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Old Oct 21, 2009, 12:16 PM   #21
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nice post john.

i think it is quite well accepted that the 12mp sensor in the XSi is a very good sensor from Canon and renders fine detail as well as any.
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Old Oct 21, 2009, 12:17 PM   #22
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OK. Since we're in the world of DSLRs and not point-and-shoots, the criteria for making assessments on focus accuracy, sharpness etc goes up. In the point-and-shoot world it's OK to keep things simple - but that's simply not the case in DSLRs. Why? because a DSLR is NOT, repeat, NOT a point and shoot camera.

Let's take sharpness. Sharpness is a factor of several things. And, it's important that if you're going to look at sharpness in DSLRs you look past the point-and-shoot method. Because there are several factors involved.

First - image sensor of the camera. This affects overall image quality - there are a few exceptions but in reality almost every DSLR on the market today is capable of sharp photos in good conditions. There really is no advantage of one camera/system over the other for sharpness.

Second - image processing. Here's where differences start to emerge. Each system, and even within system there is variability on how default processing settings are applied. Some DSLRs default to little image sharpening and some default to more. It's SOFTWARE. And, most importantly, it's completey adjustable. So, when you only use the camera as a point-and-shoot you are often judging sharpness on what those default settings are. There are a number of photographers that although they prefer sharp images they prefer to apply sharpening in post processing rather than in camera. Others don't want to be bothered. So, bottom line - sharpning is adjustable.

JPEG Conversion - here is yet more processing and this isn't completely controllable. DSLRs have the capability to save in different file formats. A Raw file format has little to no processing applied (although some companies still apply SOME processing). When you choose JPEG realize that there is definintely processing done. ANd you don't have a lot of control over all of it. Yes you can tweak sharpness and saturation and such but there is still a base amount of processing that takes place. That processing differs from brand to brand and even camera to camera. When you read reviews you may see a camera has poor jpeg image quality but average or good RAW quality. What this tells you is the default processing applied during JPEG conversion doesn't produce the best results.

Lens: In the DSLR world, without a single doubt, the lens used has more to do with sharpness than anything else. PERIOD. The XSi with Canon 300mm 2.8 lens or 85mm 1.2 lens is going to produce sharper images than a 1d (pro camera) with 75-300mm lens. Additionally, when using zoom lenses - especially consumer level zooms - lenses tend to have the worst performance with wide open apertures. They also have worst performance at widest and longest zoom. So again, you have to be careful in judging sharpness the CAMERA is capable of - especially comparatively against other cameras.

Focus Accuracy - this plays a big part too. On one hand, it's the camera's responsibility to focus accurately. And there are certainly cameras that focus more accurately than others. And, even within a given camera it's possible a copy could have front/back focus issues. BUT, focus accuracy is also driven by factors outside the camera's control. First is how easy the subject is to focus on (i.e. is it a good contrasty subject in good lighting). Second, did the photographer do their job and get the focus point on a good contrast area of the subject. I've seen a number of supposed test shots by reviewers that were soft and I attribute a number of them to images that just weren't focused accurately. Can't say whether that's the camera or operator's fault. But guess what? No camera on the market takes perfectly focused shots every time. So you have to be careful about making a snap judgement on a single shot.

DOF - this is another big factor. DOF refers to how much in front of or behind the point of focus is in focus. More dof and there's more the appearance of sharpess. More DOF and focus innacuracies are more hidden. NOw, I mentioned before that most lenses are at their weakest when they are wide open (largest aperture) - that's also when that lens at that distance from subject will have the shallowest DOF. So, you have to be careful again on judging sharpness of a camera without taking into account DOF.

