[switters]

I'm still trying to decide between keeping my K-x, upgrading to a K-5, or going back to a Canon 5D. I mostly take pictures of people. I'm expecting a child in a few months so of course that will become a focus. IQ, low-light ISO and AF-speed are most important to me. Other bells & whistles not so much. Video is a nice bonus, but I have a dedicated video camera so not essential. Lens selection at the following effective focal lengths is also very important:

- 50mm
- 100mm
- 28-75mm

I previously had a 5D with 50/1.4, 100/2 and Tamron 28-75/2.8. It was perfect for me - met all of the needs I described above - except that it was an incredible dust magnet. I sold that gear for mostly personal/financial reasons, and when I recently decided to get back in to photography I bought a K-x + 50/1.4 because I couldn't afford another 5D.

Things are better now financially, so I have a little more flexibility. I have about $2,000 to spend. My choices are:

- Stick with the K-x. Sell 50/1.4 (@$300) and get the Sigma 30/1.4, Pentax DA70/2.4 or FA77, and Sigma or Tamron 17-50. Cost: $1,500 - $1,800 depending whether I get the DA70 or FA77.

- Upgrade to K-5. Sell K-x & 50/1.4 (@$700) and get only Sigma 30/1.4 and DA70 for now. Cost: $1,700.

- Sell my K-x & 50/1.4 (@$700) and get a 5D with 50/1.4, 100/2 & Tamron 28-75. Cost: $1,300.

From a sheer cost perspective, seems like the last option makes the most sense. A full-frame, great IQ, good high ISO body with three excellent (not "L" quality, but all highly regarded) and fast lenses. The 5D's AF speed with these lenses was very good. Main hesitation here is the dust magnetism of the 5D. It was a constant problem, and very irritating.

I'm uncertain as to whether upgrading to a K-5 is worth the extra cost from a K-x, considering my needs. The K-x has fine IQ and its high ISO stands up quite well to the K-5 from what I've seen. I'm not entirely pleased with the AF performance (at least with my 50/1.4), so that's one potential reason to upgrade.

But as much as I've enjoyed Pentax, the issue is that it seems the Canon lenses available at the focal lengths I need and the price I can afford are higher quality and/or faster than the Pentax equivalents. For example, the 50/1.4 is only about $330. The closest equivalents would be the Pentax 35/2.4 (too slow for me) and the Sigma 30/1.4 (more expensive, and focus issues with some copies). At 100mm, Canon has the excellent 100/2 for just over $400, whereas Pentas has the DA70/2.4 (slower, more expensive) or the FA77 (faster, much more expensive). The 28-75 EFL zooms are all about the same price, so it's a wash there.

Since narrow DOF is a consideration (I like the artsy people shots with very blurred backgrounds), the 5D becomes even more attractive. In addition to the lenses being faster, there's the additional stop of DOF because of full-frame.

I know it sounds like I'm talking myself into the 5D. And maybe I am. But I wanted to see if you have any insight or thoughts.

[Impartial]

My $.02: if depth of field is more important to you than image quality, then Canon is a better choice. Let me explain: DA 35/2.4 and DA 70/2.4, with a K-5, will by all accounts give you better image quality than your Canon set-up, at the same price point you describe. But you will not have your f1.4 or f2 for shallow depth of field (losing 1.5 stops at normal and .5 stops at near tele). You can make up the low-light or high-speed performance through high-ISO, but not the depth of field.

So, depth of field or image quality? Only you can decide.

[Kryosphinx]

If Canon is going to suit your needs better, it's okay to switch back! No hard feelings!
Just never show your face around here again. ;D
I kid, use what works best for you!

Some comments from me:
Where are you getting a 5D and lenses for $2000???

The Tamron 28-75mm is available in Pentax mount, I think.

Pentax has a phenomenal DFA 100mm f/2.8. Sure, it's half a stop slower than the Canon and more expensive, but it garnered an astounding 9.9/10 rating in the Lens Database.
And you can shoot macros with it!
The bokeh (for your artsy shots) looks great too.

I've heard the K-5 has much better high-ISO and AF than any previous Pentax...

I personally am in love with Pentax primes, especially the legacy primes. I'd never give that up.
If you'd ever consider MF, tou may be able to find the legendary 50/1.2 for exceedingly narrow DOF


Good luck!

[switters]

Thanks both for your replies.

Impartial: what leads you to the conclusion that the IQ of the K-5 with 35/2.4 and 70/2.4 would be better than a 5D with 50/1.4 & 100/2? I'm curious, because the 50/1.4 and 100/2 are very well rated lenses on every review site, and the 5D IQ is pretty legendary - even now.

Kryosphinx: used 5D bodies go for $1,000-1,100 on Fred Miranda. 50/1.4 is $300 - $350 depending on used or new, 100/2 is about $380 - $430 and Tamron 28-75 is $380 - $460. I was planning on buying used gear if I go the Canon route - should have mentioned that. So, with a used 5D body and three used lenses it would cost me about $2,100.

Keep in mind that a 100/2.8 on Pentax is not remotely the same focal length as a 100/2 on a 5D. Much too long for indoor use. The DA70 and FA77 are my only Pentax choices in this focal range.

Thanks both for your replies.

Impartial: what leads you to the conclusion that the IQ of the K-5 with 35/2.4 and 70/2.4 would be better than a 5D with 50/1.4 & 100/2? I'm curious, because the 50/1.4 and 100/2 are very well rated lenses on every review site, and the 5D IQ is pretty legendary - even now.

