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03-08-2012, 09:46 AM   #31
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The crap.factor calculation is meaningful for experienced 35mm FF toggers transitioning to APS-C (frame size about the same as 135/HF, half-frame). For everyone else, it's not so meaningful, and even induces confusion. A lens does NOT stretch nor shrink when moved to another camera. The calculation ONLY affects FOV and DOF.

I'm old enough to appreciate the calculation. If I know what a Takumar 55mm @f/4 image looks like on my Spotmatic, I can expect about the same with a Mir-1 35/2.8 wide-open on my K20D. But I mostly use the same approach I did long ago when I'd shoot 135/HF, 135/FF, 6x6/MF and 9x12/LF on the same day: Learn what each lens does on a specific camera. Become intimately familiar with the FOVs of different focal lengths (FLs) on different frame sizes. Know the 'normal' FL for each format; extrapolate FOV vs FL from there. Half-normal is pretty wide, 2x-normal is for 1/2-body portraits, 3x-normal is for headshots, etc. Easy-peasy.

03-09-2012, 06:12 AM   #32
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I recently picked up a used F-50mm/1.7 - autofocus lens (in case you haven't sorted out the difference between DA, FAJ, FA, F, A, M, and K yet). It is useful for portraits in a large room, but in close quarters, like trying to catch my kids in the house the 35/2.4 would be better. A lot depends on the type of shooting you'll be doing and how fast you can autofocus a manual focus lens. I've picked up a few manual lenses, and they are great when I have time to compose a shot. But when I'm shooting "snapshots" at an event, the autofocus helps a lot. The 35/2.4 looks like a nice lens, but other than speed it doesn't gain you anything over the 18-55, which is a very capable lens except in low light situations. The 50-300 will give you a broad range of focal lengths, and in that respect would be a nice complement.

I'd suggest you also look the Buy and Sell section of this forum, so you can see what sort of used lenses are available. Buying from someone here will be a lot more reliable than through an auction site where it can be hit and miss. Browsing is also fun and cheap - until you actually start buying.
03-09-2012, 06:13 AM   #33
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QuoteOriginally posted by RioRico Quote
The crap.factor calculation
Was this an intentional typo?
03-09-2012, 08:13 AM   #34
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Thanks for sharing MSL.
I think I need some speed. My daughter is pretty fast

I'm with you about the AF lens. Though a manual-only lens oughta be fun and increase my dslr learning curve, based on my experience/needs I'd prefer an AF lens especially with the KXs AF C. I think I need every bit of help to best capture my kids.

Now if you say the 35/2.4 is better I want to add the I tend to have lighting/brightness issues here in my household and in general. Our house is not particularly bright as we use energy efficient bulbs and not a lot of them per room at that. I have ordered a flash unit for the kx which should make that a mild to non-issue. Now with summer coming I can see no problems even with my stock 18-55mm lens but suppose I do want that prime for those perfect shots. I did practically buy this camera to both have fun with this old hobby of mine and to get better pics of my kids.

About the 35/2.4 or the 50/1.4, which would fare better if lighting is an mild to moderate factor?

03-09-2012, 08:38 AM   #35
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QuoteOriginally posted by Iksobarg Quote
About the 35/2.4 or the 50/1.4, which would fare better if lighting is an mild to moderate factor?
First off, I'm comparing a 35/2.4 and a 50/1.7. Both are in the same price league. A 50/1.4 isn't. What may be better is to wait for the new DA 50/1.8 to come out and decide then. That lens should also have some impact on the prices of other moderately fast primes.
I don't like shooting flash. I find the built-in flash on the K-5 very harsh, and unless I'm some distance from my targets, they all get blinded. While it is trickier without it, the nice thing is that you can take multiple pictures and the targets don't know you are photographing them, so the poses stay natural. Add to that a burst mode, and you can get some really nice keepers, at the small expense of having to wade through a lot of pictures.

