robatkinson

Just came back to PN after a long time away to find that it is pretty much unusable at the moment... not such a great (second) first impression..

<p>I guess I should have clarified that I was referring to speedlites. Monolights generally have much longer durations as you have seen.</p>

<p>As stated above, you are essentially correct in that if the flash duration lasts for say 1/200 of a second then it will expose the whole image without any dark banding. However this length of flash duration only occurs when the flash is in FP mode (aka high speed sync).</p>

<p>If the flash is in normal modes then the flash duration is anywhere around 1/2000 - 1/4000 of a second, so if the shutter speed is set to anything above the flash sync speed (most commonly 1/250) then you will get a dark band along one side of the image.</p>

<p>Now if they could produce a program that didn't need the 'before' photo.. That would be cool.</p>

<p>Lowepro flipside 400 seems to fit the bill.. Its secure, could hold all the stuff you mention, is well made and you can get stuff out without putting it down if you do the waist strap up and then spin the bag around to you front.</p>

<p>I have the 300 because I have less lenses to hold to hold (7D, sigma 50mm 1.4, 17-50mm OS HSM, canon g12, memory card case, rocket blower etc) and it works wonderfully.</p>

<blockquote>

<p>They should not be confused with real life, nor expected to mimic real life</p>

</blockquote>

<p>I believe he is mainly concerned with replicating the size of real life and not the look. In which case I would suggest that you use a Macro lens. Although not all macro lenses are created equal and not all macro lenses will be able to acheive the same amount of magnification. A lenses with 1:1 magnification will be able to focus closely enough to cover the sensor with an object the same size as the sensor. For example on an asp-c sensor a 1:1 macro lens could create an image of an approx 2cm wide coin where the coin covered almost all of the picture. (Basically the size of the object in the image on the sensor is the same as the size of the object in real life).</p>

<p>On the other hand, some macro lenses can only acheive 2:1 (or maybe it 1:2, not entirely whether the image or the object comes first). This means that with the same coin they can create an image where the coin covers half of the picture.</p>

<p>Many, many photography competitions have clauses that give almost full rights to do whatever they want with the photograph over to the people running the competition as a condition of photo submission. There is no way to know whether this competition was one such, but if it was then he was most likely fully within his rights.</p>

<p>It also sounds like this comes under the fair use policy anyway..</p>

The B+W multi coated UV filter and the HOYA HD UV filter are both very good filters for quite reasonable prices.

<p>Thanks for the reply Jamie, but I am confident that once I get a good copy of the 50mm it won't break on me.. And besides I have a three year replacement warranty on it, so I dont really mind if it gets busted. I'm not a pro photog so its not going to cost me a job or anything if it stops working down the line..</p>

<p>The assurances on the body are good though. And I'm not seeing a bit of a trend with out of the box issues with the lens. I can just keep exchanging and testing the 50mm until I get a good one. The shop is only down the road so I could keep exchanging it everyday if I wanted to.. I think for the mean time I'll just get another one to test out, the solid built, sharpness, 77mm filter size etc. of the sigma are too nice to pass up easily.</p>

Thanks for the responses. I only took

the first copy of the prime back to

exchange it for another copy a few

days ago so I can just take it back to

the shop... Don't have to deal with

warranty or anything yet. I definitely

haven't dropped or do anything to hurt

the 50mm 1.4, haven't dropped the

zoom either but I dont have to much of

a problem with the focus on that as I

can adjust that to what I want with ma..

 

The prime(s) both the one I have now

and the one I returned both front

focussed so bad that +20 ma doesn't

come close to correcting them. The

one I have now would need +30 or 35

I'm guessing and the one I had before

was just off the scale. So obviously I

will have to return the one I have atm.

The fact that they are both so so badly

front focussing just had me wondering

if there is something messed with my

body?

 

I don't have any canon lenses to put on

and test so I guess I will have to just

keep taking the primes back and see if

I can get one the focusses well or is at

least in the range of MA correction.

