[tabz]

Hi Croc,

My K-5 has similar AF trouble with fast lens. The AF system was replaced comletely because K-5 produced 0.5m front focus at 5m distance by low light condition. Repaired AF system works like yours. I am very disappointed because of K-5 AF. My previous body, a K200's shutter is dead at 8000exp. I am a loyal Pentax user but there are limits....

[Snydly]

Croc, are you using a filter in front of your lens?

I am only asking because I had a lot of problems with blurry pictures on my A50mm f1.7 in broad daylight (manual focus, so I can't blame the camera :-( ), then I narrowed it down to me using a cheap filter in front of the lens, and bright light was bouncing between it and the lens causing the image to be smeared.

Having said that, I'm in the process of trying to figure out what's causing some of my blurry pictures. I bought Marumi filters, which through research found them to be above average, but I'm not convinced I don't have the same issue.

Are you certain it made a difference with/without the filters, and if so, what kind were you using.

And to the same extent I saw a thread here a few month's back where someone more or less proved that the pictures are sharper with the hood on than off... Maybe something else to think about.

Thanks...

[Christine Tham]

Are you certain it made a difference with/without the filters, and if so, what kind were you using.

Yep - I took photos of the same scene with and without various filters. The focus is unchanged between shots (manual focus).

The Marumi Waterproof filter caused the worst smearing - I guess the filter is only meant to be used when it's raining (to protect raindrops from the glass). The effect is particularly pronounced in brightly lit objects.

The SMC coated Kenko caused the least smear.

So now I'm shooting "nekkid" on all my lenses and loving it.

[Siegfried]

- Honey, time to go to bed!
- I can't! Somebody's wrong there!
- Where, honey?
- There, in the internet!

I don't think I'm ruining this thread now since I believe it went wrong somewhere at the first pages (with all the respect and regret of mine going to OP with his Asahi-Hoya photogear issues).

I'm in the same boat with philippe here, who jumped in and - for whatever reason - later jumped out. Can I please have some sample photos made with APC-sized sensor that show the necessity of using f1.4 or f2.0 aperture when stopping down to f2.8 or F3.5 will kill the conception? Or in other words: can I please see a sample photo shot at f3.5-4.5 that was ruined cause of the aperture set not to f1.4 or such? No brick walls, please.

Thanks,
Zig

[Eruditass]

- Honey, time to go to bed!
- I can't! Somebody's wrong there!
- Where, honey?
- There, in the internet!

I don't think I'm ruining this thread now since I believe it went wrong somewhere at the first pages (with all the respect and regret of mine going to OP with his Asahi-Hoya photogear issues).

I'm in the same boat with philippe here, who jumped in and - for whatever reason - later jumped out. Can I please have some sample photos made with APC-sized sensor that show the necessity of using f1.4 or f2.0 aperture when stopping down to f2.8 or F3.5 will kill the conception? Or in other words: can I please see a sample photo shot at f3.5-4.5 that was ruined cause of the aperture set not to f1.4 or such? No brick walls, please.

Thanks,
Zig

Any shot where creative shallow depth of field of a certain degree is desired...

[Christine Tham]

Can I please have some sample photos made with APC-sized sensor that show the necessity of using f1.4 or f2.0 aperture when stopping down to f2.8 or F3.5 will kill the conception?

I don't know if taking this photo at f2.8 would have ruined the effect, but I really like how on this photo only the girl's face is focused - her mother looking at her (and everyone else in the photo) is out of focus:


Taken on FA50 at f1.4 (not my lens, borrowed from another Pentaxian on the day)

[Christine Tham]

Another example, the camera is focused on the scarf of the woman on the right, but her friend on the left - inches away from her - is out of focus - taken on the A135mm at f2.8:


I'm sure it could be argued that creatively this is a bad photo - perhaps her friend should have been focused as well, but I personally really liked the way this shot came out.

The difference in focus between the two women are much more obvious when the picture is blown up, or printed on a larger surface.

[Siegfried]

Christine,
I do appreciate you took it and so can I go on with your samples?

