5d images not pin sharp?

[jaimesommers]

Hi,

Apologies I didn't give all the info.

I took both camera and lens to two different shops and they tried it on a 5d mk 2, also tried it on my 300d and they all were of the opinion it was awful.

I have tried sharpenig, but then to get the image at a sharp enough quality, it has that 'oversharpened' look.

I also want to purchase another lens and was looking at the 24 - 105 F4 instead of the 24-70, and the 70-200, but this has put me right off Canon lenses.

[Cathus]

well it sounds like you got a dud. In all the millions of lenses sold there are bound to be a few, you're just as likely to buy a dud different make as another from Canon, i.e. not very likely but there are a few about. But if it's put you off, I'm sure there are plenty of other possibilities.

I've had good Sigma lenses in the past 10-20, 18-50, 50-500 but currently shoot mostly Canon L.

(I've never had dud lens BTW, Canon, Sigma or Tamron)

[OldBoy]

Originally Posted by jaimesommers

Hi,

Apologies I didn't give all the info.

I took both camera and lens to two different shops and they tried it on a 5d mk 2, also tried it on my 300d and they all were of the opinion it was awful.

I have tried sharpenig, but then to get the image at a sharp enough quality, it has that 'oversharpened' look.

I also want to purchase another lens and was looking at the 24 - 105 F4 instead of the 24-70, and the 70-200, but this has put me right off Canon lenses.

Sorry you had trouble with this lens.

You shouldn't need to sharpen to get a pin sharp image. Just checked on WareHouse Express and one reviewer has said it isn't sharp but nine others say it is. This suggests there may be a few faulty ones around, and I think you were unlucky.

[KeithT]

I hear where you are coming from, but to be honest with you the 24-70 2.8 is one of the sharpest short zooms Canon produce. Firstly, if you want pin sharp images edge to edge you need to understand how to use this lens. Whilst the 5d is a superb image making machine it can have it's draw backs if it isn't set up right and I suggest you follow Jim Doty's advice about menu settings here: http://jimdoty.com/Digital/5d_menu_s..._settings.html I used his settings for nearly five years with my 5d and never had a moments trouble.

Lenses on full frame will show up every anomaly. Focussing correctly to achieve pin sharp stuff starts with using the optimum aperture for nearly all your work flow unless you need to change it for effects. The optimum working aperture for the 24-70 2.8L is 5.6.

Sharpening: you need to get into a routine that will benefit your sharpening and not destroy by pixilation.

For some years now I have been using the Lab Colour method and you can find a good tutorial on how to do this here: http://photo.net/learn/digital-photo...-in-lab-color/

In thirty years of photography I have noticed that much of the problems associated with focus is down to user error. Don't dismiss this as you will end up being dissillusioned with gear that requires some learning about and handling experience. I hope you are satisfied in your quest for perfection, though I doubt you will be.

I have just sold the 24-105 which I used for a good few years. That lens will give you the same problems if you don't shoot at optimum - f8. I own the 70-200 f4 L which is stonkingly sharp and worth every penny. The other lens I own is the 17-40, also sharp and massively wide on full frame.

[jaimesommers]

Hi,

Thank you so much everyone for your advice, I really appreciate it!

A couple of questions, if I shoot at 5.6 what is the point of having a 2.8 lens? Does it still let more light in generally?

In the lens forum, this has been recommended as an alternative : Tamron SP AF28-75 F2.8 Di Can A09 Lens
but at £400 I don't understand why it is so mych cheaper?

Views very much appreciated!
Cheers
Jaime

Warehouse Express are refunding the lens cost now.

[Cathus]

well if you're going to shoot at f5.6 all the time, then you could say no point at all really. The amount of light let in is a factor of the focal length of the lens , the aperture and shutter speed.

The aperture is a ratio based on the focal length of the lens, it can get quite complicated explaining it and I'm not technically-minded enough to bother much with these things, I'm sure someone else can explain it if you're interested.

You should be bothered about apertures when considering the aesthetic quality of your shot in relation to depth of field, 2.8 will show less depth of field than 5.6 but will allow you to shoot at a faster shutter speed, so it depends on whether shutter speed or aperture is more important in the circucmstances of the individual shot you are about to take. And this dictates whether 5.6 or any other aperture is more important to you than another aperture.

[KeithT]

Why shoot 5.6 with your lens? You said you were after pin sharp images and 5.6 being your optimum setting will deliver this more consistently than any of the other settings. If you shoot wide open you need to be aware of narrow dof and how easy it is to get images out of focus at the point of focus unless you are well practiced at doing it. The point of having fast lenses is to give you a brighter viewfinder in dark conditions. You can shoot at whatever aperture you want, but beyond 5.6 diffraction will begin to slowly appear, so not always best for pin sharp images. My suggestions would be to use centre point focus so that your subject is always pin sharp. Let the rest of the frame take care of itself.

[wave01]

Ditto above i always use the centre spot to focus and then recompose the frame

[jaimesommers]

Hi,

I thought I would update you as to how i'm getting on! I went to LCE in Lincoln and explained the problems i had been having and asked about the Sigma and Tamron lenses (they didn't have either of them in). They let me play with another lens on my camera and it was much better. They had a spin on it as well as me and as a result i bought the Canon 24-70mm 2.8L lens... Again! However, they said if i had any problems whatsoever to take it back and they would refund or exchange. I bought some other stuff and they knocked a fair bit off so i was well chuffed.

I got home and have been practising with both camera and lens, and put it on my 300D as well. the images are much sharper compared to the initial lens. After experimenting at different apertures and shutter speeds and lighting conditions I have come to the conclusion that I need to hold the camera more steady, but apart from that things are much improved.

I have set my camera up to the settings recommended above and have gone for Partial metering after much experimenting.

So thanks everyone for your advice, I am much happier now!