Canon EF 75-300mm III Lens and M31

1257 views
9 replies
1 rating 2 rating 3 rating 4 rating 5 rating
  • Member since
    July, 2003
  • From: Eastern SD.
Canon EF 75-300mm III Lens and M31
Posted by johnjohnson on Sunday, November 24, 2013 1:38 AM

I bought this lens to mess around with. I had read some reviews and it is not one of Canon's greatest achievements. Oh well. I thought I would see about using it for image scaling. I set up for some down and dirty shots. Polar alignment was minimal due to the cold tempretures. I mounted the camera and lens on my old mount that has dual axis controls. This old mount has seen better days. Here is a picture of the camera and mount.

I started out using Back Yard EOS. I was limited to 30 second shots due to a street light across the street and what must have been ice particles in the atmosphere. All shots were taken and saved as JPEG's, no RAWS. In this screen shot you can see the local temps in the upper right hand section of the picture. Due to the very cold, the camera chip was running cool (32F) also so I bumped the ISO up to 12800 at 30 second exposures! Remember now I'm just seeing what M31 looks like at 300mm focal length, not out to do any great image captures. Here's the screen shot. You can see in the image how washed out the captured images are. Very whitish pink.

So now I am capturing images and notice some things about Back Yard EOS (BYE). Downloads seem to take way longer than the Canon EOS Utilities. I also noticed that BYE seemed to be adding something to the images. This became quite aparent when I processed them through Deep Sky Stacker. I don't know whats going on with BYE but all the images seemed quite noisy and loaded with cromatic abberation. I was about to sell this lens! I thought it was a piece of junk. Here is a DSS processed image final as saved by BYE. I wasn't very impressed.

I decided to compare it to the EOS Utilities and used the same settings of 12800 ISO and 30 second subs and saved as JPEG's no RAWS. Image downloads were imediate as compared to BYE. I also noted that DSS processed the images nearly twice as fast as the BYE images. ??? I don't know but seems like Canon EOS Utilities is much faster than BYE and adds nothing to the images. Here is a DSS stacked image using EOS Utilities. The fuzziness is gone and so is the cromatic abberation!

Some will debate that JPEG's are not the best way to save images and indeed they are not, but for speed they are what I used under these conditions. BYE may very well do better in the handling of RAW images. I will have to test this on another warmer night with the same setup.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

  • Member since
    June, 2009
Posted by StarFarmer on Sunday, November 24, 2013 7:57 AM

So what do you think of the lens JJ?  I only have the stock Canon 18-55mm to compare to my Canon 75-300mm.  I always thought the quality of my images suffered more from the Canon XSi than from the lenses.  My daughter's T3i with the same lens(es) produces way better images because of the range of its settings and greater pixel count.

**********************************************************************************************************

 Member since the spring of 2009.  Born 1958.  NW OK.  LX-200 EMC Classic (10") 

Explore Scientific 127mm APO Triplet.  Celestron CGEM mount available for both.

  • Member since
    November, 2009
Posted by Poppa Chris on Sunday, November 24, 2013 9:41 AM

I think the reason BYE is taking longer to download is that the camera needs to do JPG compression before Bye can download it to the laptop.  Also the download time can be governed by your USB speed.  When shooting RAW BYE 3.0.2 does all of this in the background so there should be no noticeable delay between image captures.  Further, make sure that your in camera "long exposure noise reduction" is turned OFF.  You will be dealing with noise during post processing anyway.

---Poppa Chris---

Denham Springs, Louisiana USA

"Second star to the right - Then straight on until morning!" - Peter Pan

Celestron CPC1100GPS (XLT) - 279mm aperature, 2800mm Focal length. (f10) Celestron Ultima LX (70deg AFOV) Eyepieces 32mm thru 5mm, Canon EOS Rebel T2i DSLR, Backyard EOS imaging software, Orion Star Shoot Planetary Imager IV, Celestron Skymaster 15x70 binoculars

 

  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Sunday, November 24, 2013 12:25 PM

StarFarmer

I also had an XSi. I would still have it, but it was stollen in a buglary. It was a bit noisy as compared to the T3i's.

Here is some information on Canon camera's. Testing was done by Gary Honis. I am very tempted to upgrade my camera to a 600D / T3i after reading this review. Maybe your daughter will let you use her's?

