topic Re: 70-30 IS I blurry with Canon RP? in EF & RF Lenses

70-30 IS I blurry with Canon RP?

dqschwab — Mon, 14 Dec 2020 22:44:47 GMT

Hi all -- I have a Canon RP and it works very well with all my EF lenses except for my 70-300 IS I. For that lens, my pictures come out extremely blurry at all focal lengths and is only sharp in the center (improves slightly by stopping up). I didn't have this issue with my 6d mark ii, where photos were more or less sharp from end to end.

I've included some photos for reference. Curious to hear thoughts on what might be happening. Both photos are taken stopped down by at least 2 stops.

Re: 70-30 IS I blurry with Canon RP?

Waddizzle — Mon, 14 Dec 2020 23:29:00 GMT

Your subjects and details are simply too far away in these sample photos. Period. Test the lens on subjects that are 10-20 yards/meters away from the camera.

Re: 70-30 IS I blurry with Canon RP?

dqschwab — Tue, 15 Dec 2020 07:25:00 GMT

Even from a closer distance, there is blur. The below photo is at ~250mm from 25 feet away or so at f11 and it's still very blurry at the corners. Any thoughts?

Re: 70-30 IS I blurry with Canon RP?

Waddizzle — Tue, 15 Dec 2020 13:19:22 GMT

It is blurry at the corners? What about the center of the image? Image quality along the edges and corners of the frame is what separates consumer lenses from professional grade lenses.

Re: 70-30 IS I blurry with Canon RP?

ebiggs1 — Tue, 15 Dec 2020 15:46:17 GMT

I would say that is normal for that lens. You really can't compare a lens IQ when using two different camera bodies.

Re: 70-30 IS I blurry with Canon RP?

shadowsports — Tue, 15 Dec 2020 15:58:13 GMT

Greetings,

I did some peeping and have tp admit the corners of his pas image were pretty soft. The image was shot Av Priority with F11 and 1/100. ISO was 1600. This shouldn't be too much of an ask for an RP. The center looked nice.

A better option might be

EF 70-300mm f/4-5.6 IS II USM Refurbished | Canon Online Store|Canon Online Store

Which I actually own myself and have been impressed with overall. I bought it for a trip to Russia and was happy with the results.

As Ernie points out, completely different body's comparatively.

Re: 70-30 IS I blurry with Canon RP?

Waddizzle — Tue, 15 Dec 2020 21:44:11 GMT

@shadowsports wrote:
Greetings,
I did some peeping and have tp admit the corners of his pas image were pretty soft. The image was shot Av Priority with F11 and 1/100. ISO was 1600. This shouldn't be too much of an ask for an RP. The center looked nice.

As Ernie points out, completely different body's comparatively.

I thought the entire image looked soft. But that might just be the forum file size limits kicking in.

I agree, it is not the sharpest lens Canon makes. I think the 1/100 shutter speed is just WAY too slow for a 300mm lens. I always try to follow the 1 / FL rule, no matter whether or not the lens has IS or not. I see no reason for this to have shot at f/11, either. It is a flat wall.

In fact, the flat wall just might explain why the corners are soft. The plane of focus is curved, not flat. I would need to check a DoF table to see if the corners are still within the range of "acceptable focus".

Re: 70-30 IS I blurry with Canon RP?

ebiggs1 — Thu, 17 Dec 2020 15:23:20 GMT

It is possible you have a decentered element. Your lens is not a good candidate for repair though.

Re: 70-30 IS I blurry with Canon RP?

FloridaDrafter — Sat, 19 Dec 2020 03:04:11 GMT

@shadowsports wrote:
Greetings,
I did some peeping and have tp admit the corners of his pas image were pretty soft. The image was shot Av Priority with F11 and 1/100. ISO was 1600. This shouldn't be too much of an ask for an RP. The center looked nice.

A better option might be

EF 70-300mm f/4-5.6 IS II USM Refurbished | Canon Online Store|Canon Online Store

Which I actually own myself and have been impressed with overall. I bought it for a trip to Russia and was happy with the results.

As Ernie points out, completely different body's comparatively.

Totally agree.

I have both of those lenses as well. I used the EF 70-300 IS USM on a T4i for many years and was quite happy with it, however, I cropped a lot away and the center is pretty sharp. Then when my wife got back into photography (retired film shooter), she took the T4i for a while then I bought the EF 70-300 IS USM II and the T7i for her to use. The 70-300 mark II pairs nicely with the T7i for her needs, the rig is light as a feather and she gets great results, but she knows what she is doing. I've tried the 70-300 mark II on my 7D2 and 5D4 and it's pretty good, not like my L glass, but pretty darn good.

So, to add to this discusion. I agree that the OP's last image is soft on the edges, but from experience with that lens, I think it is the lens. The EF 70-300 mark II is a big improvement and not a bad price. I also bought the 70-300 IS USM L refurbished, so you can't omit that one. I used that with the T4i with great results, but it is too heavy for my wife and the T7i, so it spends its time on the 7D2 as a backup.

Newton