It's certainly useful to discuss sharpness, distortion, and other quality issues when discussing various kit lenses. But I would never recommend making decisions on a DSLR body's ability to produce sharp photos based on jpeg images using default settings and a handful of snapshots with a kit lens. Doing that, I would argue any DSLR on the market - if the lens used was comparable - would produce the same level of sharpness.
Thank you for that explanation, John G...it just goes to show that the lens is the thing, right? What makes it harder to discuss is the fact that not all lenses work on all cameras...so, it all gets so convoluted. You might love a particular lens for it's sharpness, range, and price--but alas, it only works on the Nikon camera. For example. You might not want the Nikon body for other reasons besides supposed sharpness. You might say, there might be an equivalent lens for the body you want--but I am finding that is not to be the case--or at least, it is priced a LOT higher ...If all lenses were available for all camera mounts, it wouldn't be so hard.
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Old Oct 21, 2009, 12:20 PM   #23
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yes, but in the amateur eyes, can we really tell the difference? All I know is I look at a photo and think it looks good--I would say "crisp." Things can be too sharp, for sure, if overprocessed...but that seems more rare to me than not sharp enough. My idea of "good" isn't always consistent with the reviewers who say "this image shows more detail and is obviously better than that one"...
My concern is exactly that. An amateur making a bad purchasing decision based on a photo or series of photos that are not understood (not saying an Oly 620 is a bad purchase btw).

I'm just wearing my Steve's hat ensuring a balanced view, also think we have slipped away from the SXi as we are now talking Oly
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Old Oct 21, 2009, 12:41 PM   #24
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Thank you for that explanation, John G...it just goes to show that the lens is the thing, right? .
Well, that's TCAV's signature. And to some extent it is true. BUT, if you re-read my post it's only PART of the story. But you have to be careful - again, in your other post in this thread you said "you look at a photo and you know it looks good" - there are SO many variables involved. ESPECIALLY when you look at only a couple of photos. The subject plays a part, the lighting plays a part and the photographer plays a HUGE part. For example, look at some of the Posted photos by Walter S on this forum - he uses an FZ28 camera - great digicam but as a tool not as good as a DSLR. But a number of his shots look infinitely more impressive than many shots taken by other photogs with DSLRs.

So photographer skill is a huge factor. I use a professional canon DSLR - the 1dmkIII. I don't do a lot of portrait shots but I do do some. And I'm using professional grade lenses to boot. I will see portrait shots from photographers using lower end DSLRs that blow away my best work. Why? Because they're better at it than I am. Is their camera body better? No. But they get better results because they know how to use it better. Of course I would contend a great photographer gets even better results with better gear. So, don't misunderstand me. The best shots with those entry level DSLRs are often with quality lenses. And they're still not as good a what portrait pros using my camera are capable of.

The KEY is to make sure you have the right tools for the job YOU want to do. No DSLR with kit lens on the market is capable of taking every type of shot. For some needs you need a different lens. FOr others you may need a flash. For others there is an advantage to one system over another. This is why it's so important for the individual 'what camera should I buy' posts in this forum - everyone's needs are different.
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Old Oct 21, 2009, 12:51 PM   #25
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Well, that's TCAV's signature. And to some extent it is true. BUT, if you re-read my post it's only PART of the story. But you have to be careful - again, in your other post in this thread you said "you look at a photo and you know it looks good" - there are SO many variables involved. ESPECIALLY when you look at only a couple of photos. The subject plays a part, the lighting plays a part and the photographer plays a HUGE part. For example, look at some of the Posted photos by Walter S on this forum - he uses an FZ28 camera - great digicam but as a tool not as good as a DSLR. But a number of his shots look infinitely more impressive than many shots taken by other photogs with DSLRs.

So photographer skill is a huge factor. I use a professional canon DSLR - the 1dmkIII. I don't do a lot of portrait shots but I do do some. And I'm using professional grade lenses to boot. I will see portrait shots from photographers using lower end DSLRs that blow away my best work. Why? Because they're better at it than I am. Is their camera body better? No. But they get better results because they know how to use it better. Of course I would contend a great photographer gets even better results with better gear. So, don't misunderstand me. The best shots with those entry level DSLRs are often with quality lenses. And they're still not as good a what portrait pros using my camera are capable of.

The KEY is to make sure you have the right tools for the job YOU want to do. No DSLR with kit lens on the market is capable of taking every type of shot. For some needs you need a different lens. FOr others you may need a flash. For others there is an advantage to one system over another. This is why it's so important for the individual 'what camera should I buy' posts in this forum - everyone's needs are different.
I was just saying that because your post seemed to imply that all current dSLR bodies would have sharp images with a good lens--I was just saying it is all so complicated! But I think the point of comparing apples to apples is a good one...a few sample photos isn't a good representation. Herein lies the problem--it seems like a trial with the camera is the only way around that.
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Old Oct 21, 2009, 1:05 PM   #26
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I was just saying that because your post seemed to imply that all current dSLR bodies would have sharp images with a good lens--I was just saying it is all so complicated!
YOu are 100% correct. Taking a knowledgable look at DSLR gear evaluation IS complicated. And I think a number of people moving up to DSLRs from digicams are misinformed becausse they want to think of a DSLR like a magic point-and-shoot. But DSLRs are systems. And, like any other complicated system, when you start to generalize and over-simplify you introduce more innacuracies and false assumptions.