Kryosphinx: used 5D bodies go for $1,000-1,100 on Fred Miranda. 50/1.4 is $300 - $350 depending on used or new, 100/2 is about $380 - $430 and Tamron 28-75 is $380 - $460. I was planning on buying used gear if I go the Canon route - should have mentioned that. So, with a used 5D body and three used lenses it would cost me about $2,100.

Keep in mind that a 100/2.8 on Pentax is not remotely the same focal length as a 100/2 on a 5D. Much too long for indoor use. The DA70 and FA77 are my only Pentax choices in this focal range.

I would say the K-5 comes close buy still won't beat overall IQ of the 5Dc. Also those lenses you picked would be amazing for the 5D, but you know that. I'm not exactly why the 5D would be a dust magnet. That would be more a lens issue than a body one. Just get a high quality filter and that should get rid of the dust problems.

[switters]

I was getting massive amounts of dust on the sensor, to the point where I'd have to clean it every week. And I wasn't shooting in bad weather or dusty conditions at all. After doing more research, I'm fairly certain there must have been a bad seal somewhere because other 5D owners don't have the same problem - at least not to the same degree.

But it was so irritating that I swore I'd never get another one at the time. The other issue with the 5D is that it's very limited in terms of future. I've really gotten used to the TAv mode and in-body SR on Pentax bodies, and while I'm not sure that's enough to sway me, it's a consideration.

[Ken T]

I would keep the 50mm f/1.4, sell the Kx then get the K-5 and the 100mm f/2.8 Macro. My FA 50 f/1.4 gets razor sharp when stopping down to f/2.8 and the 100mm always pleases me everytime I use it .

[elho_cid]

few thoughts:
1st - you can own Pentax and Canon in parallel as I do. Have the advantages of both.
2nd - K-5 is faster than 5D - useful with kids
3rd - K-5 is (as K-7 was) fairly resistant to dust.
4th - do not sell old camera before you buy the new stuff, keep choices open. The best practice is to only sell the gear that you don't use much.

[switters]

Thanks everyone. Ken T: the 100/2.8 sounds like a fantastic lens, but unfortunately on an APS-C it's too long for my needs.

Elho: with my limited budget, I'll have to sell old gear in order to afford gear. What you say makes sense, but it's not possible for me at present.

[switters]

Oops. Forgot to clarify something Elho said.

Is the K5 faster with AF than the 5D?

[elho_cid]

It is at least faster in fps.
I didn't do head to head comparison, but K-5 feels faster than EOS 30D (that I have at home) and that didn't feel slower than 5D for me (I held it last year only).
I believe focus speed is mostly matter of the lens and I'm not experienced with motst of the lenses you listed. But what the K-5 was doing with for example my Sigma 180mm EX Macro, that reminded me of the revelation when I held the D3. Astonishing speed.

5D, both of them, have horrible AF speeds. So I wouldn't be surprised if K-5 beat it. I am still waiting on a AF test. Haven't found any yet.

[switters]

Well, I used to have a K10D and a 5D, and I can tell you the 5D beat the pants off the K10D in terms of AF speed - at least with the lenses I had, which were the 50/1.4, 100/2 & Tamron 28-75 for the 5D, and various lenses including the 21/3.2 (fastest of the bunch), 35/2, 43/1.9, 50/1.4, 77/1.8 and 18-50/2.8 (Sigma) on the K10D.

Well, I used to have a K10D and a 5D, and I can tell you the 5D beat the pants off the K10D in terms of AF speed - at least with the lenses I had, which were the 50/1.4, 100/2 & Tamron 28-75 for the 5D, and various lenses including the 21/3.2 (fastest of the bunch), 35/2, 43/1.9, 50/1.4, 77/1.8 and 18-50/2.8 (Sigma) on the K10D.

Well, I am comparing it a 7D so it's slow compared to that. I hope they shove the 7D AF system or newer into the mark. Now that's a dang good camera there.

[Impartial]

Well, I haven't used the 5D Mk II, but am basing my impressions on the pictures I've seen and the measured increase in dynamic range the K5 represents -- most of which is additional shadow detail. There is a thread elsewhere making this comparison as well, and it seems that on a body basis, the 5D advantage on resolution is outweighed by its lesser dynamic range.

As far as lenses are concerned, I have no personal experience with any of the lenses in question. But I have personal experience with the FA 35/2, the DA 40/2.8, and the FA 77/1.8 . Based on what I have seen from the DA 35/2.4, I see it as an improvement over the FA in image quality (better bokeh especially), and intend to "downgrade".

As for the DA 70, I simply compare it to the FA 77. While half a stop slower and with less 'pixie dust', it also has fewer chromatic aberrations. So I would call the image quality itself 'comparable'. And given the overall reputation of the Pentax 'limited' lenses, I have difficulty seeing the second strong of Canon lenses having an IQ advantage. YMMV.

P.S. sorry about my slow edits to this post -- my phone was uncooperative. It should all be in the right place, now.

Thanks both for your replies.

Impartial: what leads you to the conclusion that the IQ of the K-5 with 35/2.4 and 70/2.4 would be better than a 5D with 50/1.4 & 100/2? I'm curious, because the 50/1.4 and 100/2 are very well rated lenses on every review site, and the 5D IQ is pretty legendary - even now.

Kryosphinx: used 5D bodies go for $1,000-1,100 on Fred Miranda. 50/1.4 is $300 - $350 depending on used or new, 100/2 is about $380 - $430 and Tamron 28-75 is $380 - $460. I was planning on buying used gear if I go the Canon route - should have mentioned that. So, with a used 5D body and three used lenses it would cost me about $2,100.

Keep in mind that a 100/2.8 on Pentax is not remotely the same focal length as a 100/2 on a 5D. Much too long for indoor use. The DA70 and FA77 are my only Pentax choices in this focal range.