I'd also suggest you look at the best photos you've taken with the 18-55 and see what focal length you were using. Unless the bulk of them are at the 55 end, you may find a 50mm lens too big.

One other trick, especially with young kids who can play in a small space, or in repeated patterns (like running in circles) is to focus on a spot, and then wait until they are back in that position and shoot. There are a number of posts around on catch-in-focus that may be of interest.
03-09-2012, 08:45 AM   #36
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I'm visiting this thread atm.. https://www.pentaxforums.com/forums/pentax-slr-lens-discussion/129161-50mm-1-...5mm-2-4-a.html
03-09-2012, 09:51 AM   #37
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QuoteOriginally posted by MSL Quote
QuoteOriginally posted by RioRico:
The crap.factor calculation
Was this an intentional typo?
Back in the day when I was sometimes shooting multiple formats daily, 'crap.factor' and 'equivalent' were not in the language. We knew about FOV differences but marketers hadn't yet churned-out those terms. We see the result now: zillions of n00bs horribly confused, either thinking that lenses stretch or shrink on different cameras, or that their P&S and dSLR or MILC should deliver similar images at 'equivalent' focal lengths. Crap.

I can live with the German term format-faktor because it's a bit more indicative of reality. But when I see questions like "Do I tell the SR'bot 75mm when I mount a 50mm M42 lens?" or "Isn't this 300mm lens really 450mm on APS-C?" then I know that the crap.factor demon has struck again. Exorcise that demon! No more crap.factors! Down with crap!
03-16-2012, 08:04 PM   #38
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I will throw in my little bit of opinion.

I also bought the K-x with the dual DAL zoom lenses. They work awesome but I kept changing them very often and that can be stressful. At one time I was in a cruise boat off Cabo San Lucas trying to get it all and get the details. I kept changing both lenses but being in a rocking boat at the edge of it taking photographs so I was very stress by the idea of dropping any of my lenses not only in the deck but overboard.

Then I learned about the Tamron 18-250mm zoom that was later rebranded as Pentax and set myself out to get one, which I did right here in this forum with a fellow member that was selling a used one. It turned out to be a pristine example of it, the price was fair so I now cover the full length of my original lenses. I still have them and want to keep them but now I use solely the Tamron that has turned out give me soooo much flexibility in what I like to do; concentrate in my photos.

By the way, I do also own a 33 year old M lens, an f/1.4 50mm that has been with me since new. Hope this give you a different perspective to how to approach your next purchases. Enjoy.

03-16-2012, 11:14 PM   #39
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QuoteOriginally posted by trevinon Quote
Then I learned about the Tamron 18-250mm zoom that was later rebranded as Pentax and set myself out to get one, which I did right here in this forum with a fellow member that was selling a used one. It turned out to be a pristine example of it, the price was fair so I now cover the full length of my original lenses. I still have them and want to keep them but now I use solely the Tamron that has turned out give me soooo much flexibility in what I like to do; concentrate in my photos.
Exactly right. The DA18-250 is just the most flexible option for many situations. It's there when needed. I don't use a 18-55 plus 50-200 or 55-300 kit because I shoot a lot between 35-70mm and I hate swapping lenses at 50-55mm. So what if the 18-250's IQ isn't the ultra-best? The IQ of a missed shot is zero. (I'll confess to sometimes using a set of the DA18-55, F35-70, and Tamron 60-300 or FA100-300. But not often.

When I bought my first dSLR, the K20D, my original kit consisted of just the DA10-17 (the lens that drove me to Pentax), DA18-250 for general use, and FA50/1.4 for low light, action, and DOF control. With the addition of the Tamron 10-24 (and ~230 other lenses) those are still my most-used kit. The DA18-250 is my basic lens; all others are specialty items, if indispensable.
03-17-2012, 02:54 AM   #40
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Thanks for your recent posts guys. Very helpful as the wheels here are turning

New quiery:
anyone have any experiences with this lens and details about it?
Soligor MF C/D 4-5.6/60-300 mm Zoom+Macro MC
03-20-2012, 02:00 PM   #41
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well I did it...

