Sigma 150-600mm lens came today!

[Tintype_18]

It was on sale so I ordered it Monday afternoon and got it about lunch time today! B&H was most helpful in setting up an account. Probably won't be using it for a while as SWMBO set her foot down, "No more stuff for your camera!" Package came in perfect condition. Everything checked out and need to read the manual as it seems to cover a wide range of possibilities for photos. We are on a flyway for the sandhill crane migration. I have take some photos but my 300mm lacks the needed close shots. Looking forward to learning to use it and post photos in the future.

Any advice/suggestions are most welcome.

[Tronhard]

960 is the Equivalent Field of View that you achieve when you use the lens at 600mm on a Canon APS-C sensor.  Thus: 600mm x crop factor of 1.6 = 960mm.
See my article HERE on Equivalence (Ernie don't look... 🙄, you'll only get upset 🙂) 
HINT: If you open up the link, go to the bottom of the screen and click on the magnify icon, then select Page width for a nice clear display - avoid the OPEN option on the top right, as Word will try to convert it back from a PDF and it gets rather pixely...

[ebiggs1]

The Rebel T7 has a built in crop factor of 1.6.    600mm x 1.6 = 960mm.

960mm FL is serious FL and requires a serious effort on your part to use it to its fullest.

[shadowsports]

600mm x 1.6 crop factor...  960mm equivlent on APS-C

Ernie hates when he hears this word.  LoL 

FW 2.01 comes with an improved algorithm for IS...  You don't have to get the dock. I use mine infrequently, and have never had to make a focus adjustment, but if you are going to own Sigma lenses..  its worth the $60 in my opinion.

[ebiggs1]

---

Ernie hates when he hears this word.  LoL 

 😁

Only when it is used in a misleading way. It crops nothing. Never did, never will. The AOV is the only thing that changes.

[kvbarkley]

In this case it makes sense since the 1/FL rule for handholding is based on 50mm equivalents.

[Tronhard]

Ernie.  The  focal length of a lens is a physical characteristic of the lens and doesn't change, thus its Angle of View remains constant. To suggest the focal length gets longer on a camera with a smaller sensor is incorrect.   What changes with a smaller sensor is what it captures, which is an area smaller than that of a Full-Frame sensor.  Full-Frame is a pretty standard term in the photography industry and you seem to get a burr under your saddle at its use, along with the term Crop Sensor.  Both are accepted terms.   The smaller sensor CROPS what is projected by the lens.  The Focal length doesn't change - it's simple physics...

[Tintype_18]

So much to learn. I'm almost tempted to crawl up into the attic and get the old Kodak Brownie camera. Now to find film. I have been looking at the instructions and, just when I thought I had it figured out, more pops up. This will be a learning experience for me. I write outdoorsy stuff with photos. I might have to coach the wife on this lens...after I learn how to do it myself. The T7 will take care of a lot of photos but there are some that will require the Sigma lens- bears and elk in TN and NC. "Go ahead, dear. Get a bit closer for a great shot. Oh yes, is your life insurance paid up?"🤔

Again, thanks to all for your help, advice, etc.

[ebiggs1]

I was not going to respond to your reply because it is such a contentious and hotly debated subject. Of course, the physical characteristics  of any lens cannot and never changes. However, current opinion by some even most people concerning crop factor claim it does. It is in my opinion more accurate to say the AOV, or angle of acceptance does change. This is because of the smaller sensor. Nothing about the lens.

There is a great deal of confusion surrounding crop factor, and it is difficult to explain. The sensor in a so-called crop sensor camera does not crop a single thing. A lens produces a circular, or round, image not a square or rectangular one. A camera sensor, or film for that matter,  in a camera captures that rectangular portion of this lens image circle. If you use 35mm film as a standard, any camera with a sensor smaller than 35mm film, will cover a smaller portion of the image circle. It will change the field of view, AOV or angle of acceptance of a given lens, that is seen by the camera.  Even your holy grail of a FF sensor wastes or ignores the data, light, that is out of the image circle.

I only exists to calculate the angular measurement, or AOV, into an understandable tool for old 35mm photographers, like me, to figure out the actual field of view, AOV, of a given lens if we decide to use a crop sensor camera. New photographer don’t use it or need it as they really don’t have a reason to compare it to anything. All they know is the 18-55mm kit lens has perfect FL and AOV for their general needs.

If we are to give in to your way of thinking every sensor that is not a 35mm has an equivalent mathematical factor. Medium format, large format even your iPhone has a lens factor equation vs 35mm. The good thing is we don’t do it.

There is one good point in this discussion, “In this case it makes sense since the 1/FL rule for handholding is based on 50mm equivalents.”, brought up  kvbarkley.  A shutter speed, SS, below 1/1000 will require extra effort to get sharp photos. “…it's simple physics...”

[ebiggs1]

When I did my DSLR 101 classes very few had ever heard of crop factor. As long as you don't care to make a comparison to 35mm, or so-called FF, crop factor is nothing more than a frustrating term to complicate photography.

Now add the fact you have false even incorrect information off the ole inner web about how almost magically your lens changes it  focal length, FL, and it is simple to see how much of a mess crop factor is.

If you are a person that loves and delights in using crop factor please feel free to do so. I am not one of those people.

[Tronhard]

Ernie, to quote your own post:
" The Rebel T7 has a built in crop factor of 1.6. 600mm x 1.6 = 960mm. 960mm FL is serious FL."
It would be easy to infer from your statement that you are suggesting the FL is changing, when in fact I am pretty sure that is not the case.  Although you say the sensor does not crop anyting you still use the term crop factor when you describe its impact on the resulting image, which I find confusing. Hence my contention that terminology is absolutely critical in this discussion, and we are not served well by that from the very beginning.