What ISO to USE?

[tylerfj24]

<p>I am debating on getting the canon 70-200 f/4 IS or the F/2.8 IS. I know you all have seen this a hundred times but I cant find a question like this so please read on.<br>

I am leaning toward getting the f/4 IS and I will be putting it on a Canon 50d. Now the 50D that I use does very well at highers ISOs and Im not afraid to shoot at them. My question is what ISO would I have to shoot at to get the same affect of a F/2.8? If I go into a gym to shoot a game and of course the F/4 wont work, what ISO would I need to be at to shoot around 1/500 of sec and get decent lighting in the pictures? I ask because if its not that High of an ISO then I can save alot of money buying the F/4 and the little I may use indoors it still can be done with acceptable results.</p>

[john_macpherson]

<p>EXAMPLE (because your lighting will be different - ie its location specific so asking for a definitive answer to your question will not get one) - 800 ISO with f4 = 400 ISO with f2.8. OR looking at it another way 1/125 sec with the f4 = 1/250 with the f2.8.</p>

<p>Dont post the same question in two forums or you'll find both posts get deleted.</p>

[alan_olander1664878205]

<p>From f/2.8 to f/4 is one stop. Each doubling of ISO is one stop. To use the same shutter speed you would need to double the ISO, e.g 100 to 200, 400 to 800, etc.</p>

[chris_cross1]

<p>I am a 50d owner as well but i opted for the 2.8 is version. Though you are right you will save a substantial amount of money, you need to decide what whether you will utilize that extra stop. If you are a frequent low light shooter (gyms, churches, indoors, weddings, etc..) you will find the extra stop to be very handy. IS is big too as this is a heavy lens and the shutter speeds normally required wont cut it in low light. My recommendation is 2.8 if you can afford it/need it for your purposes. Otherwise the f/4 will do fine if you bump up the iso a stop but if you are already shooting in higher iso's to freeze motion then the f4 will be more problematic.</p>

[JDMvW]

<p>This is also posted on the Canon forum (<a href="../canon-eos-digital-camera-forum/00UJSs?unified_p=1">link</a> )</p>

[hjoseph7]

<p>Choosing an ISO that will give you the same efffect as a f2.8 is kind of impossible since the ISO determines the resolution of an image. The resolution of an image is usually better at the lower ISO settings. For example, an image taken with an ISO of 100 will show more detail and/or resolution than one taken with an ISO of let's say 1600. A 1 stop difference allows twice as much light into the lens and onto the film, or digital sensor. This extra amount of light hitting the film, or digital sensor creates a better image. Although digital sensors have been getting better in the last few years, if you want to take fulll advantage of your cameras light capturing capabilities, a lower ISO is usually the best way to go. During the days o film if photographers wanted to capture super-sharp and super detailed image they would use film with ISO ratings of 64, 50 and even 25. These films were very slow, meaning that they were not as senstive to light as films with Higher ISO ratings, but the detail obtained with these films were amazing. The same thing goes for digital sensors. A lens with a maximum aperture of F4 is not that bad, especially if it comes with IS, but it will certainly not out perform a more expensive lens with a maximum lower aperture at low light levels. </p>

[mark_drutz]

<p>If you are shooting sports in a gym you are better off with an f/2.8. Most gyms are pretty dark and you need all the speed that you can get. If the Canon 70-200 f/2.8 IS is too expensive look for a good used one. You could also give up the IS because it doesn't help much when shooting sports. It allows you to shoot hand held at slower shutter speeds, but these slower shutter speeds can still cause motion blur.</p>

<p>While the Canon lenses are excellent lenses there are very good lenses that cost much less. The Sigma 70-200 f/2.8 HSM is a very good lens for under $800 new. I would look at that as well as the Canon w/o IS if the Canon IS is too expensive. keh.com is a good source of used gear.</p>

[William Michael]

<p ><strong><em>"My question is what ISO would I have to shoot at to get the same affect of a F/2.8? If I go into a gym to shoot a game and of course the F/4 wont work, what ISO would I need to be at to shoot around 1/500 of sec and get decent lighting in the pictures?"</em></strong></p>

<p > </p>

<p >If you need to use the F/4 lens wide open, you will need exactly double the ISO that you would have required if you used the F/2.8 lens wide open for the same shot.</p>

<p > </p>

<p >The point is: if you have an F/4 lens you will run out of ISO exactly one stop before the person who has an F/2.8 lens.</p>

<p > </p>

<p >The other point is: the lighting in some School Gymnasia, for certain sports, is not adequate enough to allow F/2.8 to attain adequate Shutter Speeds, even at ISO 3200.</p>

<p > <br>

WW</p>

[rona_frank]

<p>this could help:<br>

<a href="http://www.lbguides.com/concepts/ISO.html">http://www.lbguides.com/concepts/ISO.html</a><br>

enjoy,</p>

[tylerfj24]

<p>Thanks for all your answers, but Im not going to be shooting inside all the time, actually I hardly ever shoot indoors. Im just stuck on this one. I'm not sure if Ill need the 2.8 but I want to know how much it will effect me all around if I go with the f/4. Also, if I go with the f/2.8 NON IS how would that effect my everyday use, I mean how slow of a shutter speed usually has someone lugging a tripod around, I know if I shoot sports at high speeds I can handhold, but if Im walking around with the 2.8 will I have a bunch of blurry photos or is it ok for that? I have never owned a NON IS lens and it scares me a bit, especially with this much money involved. Also I do not have camera shops around here to go try things out. I guess another way to put it is, when will I wish I had an IS lens?</p>