Gary Honis Canon Camera Reviews

I would give this lens a B+ rating. There is a tad bit of cromatic abberation. If you look closely at my 2nd M31 image in close up, you can see a blue tinge around the brighter stars. Not bad, acceptable. I think this lens would be fine for terrestial use. As for Astro Photography (AP) at 300mm not so much. It would surely perform better at shorter focal lengths in the 250mm and down. It is light weight which is a plus and mine was very smooth to focus manualy even at the 9deg F that it got down to that night. At $200 it is a great bang for the buck lens. It comes with a lot of Canon "Kits" so it is a tried and true performer. As a kit lens it enjoys a high production rate that keeps it's cost down.

Poppa

You will notice from my screen shot that I am using BYE 3.0.2. The camera must do JPG compression weather dowloading to BYE or EOS Utilities. EOS Utilities takes about 2 seconds. BYE will not start taking another image untill "BYE" quits downloading (about 3-5 seconds). I have used this software since 2011 in it's V2 form and just recently upgraded to 3. I am quite familliar with it. Also with my camera. I would never use the on board camera "noise reduction", or the hi ISO 'noise reduction", or anything that might slow an imaging session. Most times I shoot RAW subs but for the purpose of this night I thought JPEG would be faster as it is the native format of the camera to deliver a smaller file size format over a USB connection. I am using a USB 2.0 single dedicated port with a "premium" 10ft cable. No hub  (shouldn't matter anyway). I have had problems with the first release of V3.0.1 BYE and had some discussion with Guylain Rochon, the BYE developer. It turned out to be some camera specific anomolies (to the 500D / T1i) (fixed with release 3.0.2). This may be what I am experiencing again.

I invite you to an experiment. This is what I intend to do to test the 2 softwares. This can be done indoors using dark frames. Set up an imaging session using BYE for 20 3min subs downloading RAW's and time the session using a stopwatch. Do same downloading JPG's. Same setup for Canon EOS utilities doing RAW's then JPG's. Compare times.

Now process the images using your favorite frame stacker. Same settings used each time. Time each session and compare times.

Now compare processed images. Which ones are noisiest?

I would be very interested in the out come of this experiment. It may be that my camera is the culprit (again) here. It may not be at fault and we can provide some feedback to Guylain for the next rev of BYE.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

  • Member since
    June, 2009
Posted by StarFarmer on Sunday, November 24, 2013 1:35 PM

This is an image of my XSi piggybacked and my daughter's T3i through the Explore Scientific 127mm APO.

 photo DSC05125.jpg

The T3i through the scope "holds the image together" better than the XSi (even at that distance).  I never swapped them out to compare though.  I think your images are very, very good.  I would be proud of them if they were mine.  I'm not very good at post processing, but hope to improve.  I gotta run.  I need to haul water to the cows because of the extreme cloud cover, snow, and ice.  Solar wells don't work too good if we have more than a week of cover.  It also makes it tough to find ISON!  Thanks for the link!  I'll do more reading when I get back in.

**********************************************************************************************************

 Member since the spring of 2009.  Born 1958.  NW OK.  LX-200 EMC Classic (10") 

Explore Scientific 127mm APO Triplet.  Celestron CGEM mount available for both.

  • Member since
    November, 2009
Posted by Poppa Chris on Monday, November 25, 2013 6:10 AM

Sounds like an interesting experiment.  I may have to try it out if I get the time to do it.  But I can say I've not recognized a problem so far with BYE 3.0.2 and my T2i, but I haven't done any JPGs with it either, only CR2 raws.

---Poppa Chris---

Denham Springs, Louisiana USA

"Second star to the right - Then straight on until morning!" - Peter Pan

Celestron CPC1100GPS (XLT) - 279mm aperature, 2800mm Focal length. (f10) Celestron Ultima LX (70deg AFOV) Eyepieces 32mm thru 5mm, Canon EOS Rebel T2i DSLR, Backyard EOS imaging software, Orion Star Shoot Planetary Imager IV, Celestron Skymaster 15x70 binoculars

 

  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Saturday, November 30, 2013 2:36 AM

I got some testing done with BYE and CR2 RAW files. Instead of doing 3 minute subs I did 30 second subs to speed up the testing.

