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09-02-2016, 11:20 PM   #1
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Fast normal, struggling with figuring out what would be optimal for ~$500

Hi all,

I am trying to get some shallow depth-of-focus shots with a normal perspective and I am thinking I might be better off with some other equipment.
At the moment my options for pentax are:
DA 40 F2.8, DA 50 F1.8 on K-3

Those are both ok, but the autofocus is unreliable below F2.8. As a result what I use instead is an olympus 45mm F1.8 on a micro four thirds camera (F2.4 equiv for APS-C).
It works very well, but I would like a bit less DOF.

Here are some things I am thinking of, trying to keep things below $500, all used:
- Canon 1D Mk ii or iii + 50mm F1.8 STM , or 50 F1.4
- Panasonic/Leica 25mm F1.4
- DA 55mm F1.4 (but AF might be troublesome?)
- Canon 5D/1Ds Mk I + 50mm F1.8 STM

or just be done with it all and get a sony A7 + Canon EF adapter + 50mm F1.8 (~$1300).

I quite like the idea of buying a high-end body even if it is old, for the sake of fun, but I am not sure if it is worth it, and maybe it's better to just shell money for an A7, or stick to MFT and pentax systems.

I would welcome some thoughts or suggestions on cameras/lenses I might have missed.

09-03-2016, 12:24 AM   #2
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Try the FA50 f/1.4 with your K-3 before you give up and switch out of Pentax. Personally, I prefer the DA50 f/1.8 in terms of outright IQ and rendering, but I understand what you mean about AF inconsistency - it's not always completely reliable (although do check that it's not you moving slightly that's resulting in focus inaccuracy - at shallow depths of field you do need to be very steady). A good used FA50 won't cost very much and is well worth trying, plus you can sell it on easily if it doesn't work out.

PS. The K-3 *is* a high end body - build quality is right up there with anything you'll find...
09-03-2016, 12:47 AM   #3
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QuoteOriginally posted by BigMackCam Quote
Try the FA50 f/1.4 with your K-3 before you give up and switch out of Pentax. Personally, I prefer the DA50 f/1.8 in terms of outright IQ and rendering, but I understand what you mean about AF inconsistency - it's not always completely reliable (although do check that it's not you moving slightly that's resulting in focus inaccuracy - at shallow depths of field you do need to be very steady). A good used FA50 won't cost very much and is well worth trying, plus you can sell it on easily if it doesn't work out.

PS. The K-3 *is* a high end body - build quality is right up there with anything you'll find...
I am thinking of buying something in addition to the K-3. I am just curious about the canon 1D series. I used the Nikon D2h in college and it was a fun camera. I don't think that FA50 F1.4 will be much better in AF. I think I would be best of either with a larger sensor (so F2.8 is lower DOF, but still can be focused properly), or by getting a mirrorless.

I guess another option would be to get a k-01 or a sony Nex 5 + the new sigma 30mm F1.4.
09-03-2016, 12:57 AM   #4
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Remember that for a "normal" field of view you want something between 28mm and 35mm for an APS-C like the K-3, and between 21mm and 28mm on micro 4/3

Fast, autofocus options are limited for Pentax APS-C cameras. The only Pentax choices are the FA31/1.8 and FA35/2.0. Sigma make a 30/1.4, 35/1.4 and a 18-35/1.8 zoom.

If you get a K-1 there are more options in the normal range. From Pentax, FA43/1.9, FA50/1.4, DA50/1.8 and DA*55/1.4 are still available, and the older F series has f/1.4 and f/1.7 50mm primes.


Last edited by Sandy Hancock; 09-03-2016 at 02:10 AM.
09-03-2016, 01:18 AM   #5
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Do you want a normal lens or a 85mm equivalent for APS-C? Because if you want that, I would recommend the DA *55 or FA 43 or even the Sigma 50mm f1,4 (used copy).

A "normal" lens on APS-C would be something in the 30-ish mm range.
09-03-2016, 01:19 AM - 2 Likes   #6
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QuoteOriginally posted by rrstuff Quote
I am thinking of buying something in addition to the K-3. I am just curious about the canon 1D series.
If you fancy trying one for fun, go for it. Just bear in mind that it is old technology - sensors have come an awfully long way since the original 1D, and most (all?) of those earlier models don't have anything like the dynamic range and high ISO performance of cameras such as the K-3.

QuoteOriginally posted by rrstuff Quote
I don't think that FA50 F1.4 will be much better in AF.
Can I ask, what leads you to believe that? I have both lenses, and the FA50 f/1.4 is consistently very accurate on AF, even at f/1.4. I agree that the DA50 f/1.8 can be a bit hit and miss at times, although it's by no means bad - but the FA50 f/1.4 has given me no problems with AF in the short time I've owned mine, and I've never heard reports of AF inaccuracy for this lens.