I read a lot from many sources, including here of course and especially Stan's Pentax Photography <-the summary comments are indeed good.

So along with my stock 18-55mm AF lens I've gone and rounded out my Kx lens kit (for now).
Pentax-A SMC 50mm F2 (brand new in box) $30 (it's in the mail)
Pentax SMCP-FA 80-320 mm F/4.5-5.6 AF $85 (it's in the mail)

So far so good however I'm still needing to learn how to program and use the green button and it seem like soo many other things.

One thing I can't help but notice and wonder about is:
1. that my Kx results are better (than my compact cams) in lower light settings however not moving objects (not moving fast); I've tried to capture my daughter doing her horseback riding classes (just walking speed) in a large (not well lit) riding hall... all zoomed pics are pretty bad (anything that was moving is a horrible blur), wide angles tended to be better but still not accceptable. I've managed to get so-so good pics with the stock flash. One thing I'm certain I'm not using the EV value -/+ properly yet and of course there's some issue of my using the right fstop, iso and shutter speed.
However, most frustrating is that I used auto and action (daughter's riding hall) and results were still bad. For a bit I thought my Kx was suffering from some problem/calibration/whatnot. I've taken a step back and decided to be patient, re-read the manual and get the info. that's going to make a difference.

2. My other Kx pics, I'm getting good results of outdoors, well lit indoors, yes, but when I stop and think about how they compare to the pics from my Canon A1200 and Canon A630, well the Kx pics don't stand out immediately as superior. I reference it this way: if I had to do a blind test to select which pics were taken by which camera I do not think I could actually tell a difference, and that's not all true. Some of my Kx pics are downright soft when the settings were in the ballpark, auto or action in sunny setting. One thing I know is I'm still getting acquainted with my new friend and believe IQ will improve however right now I'm a little disappointed with IQ compared to my much cheaper cams.

All support and feedback is appreciated. \o/
03-21-2012, 10:05 AM   #42
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Hi Iksobarg:
I can relate to what you are sharing with us. You are right when saying you need to get better acquainted with your new "friend". I had the same issues with it at the beginning. If it serves you of anything, I started taking photographs with Auto but found that it provided with sub par results in low light or interiors. I switched to Tv and flash and things have gotten much better. That way you can set the speed to something that would freeze better the action, and the flash provides the right exposure.

Hope this helps.

Norberto
03-21-2012, 10:16 AM   #43
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QuoteOriginally posted by Iksobarg Quote
I read a lot from many sources, including here of course and especially Stan's Pentax Photography <-the summary comments are indeed good.

So along with my stock 18-55mm AF lens I've gone and rounded out my Kx lens kit (for now).
Pentax-A SMC 50mm F2 (brand new in box) $30 (it's in the mail)
Pentax SMCP-FA 80-320 mm F/4.5-5.6 AF $85 (it's in the mail)

So far so good however I'm still needing to learn how to program and use the green button and it seem like soo many other things.

One thing I can't help but notice and wonder about is:
1. that my Kx results are better (than my compact cams) in lower light settings however not moving objects (not moving fast); I've tried to capture my daughter doing her horseback riding classes (just walking speed) in a large (not well lit) riding hall... all zoomed pics are pretty bad (anything that was moving is a horrible blur), wide angles tended to be better but still not accceptable. I've managed to get so-so good pics with the stock flash. One thing I'm certain I'm not using the EV value -/+ properly yet and of course there's some issue of my using the right fstop, iso and shutter speed.
However, most frustrating is that I used auto and action (daughter's riding hall) and results were still bad. For a bit I thought my Kx was suffering from some problem/calibration/whatnot. I've taken a step back and decided to be patient, re-read the manual and get the info. that's going to make a difference.

