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10-26-2010, 06:57 AM   #1
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Focusing technique with fast manual lens

Hi, I have a *1stDL with a K-7 on the way. I purchased few years back a 50mm F1.7 A manual focus lens. I can set the lens to A and the aperture control on the camera sets the aperture on the lens.

To my eyes this is a sharper lens than the kit 18-55 55-200 I bought.

But I am puzzled on focusing this lens. Maybe the Dl doesn't have the best VF or maybe it is how the lens focuses/depth of field. I know for example that at F1.7 and F2.0 there will be shallow depth of field but if I focus on the center point in the VF and shoot, usually at those apertures that focus point is not what is in focus so I have very few sharp shots.

I have tried the catch? focus technique using the AF mode on camera and turning the focus ring until the camera says, yep in focus, then takes the shot on it's own. Not as helpful as I thought.

I even tried both manual and catch while shooting in the woods waterfalls and such and didn't get many keepers.

Do you have any tips?

Here are 2 recent shots that were keepers and 1 from the day I bought the lens.

Thanks.

Picasa Web Albums - Kevin - 50mm F1.7

10-26-2010, 07:17 AM   #2
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What has helped me with MF accuracy is getting the Katzeye focusing screen (a split prism/microprism). I'm still working on getting quicker at focusing manually. That just takes lots of practice.
10-26-2010, 07:25 AM   #3
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like dasuhu, I use split image focusing screens to get focusing accurate with MF lenses.

In your posted photos, you have posted your successes, but what about your failures.

Sorry for asking but you learn more from the failures. it might be useful to look at these with respect to technique.

Specifically look at doing some shots wwith trap focus or using the indicator, but think about how you focus, i.e. turning the focusing collar left to right or right to left , in pentax terms is this focusing from infinity to close focus or from close focus to infinity. then think about where your focus error is, i.e. ahead or behind of the desired focus point.

It may simply be that you are focusing too fast, and continuing past ideal focus when you press the shutter or when the focus trap finally lets the shutter fire.

Although I love my manyal lenses, I find when I am in a hurry, I don't spend the time to get focus as accurate as with AF. but when I have time I generally do better.
10-26-2010, 08:02 AM   #4
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Agreement with above. Use split-image screen, Catch-In-Focus aka Trap-Focus, the indicator. Refine your technique: slow down; focus in and out to converge on the focal point; breath control; practice practice practice.

Depending on situations, you can measure the distance to a point, focus there, and wait for a subject to arrive there (useful with C-I-F). For a moving target or if you tend to focus through a subject, set the Drive Mode to Continuous Shooting, so you have more chance of getting an in-focus shot. It's like focus bracketing. But mainly, just practice.

10-26-2010, 08:23 AM - 1 Like   #5
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A split image screen is not required for good focus

Try these focusing exercises. Yes they are boring. But they work. Practicing scales on a musical instrument are boring also but I don't know of a better way to get proficient on an instrument.
The exercises were developed by Godfrey who was/is a very helpful and frequent poster over at DPR. I don't know if he's still posting as I very rarely go over there any more. In any event, here is a link to those exercises, give yourself 2-3 hrs a week for several weeks practicing them and I'll guarantee you'll get better.
Re: Is a KatzEye required for those using manual focus?: Pentax SLR Talk Forum: Digital Photography Review

NaCl(like any craft, photography responds well to practice)H2O

Last edited by NaClH2O; 10-26-2010 at 08:24 AM. Reason: spelling ;(
10-26-2010, 08:45 AM   #6
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Thanks for the link to the exercises and suggesting I take the focus slow. Odd thing was, I used to use a Canon AE1 all the time with manual focus and got tons of stuff in focus most of the time. It did have the split screen so if there was a vertical line anywhere in the picture line it up and there it is though I didn't use it as much.

I did find the DL viewfinder is much smaller and less sharp compared to the old film AE1 viewfinder which was brighter and sharper so I think that adds to the difficulty.

So maybe it is a bit more practice and use my eyes, not the green focus indicator. I was focusing in the distance in the woods. Sounds like these techniques will help and a screen as a last resort. I am hoping the larger K-7 viewfinder will make it a bit easier as well.
10-26-2010, 09:04 AM   #7
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Ok, a split screen is more useful for MF. Fine. How do you change the screen that is already in the camera, say in a K-X for example?

Thanks.

10-26-2010, 09:06 AM   #8
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I started shooting digital with the pentax DS which has a penta prism. After the K100D came out I checked out the camera but the viewfinder was so poor with the penta mirror vf that I stayed with the DS. I'm sure you will find the vf in the K-7 MUCH brighter than the one in the DL.

