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01-04-2011, 04:10 AM   #16
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ok understood about the 300 end comments, so would I be better off not going past say 200mm if a tight crop is suspected to be required, and or would I be better off using a 50-200wr that I recently acquired? I know I will need to test the lenses but a start point would be
helpful.
Any thoughts on the -
In PS when the tool selected is the magnifing glass if I zoom in to 33% in PS on any image then the ruler size on screen matches a ruler held up to it.
Is this then actually viewing print size rather than the larger size shown by using the print size option button? If so what is the print size button display ment to represent?

01-04-2011, 04:33 AM   #17
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Alistair

your on the right track mate , IMO.

test you lenses, and see what you can get away with..some shots I just wont take if I need to crop in a lot, as I know the results will be piss poor...

I cant really answer the question about your lens choice..as I don't own any of them..youll have to experiment with em

cant help with PS too much either..as Im on a steep leaning curve meself there ...at least this mystery is solved for ya....best of luck ole son
01-04-2011, 04:41 AM   #18
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ok here are 3 images all the same speed shutter and iso at 300mm the 300 and at 200 and the 200 at 200 the focus point was the green fatball feed bags , all three hand held.
at 1:1 they all look dreadful but if I zoom to 33% on the 300 and 44% on the two
200mm shots which makes them all the same size there is little difference between the two 200 mm images but the 30mm is soft.

Last edited by adwb; 03-31-2012 at 07:01 AM.
01-04-2011, 05:09 AM   #19
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Alistair: First, I think you must mean ISO100, right? If these are really ISO1000 on a k10d - then I am amazed. I would get WAY more noise at high ISO on my k10d. I have a K7 now, but before than I never, ever went higher than ISO400.

Your 55-300mm is definitely a much better lens at 200mm than at 300mm. But sometimes you just need the extra reach, even at the expense of sharpness. My avatar photo was taken with my 55-300mm, and even if it is not top-notch sharp, it was a treat to get that close to a burrowing owl. For the price, DA 55-300mm is a good 300mm lens. For a higher price there are better 300mm lenses.

I think, possibly, your focus might be ever so slightly off of the feed balls? The black bar holding the balls looks slightly more in focus, but I could be wrong.

Finally: When you shoot in raw, you will benefit from treating your photos to a BIT of unsharp mask in post processing if you want your photos sharp. Not too big a radius, and not too much, but experiment a bit. In GIMP I use a radius of 2 or 1 depending how much I have cropped.

01-04-2011, 05:22 AM   #20
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QuoteOriginally posted by MetteHHH Quote
Alistair: First, I think you must mean ISO100, right? If these are really ISO1000 on a k10d - then I am amazed. I would get WAY more noise at high ISO on my k10d. I have a K7 now, but before than I never, ever went higher than ISO400..
sorry if I said at some point k10 that was the trees the fatballs is with a K-r and yes 1000iso.

.
QuoteQuote:
Your 55-300mm is definitely a much better lens at 200mm than at 300mm. But sometimes you just need the extra reach, even at the expense of sharpness. .
thats what I thought re the 300/200 quality. interesting that the 50 -200 looks the same at 200mm as the 55-300 at 200mm quality wise [not size].
QuoteQuote:
I think, possibly, your focus might be ever so slightly off of the feed balls? The black bar holding the balls looks slightly more in focus, but I could be wrong..
yes thats what I thought yet I am using centre spot focus and it was right on the green bags I wonder if I have a focus problem it's not the first time I have though the K-r was out a touch, the K10 does not suffer with it at all.
01-04-2011, 06:35 AM   #21
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With regards to the the crop of the trees (taken with the K10D, f/14, iso 1000, 300mm):
ISO 1000 will not allow the same sharpness as ISO 100, f/14 is probably outside the sweet spot (try f/8 or f/9.5), 300mm is not the strongest point of the DA55-300 (as mentioned before).

The bird feeder:
The 55-300 @ 200mm looks slightly better in my eyes than the 50-200WR @ 200mm as there seems to be oh so slightly more detail, but that's only in a direct compare. In real life I doubt I will be able to tell with which one it's taken.
01-04-2011, 06:37 AM   #22
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QuoteOriginally posted by Tommot1965 Quote
if you wanna crop in and have decent res at that FL..your gonna need a 60-250 DA*
How is the DA*60-250 going to help him at 300mm? The DA*300mm is the ticket--way sharper than the 55-300 (at a price, of course ;~)
01-04-2011, 07:01 AM   #23
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QuoteOriginally posted by adwb Quote
I am trying to work out whether I constantly have out of focus images or if I expect to much. I am trying to understand if you zoom in on a image or crop a section out which then zoom in at what point should what appeared to be in focus become distorted if that makes sense?
The discussion so far shows that there are many factors involved. The only practical way to determine if zoom with lens A is preferable to shoot with lens B then crop to lens A equivalence is to try it. The DA 50-200 @ 200 cropped to 300mm equivalent may be better than the DA 55-300 @ 300mm and it may not; maybe enlargement by cropping defeats any sharpness advantage over the 55-300, maybe not. Further, it depends on f-stop too.