And if I go through like five copies of

the sigma prime and still haven't got

one that works I'll assume there is

something wrong with the body's

focussing and send it in for repair?

 

Thoughts?

<p>I would appreciate some advice on some focussing issues that I am having.</p>

<p>I have a 7D body that is about 5 months old and recently bought a sigma 50mm f1.4 for it. I brought the lens home and tested out the AF seeing as the lens is pretty renowned for focus problems and I found that it pretty massively front focussed. So I took it back and exchanged it for another one which I tested just recently and it too front focussed pretty badly (about 4 inches in front of the test sheet which was about 8-10 feet away, although the first one was more like a foot). So, thinking that my camera body could possibly be calibrated a bit funny I test out my sigma 17-50 EX OS HSM and found that at 17mm it front focussed by about 4 inches and at 50mm it was pretty dead on over the same 10 foot(ish) test length.</p>

<p>So, question 1) is it normal for a zooms focus to vary that much over the focal length?</p>

<p>Question 2) Could my body possibly be calibrated wrong and front focussing the lenses? (I don't have another body to try them on so I'm a bit stuck in that regard..) If not I can just keep on exchanging the 50mm 1.4 until I get one I like..</p>

<p>And finally I did all my focus testing on a sturdy tripod at iso 200, shutter speed approx 125, f/2 (or 2.8 for the zoom) with <a href="../learn/focustest/">Bob Atkin's test scale</a>, so I don't think there is anything wrong with my test results. I repeated them several times.</p>

<p>Thanks for reading and any advice/opinions.</p>

<p>I think matt has it all if you add price and image sharpness and contrast to his list..</p>

<p>Im 20, so I think I really have a while to go (in a number of aspects) before I catch up to some of you guys.</p>

<p>Nathan, we definitely need to get out there up into the mountains etc. before it gets to hard! :)</p>

<p>I recnetly bought one and it front focussed massively. Im talking 30cm when focusing on something 2.5m away. I exchanged it for another one yesterday and it too front focuses pretty badly so that I can not fix it with the micro adjust on my 7D.</p>

<p>I have used them in manual focus and they are extremely sharp. The construction quality is really solid and the bokeh looks great so I guess I will just keep exchanging until I get a good one... (QC is the only downside of this lens I guess..)</p>

<p>For a DIY solution...</p>

<p>bolt two sturdy L brackets to the wall on either side of the background at the height you wish the top of the back ground to be. Buy a length of steel pipe to rest between them. You can get a sliding clamp on the pipe at each end of the background roll to push in and stop it unravelling more. gaffer tape the ends of the pipe to the L brackets to hold it in place and keep it easily removable.</p>

<p>If they are just snapshots then you aren't really going to be viewing them at 100%.. you may as well resize them down to smaller jpegs and then if someone blows it up it will get so pixelated that no one will be able to see the freckles/ blackheads etc.</p>

<p>Alternatively if you a going to print the photo to a size where things like that can actually be seen you would be doing yourself and your photos a big disfavour by not post processing them, at which point you could remove things like that or lower the overall image sharpness if that is what you really wanted.</p>

<p>In the professional world that is a non issue because almost every single image is post processed for the required level of sharpness in the various aspects of the photo (among other adjustments).</p>

<p>Finally, if you are shooting JPEG out of the camera you can lower the in-camera sharpening which may bring the photo more to you or your friend's tastes for portraits.</p>

<p>I find your response particularly amusing Ariel as I agree with its sentiments, although I can see why Lex feels the way he does given his career history.</p>

<p>Just echoing the thoughts above that this shouldn't be that dangerous but if it were me I would probably do the flaming one on a stand just in case and photoshop it over a non flaming one in the actual picture.</p>

<p>As always, if you use common sense (have something to put out flames, dont do it with anything flamable around..) then you should be fine. Besides a little bit of danger (real or perceived) makes every more fun anyway. ;)</p>