[William Michael]

<p ><em><strong>"I guess another way to put it is, when will I wish I had an IS lens?"</strong></em></p>

<p > </p>

<p >For General Photography, yes, <strong><em>if you do not have IS then there will certainly be times when you wished you had it.</em></strong></p>

<p > </p>

<p >*** </p>

<p > </p>

<p ><em><strong>"Also, if I go with the f/2.8 NON IS how would that effect my everyday use, I mean how slow of a shutter speed usually has someone lugging a tripod around"</strong></em></p>

<p > </p>

<p >I own this lens. </p>

<p > </p>

<p >I mainly (read 90% of the time) use it for sports and of that 90% use, 50% of the time I am indoors. </p>

<p > </p>

<p >I am happy with my purchase. <em>I think there are very few people who would use a 70 to 200 the way I do.</em> </p>

<p > </p>

<p >I do not lug a tripod around often. I do use a monopod often. </p>

<p > </p>

<p >On an OK day and Hand Held, I can successfully pull about Tv = 1/100s with the 70 to 200 at 200mm. </p>

<p > </p>

<p >I have done 1/80s, I think that is my best effort. I state these figures confidently, as I continually practice my craft. I am fastidious about knowing and respecting "limits".</p>

<p > </p>

<p >Others' mileage varies in regard to how slow can they go - it is not a competition - it is just useful to know what one can do - and in either case a monopod is a very useful tool even if it is only to give the right arm a rest from carrying telephoto and the longer zoom lenses. </p>

<p > </p>

<p >*** </p>

<p > </p>

<p >As a summary, if you do not use your camera for sports, inside all that often - then you might consider the 70 to 200F/4IS USM and team it up with the EF85F/1.8. </p>

<p > </p>

<p >As I mentioned earlier sometimes F/2.8 is not fast enough for the lighting in School Gyms. My 85mm has saved my bacon on several occasions in this regard – and for School Plays and the like, when F/1.8 was required and was pushed to the limit, and where IS would not have been of very little use: <a href="../photodb/folder?folder_id=925231">http://www.photo.net/photodb/folder?folder_id=925231</a></p>

<p > </p>

<p > </p>

<p >WW</p>

<p > </p>

<p > </p>

 

[tylerfj24]

<p>Well Im stuck on F/4 IS and F/2.8 non IS. The way I see it is if there is a time when I drop down to the 1/100's or slower I can always use a tripod or monopod, and obviously IS has not always been around. Or I will not need the extra stop but I would like the IS? I was outside at a soccer game taking photos at 5.6 and when the shade came over me it just became a hastle to try and stop motion, I hated that. Honestly I can say that I do not think I will ever have either lens inside at a sporting event, however I will be outdoors at sporting events, but I wonder at what part of the day the F/4 will start to be a problem? But I am usually out taking photos of animals and nature most of the time, sometimes I catch myself at a game but its definitly not the reason for the lens. Either lens will do for ordinary shooting, but its at the 1/500's or more Im worried about? I cannot afford the 2.8 IS so its not an option.</p>

[William Michael]

<p >Well, apart from what I have already stated, I add, the other 50% of the time I use my 70 to 200USM is at (Field) Hockey and Football matches. </p>

<p > </p>

<p >I can say, yes I do use the range F/4 to F/2.8 often - usually because I wish to preserve the ISO from going higher than 1600, whist still holding the Tv to freeze the action - it is a trade off.</p>

<p > </p>

<p >*** </p>

<p > </p>

<p >You state this: <strong><em>"I was outside at a soccer game taking photos at 5.6 and when the shade came over me it just became a hastle to try and stop motion, I hated that."</em></strong><strong><em></em></strong></p>

<p > </p>

<p >and then ask<strong><em> "but I wonder at what part of the day the F/4 will start to be a problem?"</em></strong></p>

<p > </p>

<p >Well it is only you who can begin to bring definitive approximations to that answer . . .</p>

<p > </p>

<p >You need to ask: </p>

<p >. what ISO was I at, when that happened? - how much more ISO did I have?</p>

<p >. what was the time of day?</p>

<p >. will I be usually shooting at that time of day?</p>

<p >. will I shot during rain (i.e. when it is likely to be darker)?</p>

<p >. will the groundsmen turn on Floodlights if it gets dark during the day?</p>

<p >. what my location (latitude) - it gets darker, earlier the closer to the poles</p>

<p >. if I am pushed to the limit at F/4, will I be happy to drive my 50D to ISO6400 or even ISO12800 and maybe just do high contrasts B&W images?</p>

<p >. can I live with the noise at and above ISO3200</p>

<p > </p>

<p >I can happily write that I have always had at least one extra stop of ISO up my sleeve and I could have used F/4 for any football match or Hockey meet <em>when shooting during the day: </em>but instead of pulling that extra stop of ISO, I have chosen to open the aperture wider than F/4. </p>

<p > </p>

<p >That is one of the reasons I chose the fastest lens possible so I could have that choice . . . but that does not answer your questions and your circumstances - you only can answer that: and to do that you need to evaluate the answers to the questions I posed to you.</p>

<p > </p>

<p >WW </p>

<p > </p>

 

[tylerfj24]

<p>Thanks WW</p>