Really - the professional reviews online are a great starting point for a DSLR. They do a better job doing cotrolled tests than most individuals on the web are going to do. So that's one part of it. Next part is finding advice from people that shoot what you want to shoot. If you really want to do a lot of family parties - you want advice from people that take photos at family parties. Remember no single camera/lens can do everything. So don't judge a camera's ability at family parties from a portrait shot or from a sports shot. When it comes to 'what camera do I buy' you don't need to know everything - you just need to know what camera/lens/flash/accessories are going to meet your specific needs. And the best way to figure that out is a combination of reading professional reviews AND advice from people that shoot what you want to shoot.

If you drive a buying decision off of your needs FIRST rather than looking at every DSLR on the market, the problem is easier to solve.
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Old Oct 21, 2009, 1:12 PM   #27
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a few sample photos isn't a good representation. Herein lies the problem--it seems like a trial with the camera is the only way around that.
Not true. What you want to do is see NUMEROUS samples - preferably from various people. Look, any DSLR owner that is active in photography forums is taking lots and lots of photos. Most of those photographers are sharing those photos with families/friends/clients and thus they're in flickr, smugmug, pbase or other online hosting site. So, it's a matter of asking to see GALLERIES. And here-in is where it's important to find people that shoot what you want to shoot.

For example, let's say I want to buy a Canon XSi for family functions and maybe some wildlife shooting. I'm goiing to search forums for those keywords and see what is posted. Hopefully I stuble across good discussions. Hopefully a couple photos. NOW, when I see photos I like I make a post or send a PM to that person asking for more photos. That has worked for me. Same thing when it's time to buy a lens - search for the lens AND type of photography in the same post in multiple forums. If people don't have photos I tend to discard their opinions. At the DSLR level if you're not proud enough of your shots to let others view them you shouldn't be giving people advice on how to shoot or what to buy.
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Old Oct 21, 2009, 4:23 PM   #28
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Not true. What you want to do is see NUMEROUS samples - preferably from various people. Look, any DSLR owner that is active in photography forums is taking lots and lots of photos. Most of those photographers are sharing those photos with families/friends/clients and thus they're in flickr, smugmug, pbase or other online hosting site. So, it's a matter of asking to see GALLERIES. And here-in is where it's important to find people that shoot what you want to shoot.

For example, let's say I want to buy a Canon XSi for family functions and maybe some wildlife shooting. I'm goiing to search forums for those keywords and see what is posted. Hopefully I stuble across good discussions. Hopefully a couple photos. NOW, when I see photos I like I make a post or send a PM to that person asking for more photos. That has worked for me. Same thing when it's time to buy a lens - search for the lens AND type of photography in the same post in multiple forums. If people don't have photos I tend to discard their opinions. At the DSLR level if you're not proud enough of your shots to let others view them you shouldn't be giving people advice on how to shoot or what to buy.
you must spend a lot of time on the computer! Just keeping up with this one forum has taken a lot of my time, much less googling forums that may or may not have photos that I'm looking for in them It has been helpful to see the photos here, but so far I haven't found any galleries that have use "lesser" equipment to take gymnastics photos.
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Old Oct 21, 2009, 8:22 PM   #29
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but so far I haven't found any galleries that have use "lesser" equipment to take gymnastics photos.
maybe that, in and of itself, is information worth knowing.
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Old Oct 21, 2009, 10:20 PM   #30
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I think it's time to replace my monitor. The landscape images look far from sharp and the second one in particular has lost a lot of detail and definition. Not very encouraging at all for those contemplating buying the camera. So, let's hope the problem is indeed with my monitor.

My question is, how come you used the Tamron lens instead of the kit lens, which apparently is a very decent lens?
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