<blockquote>

<p>The <em>Nissin Di-466, Nissin Di-622</em> (Canon version, and Nikon version produced before February 2010), <em><strong>Sunpak PF30X</strong>, Sunpak PZ42x,</em> and <em>Sigma EF-500/530/610 DG ST</em> (Canon version) will not trigger when placed in a plain (two-contact) hot shoe as used by plain optical and radio triggers, and pc-to-hot shoe adaptors. These dedicated flashes need to have a signal on the additional (system-specific) pins found on dedicated flash units to trigger.</p>

</blockquote>

<p>The above is from dpanswers.com and would seem to indicate that you cannot you it with a wireless transmitter..</p>

<p>From what I can tell the flash was reverse engineered to communicate with older canon camera models and when canon made the 7d they changed something in the camera-flash comms protocol such that this flash cannot communicate with the camera. You could put it on a cold shoe and trigger it as a slave from the 7D's pop-up flash if [your flash] has that capability?</p>

<p>I believe he is saying that the sigma is sharper in the corners ('not soft') isn't really particularly meaningful unless you have something to compare it to..</p>

<p>I have to add that were I buying this lens corner sharpness would not be a primary concern. When you buy a 1.4 over a 1.8 you get it to shoot wide open at which point anything in the corners has been obliterated into cream. Or maybe you will shoot some portraits at f8 to f11 at which point the difference between each of the lenses in corner sharpness is much of a muchness.</p>

<p>Thank you very much to josh/photo.net! and to patrick for starting this all up. :)</p>

<p><a href="009vhb">http://www.photo.net/nikon-camera-forum/009vhb</a></p>

<p>I think that page should give you just about all the information you need...</p>

<p>Basically the 1.4 has a bit less flare, a tiny bit sharper, better bokeh, obviously is faster and a bit better build.</p>

<p>Negatives are the (much) higher price, added weight and size and a larger filter (although this being a bad thing depends on your situation).</p>

<p>ilia, please post a link to the photo rather that the photo itself if you would like more answers.</p>

<p>It can fire continuously but only for a certain number of bursts and at lower than maximum power so you would do well to have more than one flash in that case.</p>

<p>Regarding the auto focus, normally when you are flicking through the various focus point modes (ie. zone, single point etc) you can't see spot af or af point expansion. They dont give you the option to use those. So you go into one of the custom functions on the camera menu (the one that is called autofocus/drive I think) and 'enable' af point expansion and spot af. Then when you press the af point button and then the m-fn button repeatedly to cycle through af modes you will be able to see the af point expansion mode come up. It basically uses a single point which you can select to try and af, but if it cannot af with that point it tries to use the points immediately next to it. So it gives you a sort of safety cushion..</p>

<p>Also I would not set the in camera noise reduction so high. It isn't quite as good as doing it yourself in posts in most circumstances and it will reduce your FPS substantially when set that high and combined with low light.</p>

<p>Personally, I would set the camera to af point expansion one point or two above the middle in vertical orientation so that you are generally focussing around players chest/face. This can be activated via the custom function and the put into use by pressing the button top right on the back of the camera and then the little m-fn button to cycle through the various focus point modes. Read the manual for more info.</p>

<p>I would set af to the back af-on button so that you can stop the camera focussing when the referee or another player comes in front of the one you are shooting and continue to shoot with focus maintained on the right player.</p>

<p>I would also continue using AI Servo as you are doing and high speed contiuous shooting. A speedlight would definitely help (so long as you are allowed to use one.. many gyms ban them because they annoy/distract players). The roof is probably to high to bouce the flash although you may be able to bounce it off a white wall behind you if you are on the baseline and the players are close to you. Otherwise just diffuse the flash with a cover of some sort and shoot away. Keep in mind that using a flash would also allow you to get a bit more DOF with f/8 or so which would make focussing A LOT easier than on moving subjects with f/1.8.</p>

<p>Alternatively if you end up with a speedlight or two you could install them around the end of the court at one end either on stands or taped to a wall etc and trigger them wirelessly to allow you a bit more flexibility in using the 70-200 and to get some different lighting. How about you go there before hand and try it all out to see what looks the best?</p>