EF 300 F4L not that sharp

[images_in_light_north_west]

I must admit a little disapointment in my new EF300 F4L, my EF 24-105 F4L

appears sharper, does that seem right ? I would have thought the prime to be

sharper its also not as fast to focus. Any thoughts ? bad copy ? or mormal

[fp56gallery]

My f4 300 L is uncredibly sharp. Maybe you got a bad copy?

[bobatkins]

I suspect user error unless you have a really bad sample.

 

You did have it on a tripod I assume?

[lester_wareham]

What I noticed with mine when I tested it was a definate peak in sharpness at f5.6 to f8 after which it dropped off, being about the same sharpness at f11 as for f4.

 

I would say it has similar sharpness to my 200/2.8L and 50/1.4 and a bit less sharp than the 100/2.8 Macro USM.

[pturton]

My 300 f/ IS is sharp wide open - as sharp as my 400 f/5.6 but not quite as crisp as my 135 f/2. With my 300 the IS seems to take longer to settle than the IS on my 70-200. When using a tripod I turn IS off but leave it on for use on a grain bag and handheld. Without practice, the IS should allow you shutter speeds of 1/100 second and yield good results unless your subject moved ;-)

 

By the way, do not use an UV protective filter with this lens unless the environment is harsh - blowing sand, salt spray and etc. The front element is a protective element. Use of a filter can impede focus and add flare.

[whwhitejr]

Ross, I was disappointed with my copy at first as I was comparing it to my 70-200f2.8LIS on fast moving aircraft. I found that it(300mm) wouldn't focus as fast and gave me about 3 useable frames out of 10 as compared to the 70-200@7 out of 10. The next day I figured out that it was just the difference in the extra focal length. By starting my pan early I got much better results. (both lenses with IS) What I'm getting at is as you go up in focal length thingh get real shakey after 200mm. Try them both at about 1/1000 of a second and then compair them. Regards,Bill

[awindsor]

It is hard to be objective. Perhaps you could purchase a copy of Imatest and get some objective numbers. You could compare the 1.6x crop numbers with the good sample on PhotoZone.

[images_in_light_north_west]

I have tried it hand held and on a tripod, it has IS so you should be able to hand hold it in bright light, have not done a comparable test yet will try this week end shooting the same subject with both lenses, maybe my expectations are to high, does anybody know the sweet spot to test it at for sharpness ?

 

Thanks everyone

 

Ross

[PuppyDigs]

I have a 1995 EF 300 4L USM and it is deadly sharp wide open at F4. In fact I rarely use it

at

any other aperture. I also have a 24-105 4L and it's a sharpie. It's really difficult to

compare

the 2 as DOF is so shallow with a 300mm optic.

 

As go AF speed, they're both so fast I can't tell a difference. Both are faster than my EF

70-200 4L.

 

However, focus errors are painfully apparent with a telephoto. If AF locks onto the wrong

plane or needs calibration, it will look much more out of focus than a shorter optic.

Maybe you should do a focus test and make sure you're not suffering from back or front

focus issues.

[bennyboy]

Perhaps post up a sample photo for our perusal? With EXIF info intact if possible.

[images_in_light_north_west]

'Perhaps post up a sample photo for our perusal? With EXIF info intact if possible.'

 

how do you keep EXIF when downloading to PN ?

[phule]

Unless you use Photoshop's "Save for Web..." the EXIF info should remain intact. If not, why not copy/paste the important parts of the EXIF info into the reply in this thread?

[andrew robertson]

Call Canon. They can service the lens if it is defective. It may be that there was some

problem such as the lens being in mode 2 for a stationary subject.

[images_in_light_north_west]

sample shots on tripod no IS at 20ft f4@1/100s,f5.6@1/50s,f11@1/13s

maybe its just me

[images_in_light_north_west]

f5.6

[images_in_light_north_west]

shot with 30D,300mm f4L, small fine, standard mode, spot meter, timer

 

thanks again, Ross

[lester_wareham]

BTW I did some tests to understand how effective the IS was on mine when I got it. There were two interesting conclusions:

 

a) Mode 1 and Mode 2 are equally effective handheld.

 

b) Mode 2 is much more effective than Mode 1 on a monopod, smae probably applies to a beanbag also.

[digitmstr]

I think they are in focus and reasonably sharp.

 

You should keep in mind that your test subject is round therefore there will be really only one *very* narrow plane within the DOF. Then, it will gradually soften around the circumference.

 

Try a different target as well; take a portrait of someone and see how it looks.

[bennyboy]

I agree with Giampi, I'd be very happy with those shots, the noise isnt bad at those ISO settings either.

 

It would be interesting to see comparison shots of the same target from your 24-105.

[fp56gallery]

Looks fine for me. Not the best test motive, though.

[matt_sallis]

The 2nd shot you posted looks the best to me (1/100th @ f4) which suggests that the slight blur on the other 2 is purely a matter of camera shake (1/13th of a second at 300mm!?).

 

There is no reason to turn IS off when tripod mounted, as you will still get some degree of camera shake.

Imagine a pencil extending from the camera to the subject. If when you press the shutter the point of the pencil moves even 1/10th millimetre on the subject then you will have blur, as that equates to about 15 pixels.

 

IS on and fast shutter speeds are what get sharp photos, even on a tripod.

[images_in_light_north_west]

'IS on and fast shutter speeds are what get sharp photos, even on a tripod'

 

Every thing on this site and Canon's instructions say turn off IS on tripod.

 

What is the deal ?

[awindsor]

Matt,

 

The 300/4 IS has what is often termed "second generation" IS. This means it has two modes but cannot be used on a (sturdy) tripod.

 

Canon does say to disable the IS on a tripod for the 300/4 (page 24 of the manual). Furthermore thay don't advise using IS at high shutter speeds (page 22 of the manual).

 

There has been some suggestion in other posts that IS at higher shutter speeds actually softens then image. I cannot confirm whether this is true.

[matt_sallis]

Hi Alistair,

 

My findings come from using a 600mm f4 coupled with 1.4x or 2x extenders (sometimes both), so even on a Gitzo 1548 with gimbal or fluid video head, there is still quite some movement at longer distances (as I found yesterday photographing a purple heron at about 200 metres).

 

I don't know if the 300mm f4 has a different IS system, but the 600mm certainly still needs the IS switched on.

 

When I say fast shutter speeds, I mean as fast as can be achieved, rather than stopping down unnecessarily. For instance yesterday with 600mm + 1.4x + 2x I was at an effective aperture of f11, then stopped down 1 more f stop to regain contrast, and in the murky conditions could just about get to 1/100th @ 800 iso! I would be very reluctant to use a telephoto below 1/100th second, and certainly not at 1/13th with IS off.

 

Ross,

 

If I may suggest, perhaps the best solution may be to try with IS on, and with IS off, and see which gives the best results. It may be that your tripod is not steadying the lens as firmly as needed.

It looks to me like the lens can achieve sharp results with the right conditions, you just need to determine exactly what the minimum requirements for that lens are.

 

Best wishes,

Matt

[matt_sallis]

I have just checked the instruction book for my 600mm f4, and it too states that you should turn IS off when tripod mounted.

 

Everyone I've heard from who uses this lens says leave it on though, and in practive I have found it needs to be on for best results. I also leave IS on with my 300mm f2.8, and so I would assume the same is true of the 300mm f4.

 

BTW the instruction book also says that extenders can only be used 1 at a time, although there is a drop in quality this is also not true.

 

Cheers,

Matt