NaCl(it is a remarkable improvement)H2O
10-26-2010, 09:08 AM   #9
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The katzeye screen comes with detailed instructions and a handy little tool for making the change. IIRC there is even a video out on the web about it.

NaCl(you pay more for the katz eye but most ppl think it is worth it)H2O
10-26-2010, 10:43 AM   #10
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I've been using MF for about 40 years, and I still use it on digital the majorty of the time, simply because I know where I want the focus centered and AF can't read my mind.
The link to MF practice is a good one and is very similar to what I've used for years. The only thing I would add is that when looking for the "pop," don't look at the scene, but one particular point, such as an animal's eye.
Once MF becomes second nature, you'll be surprised at how fast you can do it, and how many more keepers you will get as compared to AF. If AF whirrs directly to the focus point and locks, it is a little faster than my MF, but if the AF hunts once or takes a second or two to lock, I can beat it.
Developing a good MF technique will also make you better at AF, because you will train your eye to recognize the focal point it chooses. It all about where you look and how you concentrate.
Be sure first, however, that your diopter is set to your vision.
10-26-2010, 01:17 PM   #11
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QuoteOriginally posted by Ron Kruger Quote
Be sure first, however, that your diopter is set to your vision.
X2...:-)
10-28-2010, 04:18 PM   #12
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QuoteOriginally posted by Corvairfan Quote
I have tried the catch? focus technique using the AF mode on camera and turning the focus ring until the camera says, yep in focus, then takes the shot on it's own. Not as helpful as I thought.

I even tried both manual and catch while shooting in the woods waterfalls and such and didn't get many keepers.

Do you have any tips?

Picasa Web Albums - Kevin - 50mm F1.7
I would suggest not relying on the in-focus indicator because I use to do that with my manuals and found out that even the indicator has a little bit of give to it. You will notice that once the indicator light comes on you can continue to turn the focus ring ever so slightly and even that very tiny turn can throw the picture out of focus, especially with a large aperture.

So my tip would be, if possible, turn off the in-focus indicator light and solely rely on your eyes to determine when you are "in focus" (and of course the exercise mentioned earlier will help you get your eye trained better than the light)
10-28-2010, 05:11 PM   #13
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I did a bit more playing around based on all these tips and I do need to practice my techniques, ignore the focus indicator light and use my eyes. I was able to get the shots I wanted in testing by doing these things and I know it will help me more in the future.

Thank you.
10-28-2010, 08:47 PM   #14
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Corvairfan,
A big part of good MF technique is concentration, and I found the focus indicator a distraction, so I disabled it.
10-28-2010, 09:09 PM   #15
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QuoteOriginally posted by Corvairfan Quote
Hi, I have a *1stDL with a K-7 on the way. I purchased few years back a 50mm F1.7 A manual focus lens. I can set the lens to A and the aperture control on the camera sets the aperture on the lens.

To my eyes this is a sharper lens than the kit 18-55 55-200 I bought.

But I am puzzled on focusing this lens. Maybe the Dl doesn't have the best VF or maybe it is how the lens focuses/depth of field. I know for example that at F1.7 and F2.0 there will be shallow depth of field but if I focus on the center point in the VF and shoot, usually at those apertures that focus point is not what is in focus so I have very few sharp shots.

I have tried the catch? focus technique using the AF mode on camera and turning the focus ring until the camera says, yep in focus, then takes the shot on it's own. Not as helpful as I thought.

I even tried both manual and catch while shooting in the woods waterfalls and such and didn't get many keepers.

Do you have any tips?

Here are 2 recent shots that were keepers and 1 from the day I bought the lens.

Thanks.

Picasa Web Albums - Kevin - 50mm F1.7
When you have your K7, your entire world with that lens is going to change (for the better).

http://www.rolleiman.com/Photos/ForSale/Payfor85/TakenWith/K7JS6988m50f17sold.jpg

http://www.rolleiman.com/Photos/ForSale/Payfor85/TakenWith/K7JS6991m50f17sold.jpg

http://www.rolleiman.com/Photos/ForSale/Payfor85/TakenWith/K7JS6992m50f17sold.jpg

http://www.rolleiman.com/Photos/ForSale/Payfor85/TakenWith/K7JS6993m50f17sold.jpg

In each case, the center is the focal point. Since this is the M version of the lens I couldn't tell you what the apertures were. They were for whatever set proper exposure in M mode.

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