1. First I'd like to put out a disclaimer or nota bene: the following words are going to be mostly about a taste that real gentlemen (and ladies, that I think goes for your case) do not lecture each other about.
2.1 The first shot with a mother and a child on a merry-go-round would probably turn out to be better should it be taken with longer lens (and so from a longer distance) and something about F3.5-4.5 (I'm referring mostly to the experience of mine who wears Tokina AT-X PRO 280 28-80/2.8 as the primary lens). Or - on the other hand - you could go wider if you mean to put the background further away (and in this case f2.4-3.2 may be of definite sense). Personally, I find that background to be harsh and disturbing, but that just a combination of particular lens performance + particular scene, you're probably aware that most lens do good at certain aperture, focal length (in case of zoom) and distances. I do understand that you were carrying a fixed-focal lens and you didn't have any time to swap it with anything else - you just took that picture with the equipment you were having by your hand right then.
2.2 The second moslem photo: yes, I think that it would be probably be better should both faces be within DOF - both faces make up the action in the photo, the left one isn't a part of the environment that can be put into blur. But moreover, the background looks... Well, it looks like the original shot was made on some green background and later you re-composed it with another shot where you took that background from. I would try taking that photo at F4.5-5.6 aperture.
3. That was my absolutely humble opinion, please refer to #1

Dudes, the very shallow DOF is just a photographic tool like HDR, zoom blur, b/w shooting, slow shutter panning and so forth. Surely it can be used (and must be used) "where creative shallow depth of field of a certain degree is desired" (C) by Eruditass - but from all of my background and experience (which both are probably too small and neglible since I just don't get all these basics that are obvious and straight-forward to the others who shoot a lot in the style mentioned) I very rarely see a scene where I do need to go below F3.5 aperture (when using something from mid-wide to mid-tele, e.g. from 35 to 105mm effective). My fastest lens is f1.8 and besides the test shots and the first week when I was exploring that new world of shallow DOF - I never ever went below f2.4; it isn't about the lack of contrast or sharpness that lens gives wide open, I just haven't met (yet? I'm not a youngster but I should to be some optimistic, we all should) a scene that forced my going that shallow.

Thanks for listening,
Zig

P.S.
Probably I'm just not-enough-creative.

[Christine Tham]

Hi Siegfried, thanks for your comments

Both shots were taken on the spur of the moment with the equipment at hand, and the aperture was also more or less by accident - just happens to be what the camera was set at from a previous shot.

However, the point is, I actually like the way they come out and I think the photos would have been less interesting if I had used a different lens or different aperture. Neither of them are processed and they have zero or minimal cropping.

First photo: arguably the mother and child should both be in focus, but I ended up liking just the child in focus, because the photo really is about her, how she is enjoying the ride. The mother is there to comfort her, and it is appropriate the mother is out of focus even though she takes a larger proportion of the frame. Harsh background? Yes, but that can easily be fixed through post processing. I wanted to show the photo exactly as the camera captured it.

Second photo: as I mentioned before, yes arguably both women should be in focus, but again I ended liking it the way it is. I was focusing on the head scarf and originally was going to crop the photo to show just the scarf, but decided the photo tells a different story uncropped. It could be interpreted as her friend commenting to her about the beauty of her scarf, and it is appropriate for her friend to be out of focus since the photo isn't about her - it's still about the scarf.

It's interesting you mentioned the background. This photo is straight out of the camera unprocessed and uncropped. I like the creamy overexposed background and if the photo had been taken at a higher f-stop it would probably have destroyed the effect.

I understand your point about shooting at higher DOF/higher f stops. I very seldom shoot below f4 and probably the majority of my photos are taken at f4-f8. Like you, I don't believe in shallow DOF just for the sake of it, and I agree that sometimes I see photos that could benefit from a deeper focus zone.

However, both of photos are taken during shoots where I was deliberately experimenting with the creative possibilities of shallow DOF, and I ended up liking them just the way they are. If I was submitting the first one for a photo contest, I may try softening the background but the second one I love the way it is and won't want to swap it even if I could.