QuoteOriginally posted by rrstuff Quote
I think I would be best of either with a larger sensor (so F2.8 is lower DOF, but still can be focused properly), or by getting a mirrorless.
Are you absolutely confident you understand the relationship between focal length, aperture, distance, depth of field and perspective, as well as field of view for the same lens used on different sensor size cameras? The reason I ask this is that a 50mm lens shot at f/2.8 on two cameras, one APS-C and one "full frame", at the same distance, will have exactly the same perspective and depth of field... the sensor has nothing to do with this. What's different is the field of view - the APS-C sensor effectively chops off the top, bottom and sides of the scene you're photographing.

So, for the same lens shot at the same aperture, with the APS-C camera you'll have to move back to get everything in frame compared to the full frame camera, and that will result in greater depth of field and "compression" (perspective distortion) at the point of focus. Conversely, with a full frame camera, to get your subject filling the frame in the same way as the APS-C camera, you'd have to move toward the subject, resulting in shallower depth of field and less "compression" at the point of focus.

To get the same field of view between an APS-C camera and a full frame camera, when shot at the same distance, you'd need to use different focal length lenses.

Apologies if you already know what I've just described, but it does seem like you're not quite sure why you're considering different sensor size cameras and how that will affect your photography. I don't want you to make an uninformed choice and be disappointed or confused by the results you get
09-03-2016, 01:40 AM   #7
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QuoteOriginally posted by BigMackCam Quote
Can I ask, what leads you to believe that? I have both lenses, and the FA50 f/1.4 is consistently very accurate on AF, even at f/1.4. I agree that the DA50 f/1.8 can be a bit hit and miss at times, although it's by no means bad - but the FA50 f/1.4 has given me no problems with AF in the short time I've owned mine, and I've never heard reports of AF inaccuracy for this lens.
thanks. I am aware of all the details of the DOF. As for the FA50 F1.4 being no more accurate - it's the specification of F2.8 luminance flux sensors, they are not supposed to be accurate below F2.8.

And yes, I am aware that a 50mm will be longer than normal, but I can live with some wiggle room. A fast normal is the cheapest fast aperture lens one can buy, and I think can work with the field of view of a 50 on anything from FF, through APS-H, to APS-C. It will be for whole body portraits/fashion shoots and for pictures of dogs, and I can work within those focal lengths.

For the sake of precision:
I am looking for what are my options for reliable autofocusing of a lens with 40 deg FOV (+/- 10), which will roughly fit in 2 m object in the frame, with about 0.2 m depth of focus (0.03mm CoC).
This is basically what would a 45-75mm lens would look like on F2, on a full frame, 40-50mm at F1.8 on APS-H, or a F1.4 30-50mm on APS-C would be fine, too, but I am a bit hesitant about the phase-difference AF systems, and I am leaning either towards mirrorless, or an old FF camera.

Ideally, i would like to keep it below $500, unless buying a Sony A7 is just a much better idea. Perhaps it would be better to spend $1300 instead of wasting $500.
09-03-2016, 01:45 AM   #8
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QuoteOriginally posted by rrstuff Quote
Hi all,

I am trying to get some shallow depth-of-focus shots with a normal...
At the moment my options for pentax are:
DA 40 F2.8, DA 50 F1.8 on K-3

Those are both ok, but the autofocus is unreliable below F2.8. As a result what I use instead is an olympus 45mm F1.8 on a micro four thirds camera.
Da 40 has a 60mm field of view which is a little long for normal, the 50 acts like it is roughly 75, so it is a short telephoto effectively. The 45 on m43 acts like a 90, which again is not a "normal lens perspective".

Given your like for the 45 on m43, I'd suggest an fa77. This won't give a normal perspective, but none of your tested options did either.

09-03-2016, 01:59 AM   #9
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QuoteOriginally posted by rrstuff Quote
thanks. I am aware of all the details of the DOF. As for the FA50 F1.4 being no more accurate - it's the specification of F2.8 luminance flux sensors, they are not supposed to be accurate below F2.8.
Be that as it may, I speak from personal experience when I say that the FA50 f/1.4 consistently focuses with accuracy wide-open on my K-3, even at short distances where very shallow DOF is intolerant of AF inaccuracies. How it does that considering the PDAF points with f/2.8 accuracy, I don't know - but it works.

I could be wrong, but I don't believe the 1D series of cameras has PDAF points with accuracy greater than f/2.8, so I don't see any real advantage there, unless you simply use whatever lens you fit to it at f/2.8 or slower.

A mirrorless camera will give you more accurate AF by using contrast detection for all or part of the AF cycle. You could achieve this by using your K-3 in live view mode, of course, but it's not fast and you may not like using the LCD as your viewfinder (I've never liked live view, to be honest).

Personally, I recommend trying the FA50 f/1.4 - it's relatively cheap if bought used, and - regardless of your understandable doubts - it does accurately auto-focus on the K-3 (if you want proof, I'm happy to take some test shots for you). Plus it's easy to sell on if you don't get the results you're looking for. If, however, you're looking to try a different camera and lens setup (and it sounds like this might be what you really want, whether consciously or sub-consciously), I'd avoid the older high end bodies you were describing, as they're not going to offer any benefit in phase detect AF at wide apertures.