Here were my expectations. I was going to take 30 subs of thirty seconds each at ISO 1600. This would equal 15 minutes of image data. If I tacked on another 2 seconds to each image for download time this should take 16 minutes for an imaging session.

The first run with BYE I had all the bells and whistles on. I was reading and writing Exif data. This gave nice little readouts of the sensor temperture, local weather for temp humidity and other things and imbeds this information in the image file. Nice if you care. First run began at 12:33 am on the dot and finished at 12:57.20 am. The image session to get 15 minutes of data took 24 minutes and 20 seconds! 8 minutes 20 seconds longer than expected!

Next I ran BYE with the read and write Exif data skipped. It helped a little. Start time 1:04 am on the dot. Finish time 1:26.05 am. 6 minutes 5 seconds longer than expected with a total time of 22 minutes 5 seconds!

I ran EOS Utilities next using the same parameters. There is nothing to turn on or off with EOS Utilities. Start time was 1:29 am on the dot and finish time was 1:45.15 am. 15 seconds over the expected time of 16 minutes, allowing for 2 seconds between subs. Brutally effecient! No bells and whistles. Just a Utility like it says.

To me the fancy dashboard skin, weather readouts, sensor tempertures, multiple thumbnails, RGB histograms, are not worth standing outside for another 6 to 8 minutes when it's freezing cold.

I think BYE makes a fine focusing tool and that's what I will use it for but for the actual image captures I will use EOS Utilities for now. Matter of fact is, EOS Utilities can focus quite well also using live view and software zoom, if you have a bahtinov mask (or not).

I will test JPG's soon to see how that works just for those who do not have software that handles RAW images (Like Registax) or RAW to TIFF conversion. Some times one has to process just JPG's like the time I forgot to change my camera settings and had 150 3 minute subs! A whole night of imaging, I wasn't gonna waste the data by not processing it!

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Saturday, November 30, 2013 5:10 AM

Stayed up all night doing processing. I ran all the RAW images through Deep Sky Stacker as Dark images. Each of the 30 images were processed into a master dark.

For BYE with the EXIF data images the processing took 9 minutes 45 seconds.

For EOS utilities images the processing took 6 minutes 10 seconds.

So here are some screen shots of the processed Darks for each.

First is the BYE RAW DARK NOISE:

This is the EOS RAW NOISE:

Next I show you a BYE FULL FRAME RAW NOISE:

And this is the EOS UTILITY RAW FULL FRAME NOISE:

So you can see from these images that BYE is noisier than the EOS Utility in capturing images even in the RAW format. Kind of what I expected.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Saturday, November 30, 2013 9:42 AM

Next I did another run using BYE to capture 30 JPG subs of 30 seconds each at ISO 1600. It took BYE 23 minutes 2 seconds to capture 15 minutes worth of data.

EOS Utilities did it in 16 minutes 10 seconds. Again much faster than BYE.

I then processed all the images again in DSS.

Here is the BYE JPG DARK NOISE:

This is the EOS JPG NOISE:

This is BYE JPG FULL FRAME NOISE:

And this is the EOS JPG FULL FRAME NOISE:

You all be the Judge. I did this as controlled as I could with constant tempretures and all DSS settings the same in all test runs. The only differences were the capture softwares being BYE vs. EOS Utilities.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

  • Member since
    July, 2003
  • From: Eastern SD.
Posted by johnjohnson on Sunday, December 15, 2013 2:25 AM

Finialy finished with all the data I had captured of M31 with this EF lens. This is 60 JPG subs of 30 seconds each at ISO 1600. Captured with Canon EOS Utilities. Stacked with Deep Sky Stacker 3.3.3 beta (saved as a 16 bit Tiff) and processed with Canon Digital Photo Professional as a TIFF file. Then processed with Photo Shop Elements 8 as a TIFF file. Converted back to JPG with Canon Digital Photo Professional EXIF embedded JPG.

JJ

20" F5 Obsession, OMI mirror .987 Strehl. 10" F4.7 reflector. 6" F5 ST reflector. 120mm F7.5 EON. 80mm F11.3 guide scope. SkyWatcher EQ-6 Hyper Tuned.   Flicker Astro Site   More Astro Images

Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.

ADVERTISEMENT

FREE EMAIL NEWSLETTER

Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter.

ADVERTISEMENT
ADVERTISEMENT
Find us on Facebook

Loading...