But even if you or I shoot mainly at f4 and above, it's not really our place to lecture others on what they want to do with their cameras. If someone wants to take a photo such that only a single strand of hair is in focus, and their equipment is capable of it, then they have a right to complain if their equipment is not letting them do it (through a focusing fault or whatever - the original topic of this thread).

[Siegfried]

Christine,
there's a difference between 'a perfect' shot and 'well, it's ok, we can live with it'. And with all the respect to your taste, opinion and view (and point of view) I have to say that those two shots are not perfect to me. I also have to note that the original question was about some samples that show a ruined photo cause of f3.2-4.5 aperture used instead of sub-f2.0 or a perfect sub-f2.0 one that will be ruined (definitely and undoubtedly ruined, not just slightly changed off) if going stopped-down, and now we're in the talks whether a shallow DOF gives another scene rather then the captured one or not - that's quite another idea, isn't it?

I do agree with you that should you go one-stop-down the shots would be a bit different (and to be honest that's quite obvious and it's like to agree with newton's law or not - that's the pure physics, i.e. optics) and to my taste I'd like them being that different (and I respect, though do not agree, with other opinions saying that they look good this different).
Probably I'm rreading too much deep between the lines, but it appears like you're going to agree that there's a chance that those two shots would probably be better should you stop down although you also like them as is, aren't you?

Nevertheless, I'd like to get back to original questoin and I'm looking fwd to seeing some very good to perfect photographic images with heavily expressed or even exaggerative shallow DOF that would be ruined (i.e. quite NOT good, much worse then they're now wide-open) should they be taken at aperture minus two stops from the original one. I'm not kidding, I'm really eager to see those shots. Just in case somebody again decides to go the obvious way: I'm aware of google's existence and have been to many photographic online galleries.

I'm sure that later this will bring up the counter-question 'dude, why do ya think they all are selling - and we're buying - that fast glass' - I'm ready to take that ball, but only after my 1st request is complied, 'der order iz der order'.

Thanks,
Zig

P.S.
Christine,
whenever it gives any excuse to me for going hard on your shots provided - or doesn't - I have to report that most of my own ones fall into that very category: 'well... ok, I can live with it'. Some others go for 'well... after some urge they'll agree they look good'.

[kenyee]

More wide open examples:

Example (not mine) of shooting wide open:
Nayla Maulida #1 | Flickr - Photo Sharing!

Nearly wide open:
http://www.flickr.com/photos/22013974@N06/5673538851/in/pool-1319461@N21/

It's mainly to get rid of backgrounds you hate. You see this a lot w/ Canikon's 200/2 lenses too (there's a flickr group or two about it).
*smile* | Flickr - Photo Sharing!
sharpest lens alive | Flickr - Photo Sharing!
Happiness of SEM | Flickr - Photo Sharing!
@ Golden Hour | Flickr - Photo Sharing!

And FWIW, croc isn't alone in thinking narrow DOF focus is weak...Herb Chong on FM thinks so as well and I know he's extremely OCD about testing since he does gallery sized prints...

[Christine Tham]

Probably I'm rreading too much deep between the lines, but it appears like you're going to agree that there's a chance that those two shots would probably be better should you stop down although you also like them as is, aren't you?

No - I think I am saying I like the shots exactly the way they are and they are "perfect" for me. I appreciate that your point of view may be different.

Could they be even "better" had I stopped down? Possibly, but it's a moot point since the moment has passed.

But you asked for shots that would have been "ruined" if the aperture were different and I firmly believe I would not have even kept these shots if I had used a higher f stop.

I do a lot of aperture bracketing in situations where I am unsure and I seldom prefer the ones that are too shallow, but these two are exceptions.

The point I was trying make, which I wasn't sure you understood, was it's not really appropriate for us to impose our tastes on each other or on the OP. If there is a problem that needs fixing, then advice or opinion on creative style isn't going to help.

[Siegfried]

Christine,
You made it clear now. Thanks a lot for jumping in and please excuse me for going that hard on your work, I really appreciate your patience and control - I wish I could say the same for myself!

kenyee,
thank you for those links. If you do not mind let me go step by step.