EDIT: One last suggestion... At the focal lengths you're talking about, manual focusing isn't such a chore. Do you absolutely need auto-focus for the types of shots you're after? The DA50 f/1.8 manually focuses well, or you could look at any number of manual-focus 50mm f/1.4 lenses. Technique in manual focusing will be much cheaper than any additional equipment

Last edited by BigMackCam; 09-03-2016 at 02:16 AM.
09-03-2016, 03:21 AM   #10
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I have had both the FA 50 f/1.4 and FA 35 f/2 before selling both off to acquire 3 DA Limited lenses and the D FA 100 f/2.8 macro WR. The 50 was a nice piece of glass but it was usually too narrow or not long enough for my shooting tastes. The 50 was tack sharp across the entire frame at f/2 - I found it soft wide open. I don't miss the 50 - the HD DA 70 replaced it.

On the other hand, the FA 35 f/2 is a very special piece of glass. It's tack sharp wide open, renders colours beautifully and is very quick to auto-focus. Parting with it was a dumb decision on my part. I replaced it with the HD DA 40. While the 40 is a superb lens that I enjoy, there are many times I wish I still had the FA 35 (it injects photos with pixie dust - not quite FA 31 Ltd pixie dust but pixie dust the neutral rendering HD DA 40 doesn't have). On your K-3 the AF should be very fast and accurate as it was on my K-5II.

You can also boost your cameras performance by eliminating the lag between AF and shutter release. Turn off the AF for shutter release half-press in your camera menu and use the AF button with your thumb while your forefinger normally activates the shutter release.
09-03-2016, 03:52 AM   #11
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For portraits and shallow DOF on a K3 I would suggest the Sigma 30 or 35, Sigma 50, DA50, DA*55, DA70, FA77, Sigma 85, DA*50-135, Sigma 50-150. Only the sigma 30, DA50, and DA70 fall in your price range. You would probably be able to get both the sig 30 EX and DA50 (or DA50 and DA70) used for under $500
09-03-2016, 04:32 AM   #12
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QuoteOriginally posted by rrstuff Quote
Here are some things I am thinking of, trying to keep things below $500, all used: - Canon 1D Mk ii or iii + 50mm F1.8 STM , or 50 F1.4 - Panasonic/Leica 25mm F1.4 - DA 55mm F1.4 (but AF might be troublesome?) - Canon 5D/1Ds Mk I + 50mm F1.8 STM or just be done with it all and get a sony A7 + Canon EF adapter + 50mm F1.8 (~$1300).
I really don't understand this. This sounds like such an odd mix. What equipment do you already have, exactly? It looks like you have a Pentax camera and a bunch of Canon lenses?
Anyway, shallow DoF is a gimmick and does not really give you much in the long term.

You can get something like K-S1 with DA 50mm f1.8, or Samyang 85mm f1.4 (super shallow DoF, you will learn to fear it). That is what I would recommend to someone without gear to buy if their main goal is shallow DoF. Full frame DSLRs will immediately cost much more, or you will be buying really old camera with significantly worse sensor than what is available today. I don't think sacrificing so many modern features and modern ISO performance is worth the slightly shallower DoF. Especially due to resolution differences - higher resolution will appear to make the DoF more shallow and the in-focus area more sharp, detailed. That is why I would avoid buying a Canon FF dinosaur. Not to mention its use, the shutter getting closer to its death, other damage the camera has accumulated over the years, incompatibility with modern SD cards, wifi, lack of video features, and so on
09-03-2016, 04:49 AM   #13
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QuoteOriginally posted by Na Horuk Quote
I really don't understand this. This sounds like such an odd mix. What equipment do you already have, exactly? It looks like you have a Pentax camera and a bunch of Canon lenses
I think right now the OP has the K-3 + DA50 f/1.8 + DA40 f/2.8 (not sure if XS or Limited), plus an Olympus m43 with 45mm f/1.8...

The Canon camera and lenses, or mirrorless cameras, are some of the options.
09-03-2016, 05:26 AM   #14
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QuoteOriginally posted by Saltwater Images Quote
I have had both the FA 50 f/1.4 and FA 35 f/2... The 50 was tack sharp across the entire frame at f/2 - I found it soft wide open.
The FA50 f/1.4 is certainly softer wide open than when it is stopped down, but in many situations I find it works just fine - especially portraiture. The attached three shots were taken just now with the FA50 at f/1.4, f/2 and f/2.8 respectively (with focus on the cat's right eye)...
Attached Images
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
View Picture EXIF
PENTAX K-3  Photo 
09-03-2016, 05:29 AM - 1 Like   #15
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QuoteOriginally posted by BigMackCam Quote
The FA50 f/1.4 is certainly softer wide open than when it is stopped down, but in many situations I find it works just fine - especially portraiture. The attached three shots were taken just now with the FA50 at f/1.4, f/2 and f/2.8 respectively (with focus on the cat's right eye)...
Remarkable... How did you Get the cat to cooperate? Mind control?
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