looked back to see if a comparison I did earlier this year of several different lenses contained both the 31 and 40 (link). Unfortunately I didn't have a 40 at the time so it didn't. That said, you might want to take a look anyway as it might give you an idea of what kind of differences you might can expect from lens to lens. The differences can be quite subtle. Keep in mind, all the shots were taken wide open, so not at a common aperture. Also, FYI, the 31 shots are posted later in the thread, although there's a link to them in the first post.

[krendel154]

Thank you for all of your replies, dgaies. I feel that atmosphere in this thread became wormer after v5planet and me had clarify my question.

[civiletti]

According to photozone's MTF test, the DA40 is better across the frame, while the DA31 is better in the center. The DA40 is smaller. The DA31 is faster.

[Frogfish]

According to photozone's MTF test, the DA40 is better across the frame, while the DA31 is better in the center. The DA40 is smaller. The DA31 is faster.

Actually it doesn't show that at all. it shows the 31 sharper in the centre only up to f4, after that, at more commonly used apertures, the 40 is sharper in the both the borders AND the centre.

krendel : for your uses you really need to ask yourself if you need the extra width and the extra low light ability of the 31, for instance if you shoot indoors a lot. If you don't then there isn't much point in buying the 31 unless you find the different rendering a major attraction.

If you just need the extra width and a faster lense than the 40 then you could consider the Sigma 30/1.4, which is 'cut your throat' sharp once stopped down a little (and still fine wide open) and only 1/3 the price of the 31 Ltd, but without the 'pixie-dust' of the 31.

[krendel154]

Yes, I take a lot of pictures indoor.