moon shot with ef600 f4II

for those who are curious about adding tc on ef 600mm f4II, here are 2 moon shots with and without 1.4xIII TC. the lens IQ takes a big hit when TC is added. i haven't taken my lens on field tour yet i do have the 2.0xIII TC as well and i didn't bother with it because i knew it'll look awful. i have PPed the shots on my uncalibrated laptop so i don't know how it'd look like on your monitor. please let me know if the posted photos look weird on your monitor. the RAW pictures look very nice and sharp with excellent contrast on my monitor. any comment is welcomed.

cheerz.

EF 600mm f4II /1D4 no TC

EF 600mm f4II+1.4x TC

rebel99 wrote:

for those who are curious about adding tc on ef 600mm f4II, here are 2 moon shots with and without 1.4xIII TC. the lens IQ takes a big hit when TC is added. i haven't taken my lens on field tour yet i do have the 2.0xIII TC as well and i didn't bother with it because i knew it'll look awful. i have PPed the shots on my uncalibrated laptop so i don't know how it'd look like on your monitor. please let me know if the posted photos look weird on your monitor. the RAW pictures look very nice and sharp with excellent contrast on my monitor. any comment is welcomed.

cheerz.

the bare 600 shot looks fantastic.

I am puzzled by the bad quality of the 1.4x image ???

Are you sure everything was done properly?

My 300 II sees almost no degradation with the 1.4x III on it - could it be that you had not focussed perfectly or any other user flaw? If the degradation is that big I would not like to use it - my 300 looks better with the 2x III on it (if I recall my images right)

which body did you use?

Bare the 600 looks excellent on my monitor.  Great shot.  I too am a bit puzzled by the performance with the TC, didn't think it would be that bad.

Iron Mike wrote:

the most obvious difference, is that the moon looks different, and was not photographed at the same time. Again, looking at the exif it seems likely that the atmospheric seeing conditions on the 20th (600+1.4X shot) were not as good as the day of the first shot.

+1  Atmospherics play a huge role in IQ.  That is unless your TC is in fact bad.

R2

rebel99 wrote:

yes indeed, i am puzzled as well to the degree of iq degradation when tc is added. but i think there must be a different reason and i need to investigate the reason. thanks for replying.

cheerz.

To me the one with the TC looks backfocused. Maybe MA will fix it!

I think Iron Mike might be on track with a lot of the image degradation. While I don't own the 600, but have the 400 2.8 I've found that absolute image quality is attained one or two stops from wide open with these lenses, so f4-5.6 for me, f5.6-8 for you, but throw on the 1.4 tele converter and you'll need to go another stop again to maintain the lenses native aperture, so reporting f8-11. Also maintaining aperture is a given for comparing image quality. I noticed also that the shutter speed was pretty high. Unless you're shooting hand held you'd be better off reducing shutter speed for lowest iso. I've shot the moon on my 7D surprisingly clean at 1/50th (I found this to be about as slow as I could go before getting motion blur) while using both a 2xII and a 1.4xIII behind my 400 at a true f11, one stop from wide open. A day or two later I tried the same setup and settings on my 5DII, but the quality wasn't as good, so apparently clear nights do vary a lot as others have said.

The shot below is the one from my 7D, straight from raw conversion so it'll clean up a bit better than this. Also you can see the exif doesn't report double stacking of tele's, hence the info saying 800mm f8.

AOKH wrote:

To me the one with the TC looks backfocused. Maybe MA will fix it!

Right, backfocused... because the edes seem more in focus and they are obviously further away than the center. Never mind the moon is two hundred million miles away - the shallow DOF of the 600mm can clearly separate the edges from the center!

Here in America we are proud of the public school education. And although our kids rank the last in in science, they rank #1 in self confidence.

Heard this yesterday.

The 600f4 II plus 1.4x extender don't work optimally on a 1DMkIV or any older body. By this I mean focus speed, accuracy, and resulting image quality. Apparently that combo works much better on a 5DMkIII or 1DX with almost zero degradation when using a 1.4x III extender.

Yes that is the stuff interweb BS and mythology comes from, but I did hear it while talking to someone about longer than 500mm lenses. Can't confirm it. Don't you have a 1DX now. If so, you could check to see if that is true.

hah!

That is horrible. I have also noticed a drop in IQ with the 1.4 on the 500 II, But it is still very good. But verrry little with the 300 II. Strange.

Personally if my results were that bad I would send the T.C. back to canon with the lens.