2. My other Kx pics, I'm getting good results of outdoors, well lit indoors, yes, but when I stop and think about how they compare to the pics from my Canon A1200 and Canon A630, well the Kx pics don't stand out immediately as superior. I reference it this way: if I had to do a blind test to select which pics were taken by which camera I do not think I could actually tell a difference, and that's not all true. Some of my Kx pics are downright soft when the settings were in the ballpark, auto or action in sunny setting. One thing I know is I'm still getting acquainted with my new friend and believe IQ will improve however right now I'm a little disappointed with IQ compared to my much cheaper cams.

All support and feedback is appreciated. \o/
the above comments from trevinon are good. but there is more to it. unfortunately letting the camera make decisions for you is not the best method as the setting may well not match up with what you want.
The sad fact is many people find themselves underwhelmed by the results they get when moving from P&S to DSLR. there are a lot of reasons for this. one is P&S have enormous DOF even when wide open and shooting in dim light so odds are better of getting focus.

A good starting point would be to read the book below. I (and a lot of others here) recommend this book to newbies regularly. well written easy to grasp and it will improve your results for certain. Knowing how the triumvirate of iso/aperture/shutter interact makes a big difference

Understanding Exposure: How to Shoot Great Photographs with a Film Or Digital Camera: Amazon.ca: Bryan Peterson: Books

Like mentioned though you may want to set the kx auto iso to cover up to 1600 and use a off board flash in conjunction with the camera (ie not the built in one which is useless in a large area). Max shutter speed for flash is 180 or you will have other issues. the flash actually will freeze action for you provided it's not really fast action as it is on for far less than 1/180 second
03-21-2012, 05:08 PM   #44
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I agree with you eddie 1960. But still, using an off board is adding complexity to the formula in the initial stages of learning.

I used my K-x for a little over a year with only the built in flash with very good results. I typically work with ISO 1600 or 3200 without noticeable degradation, but then again I do not blow up my photos. I already bought a good out board flash but found by experience that now I need to learn how to use it in combination with my camera. I am back to the bottom of the experience curve with it.

I find myself using the off board flash as often as the built in one just out of convenience. The results so far are mixed until I am able to master the off board one.
11-01-2012, 07:34 AM   #45
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QuoteOriginally posted by eddie1960 Quote
the above comments from trevinon are good. but there is more to it. unfortunately letting the camera make decisions for you is not the best method as the setting may well not match up with what you want.
The sad fact is many people find themselves underwhelmed by the results they get when moving from P&S to DSLR. there are a lot of reasons for this. one is P&S have enormous DOF even when wide open and shooting in dim light so odds are better of getting focus.

A good starting point would be to read the book below. I (and a lot of others here) recommend this book to newbies regularly. well written easy to grasp and it will improve your results for certain. Knowing how the triumvirate of iso/aperture/shutter interact makes a big difference

Understanding Exposure: How to Shoot Great Photographs with a Film Or Digital Camera: Amazon.ca: Bryan Peterson: Books

Like mentioned though you may want to set the kx auto iso to cover up to 1600 and use a off board flash in conjunction with the camera (ie not the built in one which is useless in a large area). Max shutter speed for flash is 180 or you will have other issues. the flash actually will freeze action for you provided it's not really fast action as it is on for far less than 1/180 second

I got the book a few months ago... read it... good stuff!

I've read a lot of lens reviews in preparing to upgrade my kit.

I've also had about ~10months with my DA 35/2.4, Pentax-A 50/2, and FA 80-320/4.5.
I've now decided I need lower light performers and lenses that better capture my kids in action. So I recently purchased both Pentax-A 50mm F1.4 and an FA 50mm F1.4 and plan to let go of at least the DA 35 but am looking into either the 43 or 31 limited, the latter being prohibitively out of my price range

I recently read from a poster that such 1.4 Fstop lenses are not preferable to the smaller apertures such as F2.4 for out in the sun pics. True?

Last edited by Iksobarg; 11-01-2012 at 09:17 AM.
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