One could predict the difference given sufficient MTF data, but sufficient data is usually not available.

The lens to be zoomed by cropping must be quite a bit better than the longer lens; for example, when you crop a 200mm image to be equivalent to a 300mm image, you've spread 2 pixels @ 200mm pixel over 3 pixels of the 300mm image... that means the 200mm lens must be 1.5X "better" than the 300mm lens.

Finally, any zoom by crop must be less than the ratio of display width in pixels to sensor width in pixels (usually quite a bit less).

Dave

Recalling your original question: " ...zoom in ...at what point should what appeared to be in focus become distorted if that makes sense?"; I believe a reasonable answer is any zoom by crop must be less than the ratio of display width in pixels to sensor width in pixels and usually substantially less depending on lens quality and f-stop.


Last edited by newarts; 01-04-2011 at 08:14 AM.
01-04-2011, 07:49 AM   #24
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QuoteOriginally posted by dadipentak Quote
How is the DA*60-250 going to help him at 300mm? The DA*300mm is the ticket--way sharper than the 55-300 (at a price, of course ;~)

I should have said near- enough FL.....mind you a 300mm...wont be much good at 55 mm either
01-04-2011, 08:04 AM   #25
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QuoteOriginally posted by Tommot1965 Quote
just had a look at the specs of that lens and the EXIF of your image...you are at 300mm, that's right up the weak end of the 555-300 as as far as MTF resolution tests are concerned..at the borders {where you tree is} the lens drops off quite a lot in resolution ..this would add to your blurred out crop a lot IMHO

after all said and done..the "as" captured image looks good.....if you wanna crop in and have decent res at that FL..your gonna need a 60-250 DA*
Or a good 300 prime. Unfortunately good and 300 and prime don't always gel with one's pocketbook (neither does the 60-250 unfortunately)
If you are going to shoot at 300 a lot I'd suggest hunting down a nice M series f4.0 as they are superb for their price and easily outperform the 55-300 at that length. the A series f4.0 is much the same lens but demands a big premium due to the easier use with the a function (damn crippled k mount)
01-04-2011, 08:20 AM   #26
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when all said and done..its about capturing the image in the frame as you want to see it..with minimal cropping ...if anyone expects to crop in much past 100 % in any lens, then your asking for the impossible if you still want a 100% sharp image..

if your in a position where the subject is minimal in the frame.. don't press the shutter..use your feet. and if that wont work. then today aint your lucky day.

having said all that..sometimes any image is better than no image...if its a one off opportunity.

for full frame sharpness border to border, you need to shell out larges Wads..if we could all get fantastic results with a $300 lens..why would we need to buy anything else ?
01-04-2011, 08:23 AM   #27
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Here's something I think true for perfect lenses:

Decreasing f-stop by a factor of X increases resolution by the same factor of X*. Therefore, decreasing f-stop by a particular factor allows enlargement by the same factor.

This is far from true for practical lenses at low f-stops (usually it is reversed) but might give guidance at higher f-stops.

Dave

* within the resolution capabilities of the sensor.

Last edited by newarts; 01-04-2011 at 08:44 AM.
01-04-2011, 08:33 AM   #28
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QuoteOriginally posted by Tommot1965 Quote
when all said and done..its about capturing the image in the frame as you want to see it..with minimal cropping ...if anyone expects to crop in much past 100 % in any lens, then your asking for the impossible if you still want a 100% sharp image..

if your in a position where the subject is minimal in the frame.. don't press the shutter..use your feet. and if that wont work. then today ain't your lucky day.
The nice thing about shooting trees (as in the OP) is that they don't spook as easily as birds* so zooming with your feet is a meaningful option.

* If you do spook them, you're really having a bad day! ;~)
01-04-2011, 08:44 AM   #29
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if you don't mind ugly (and probably broken) there are some good deals. I'd love to know what the hell happened to this one fine lens

PENTAX SMC 300MM F4.5 ED IF LENS 1:4.5 on eBay.ca (item 120663224974 end time 21-Jan-11 08:34:56 EST)
01-04-2011, 09:35 AM   #30
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Pentax smc 300mm f4.5 ed if lens 1:4.5

QuoteOriginally posted by eddie1960 Quote
if you don't mind ugly (and probably broken) there are some good deals. I'd love to know what the hell happened to this one fine lens

PENTAX SMC 300MM F4.5 ED IF LENS 1:4.5 on eBay.ca (item 120663224974 end time 21-Jan-11 08:34:56 EST)
That particular one is still available on eBay.
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