1. I do agree on the 2nd link ('woodland carpet') that it's a gorgeous photo and that that concept (an alone flower with haze-like background) would be lost if stopping down. 2/3 of the same goes for the 5th shot ('happiness of SEM') though I'm not that sure that the same scene stopped down would be any worse. As for the others - I either do not rate them any high at all or find the scene being potentially much better should it be shot one-two stops down or do not trust the image a single bit (e.g. in a case of the last 'golden hour' photo - I do know the rendering of EF 200mm f/1.8 L USM and the way the hair of that girl came out makes me claiming it was heavily enhanced in post-processing; that greatly increases the changes that other parts of the photo were also 'enhanced' with some software methods - that's an unfair cheating and we here are talking about the optic performance).

2. Every engineering school (or photographic system in this particular case) has some strong and week points. I didn't pick up the Pentax because of that, but I'm still with it (and I'm not going to leave it any soon) cause of its optics. I take Pentax (d)SLR bodies to be just boxes where Pentax optics can be attached to and where it performs the best. Should I need the best AF performance I'd go with N brand.
Every tool has its pros and cons, flaws and strong points. A trammel from X brand can be precise within 0-120F temperature range while trammel from Z brand needs to be re-calibrated if going sub-10F or above 80F (you can put any values here and from any favourite temperature scale you're used to). Does it mean that the 1st one is better then the latter one? Nope, there can be other characteristics where Z brand shines (from just more contrast - and thus more ergonomic - scale to weather-sealed pouch). Does it mean that Z brand must be cheaper then X brand? Nope, see above.
I payed the full price for K-5 and I'm happy with it. I came to K-5 from ist DS which AF module struggles VERY BADLY when going from incandescent light to sunlight and vice versa. I did hope that that extra wavelength sensor in the latest K-5 Savox engine should make it better but I never hoped it makes it 100% perfect and precise. And with that dinosaur-like AF (as well as main sensor + other stuff and bits) performance on ist DS I managed to get some very good results. I mean to say not only I find them being good, but also they gained some credits from other people whose opinion I do listen to.
It doesn't hurt me much to slave to Pentax photo gear, really. It's quite ok for me to go LV + contrast AF or to go thru menu and adjust those AF settings if I know that conditions around have changed and the change value goes above wavelength sensor limits - and I do not take it for the reason to claim the price I paid for my K-5 to be unfair. But your (or croc's, or Herb's) mileage may vary.

So far I dug out two main flaws of K-5: the lack of 'delete all' function while playback (on ist DS you only have to twice press the wastebasket button) and a significant shutter lag in LV mode. But I think I'll manage to live with this and as you can read from the stuff above I still find the paid price for K-5 to be fair.

Thanks,
Zig

P.S.
As you can see it in my profile I'm a newbie in this chatie, sorry. What's the english for OCD?

[Eruditass]

...

Photography is a creative, subjective, and highly personal field. There is no point in telling people they don't need this or that with their shots.

So far I dug out two main flaws of K-5: the lack of 'delete all' function while playback

In playback, hit menu, hit up, there's your delete all.

I'd much enjoy a wastebasket x2 button to delete the current photo, or at least wastebasket enter, instead of pushing an arrow key.

[Ash]

So far I dug out two main flaws of K-5: the lack of 'delete all' function while playback (on ist DS you only have to twice press the wastebasket button) and a significant shutter lag in LV mode. But I think I'll manage to live with this and as you can read from the stuff above I still find the paid price for K-5 to be fair.

Thanks,
Zig

P.S.
As you can see it in my profile I'm a newbie in this chatie, sorry. What's the english for OCD?

There are indeed a few little niggles that I'm sure Pentax could solve with simple firmware updates - the LED AF-assist in external flash shooting is one, as well as improving low light front focusing accuracy. I'm hopeful they'll come to the party with some of these.

OCD is obsessive-compulsive disorder, an overused term merely to describe in everyday language someone who obsesses over detail, thrives on order and struggles with imperfection. Strictly speaking, an OCD-'sufferer' goes to the extent of having the obsessions and compulsions affect and take over their lives.